About 150 Mesozoic (mostly Early and Middle Jurassic) species of the heterobranch superfamily Mathildoidea are classified into four families and 27 genera. Most taxa are assigned to the families Mathildidae, Gordenellidae, and Tofanellidae while the Triassic family Anoptychiidae holds only a single genus and is restricted to the Late Triassic. Mathilda janeti is designated as type species for the genus Promathildia. Earlier designations are invalid because they refer to species which were not originally included in the genus Promathildia. As a consequence, Promathildia is transferred fromMathildidae to Gordenellidae. The generic assignment of numerous mathildoid species is changed. The suggested classification represents an arrangement which is based on shell characters; it is not based on a cladistic phylogenetic analysis.However, a great number of fossil taxa can only be classified based on shell characters. A high mathildoid diversity has been recognized from the Late Triassic Cassian Formation. Many of these taxa are unknown form the Jurassic and probably became extinct during the end-Triassicmass extinction event.However, at least five genera (probably eight) survived the end-Triassicmass extinction event. Tricarilda, Jurilda, and Promathildia are rather conservative, long ranging groups of high Jurassic species diversity. They probably gave rise to the modern Mathildidae. One new genus is described: Angulathilda gen. nov.
Introduction
The present paper reviews and discusses Mesozoic and especially Jurassic genera and families of the heterobranch gastropod superfamily Mathildoidea. Mathildoidea form a marine group of basal Heterobranchia. The family Mathildidae is usually included in the superfamily Architectonicoidea but also used as superfamily Mathildoidea (Bandel 1995; Bouchet et al. 2005). The modern Mathildidae are of moderate diversity with about 130 nominal species (Bieler 1995). They occur in shallow to deep water and feed on cnidarians (Haszprunar 1985; Healy 1998). There are few studies on the anatomy of this group (Haszprunar 1985) and there are no molecular studies so far. In modern biota, Mathildoidea are relatively rare (Healy 1998). However, Mathildoidea can be common in Mesozoic samples. The undoubted fossil history of Mathildoidea goes back to the Late Triassic (e.g., Kittl 1894; Bandel 1995). The superfamily is especially abundant in Early and Middle Jurassic deposits (e.g., Schröder 1995; Gründel 1997; Kaim 2004). Thus, according to the current state of knowledge, the family Mathildidae was apparently more diverse and abundant in the Mesozoic than today.
Although there is a certain variation in shell morphology of the Mathildidae and closely related families, the group is in general rather conservative in shell morphology. A great number of fossil species have been placed in the genera Mathilda and Promathildia so that these genera became dustbin taxa. In the last 15 years, several new genera have been proposed for Jurassic and Triassic mathildoids based on characters such as the onset and number of spiral ribs and the orientation of the protoconch or the presence of micro-ornaments. The biological meaning of these characters has been questioned by some authors (e.g., Bieler 1995; Kaim 2004). However, the alternative would be to place >100 Jurassic species in the genus Mathilda, a capitulation in terms of phylogeny and taxonomy. Encompassing anatomical and molecular studies of modern representatives of the group are still lacking.Until such studies are published, we consider statements that certain shell characters are useless as pure allegations. However, we admit that the present classification of fossil Mathildoidea represents an arrangement, which is not based on a cladistic phylogenetic analysis. In the absence of a clear phylogenetic framework, the here suggested arrangement is nevertheless justified.
The present work focuses on the type species of Jurassic mathildoid genera. Each genus will be discussed according to its morphological characters and its temporal occurrence. Moreover, we will try to assign the described Jurassic mathildoid species to the appropriate genera whenever possible.
The present work focuses on the type species of Jurassic mathildoid genera. Each genus will be discussed according to its morphological characters and its temporal occurrence. Moreover, we will try to assign the described Jurassic mathildoid species to the appropriate genera whenever possible.
A large number of Jurassic mathildoid species haven been placed in the genus Promathildia Andreae, 1887. As will be shown below, the traditional designation of the type species of this genus is invalid. A new type species is designated here and this changes the concept of the genus Promathildia considerably.
Systematic palaeontology
Superfamily Mathildoidea Dall, 1889
Families included.—Mathildidae, Gordenellidae, Tofanellidae, Ampezzanildidae, and Trachoecidae; the assignment of Anoptychiidae to Mathildoidea is questionable because the protoconch of the type species of Anoptychia is unknown. According to the current state of knowledge, all are extinct except Mathildidae and Tofanellidae (the latter only if the modern Graphis is really a member of this largely Triassic—Jurassic group). The following classification of Mathildoidea is used herein:
Family Mathildidae Dall, 1889
Genus Mathilda Semper, 1865
Genus Tangarilda Gründel, 2010
Genus Jurilda Gründel, 1973
Genus Tricarilda Gründel, 1973
Group of Turritella binaria
Genus Gymnothilda Schröder, 1995
Genus Bathraspira Cossmann, 1906
Genus Carinathilda Gründel, 1997
Genus Angulathilda nov.
Genus Erratothilda Gründel, 1997
?Family Anoptychiidae Bandel, 1995
Genus Anoptychia Koken, 1892
Family Gordenellidae Gründel, 2000
Genus Promathildia Andreae, 1887
Genus Gordenella Gründel, 1990
New genus to be described by Nützel and Gründel
Genus Turritelloidea Walther, 1951
Genus Camponella Bandel, 1995
Genus Proacirsa Cossmann, 1912
Genus Schafbergia Gatto and Monari, 2010
Family Tofanellidae Bandel, 1995
Genus Tofanella Bandel, 1995
Genus Cristalloella Bandel, 1995
Subgenus Cristalloella (Cristalloella) Bandel, 1995
Subgenus Cristalloella (Wonwalica) Schröder, 1995
Genus Graphis Jeffreys, 1867 (synonym: Rotfanella Gründel, 1998)
Genus Neodonaldina Bandel, 1996
Genus Usedomella Gründel, 1998
Genus Camponaxis Bandel, 1995
Genus Urlocella Gründel, 1998
Genus Conusella Gründel, 1999a
Genus Reinbergia Gründel, 2007b
Emended diagnosis.—The majority of Mathildoidea have slender, high-spired shells and are of moderate to small size. The protoconch is heterostrophic. It consists of 1.5 to 3 sinistrally coiled whorls which are smooth in most species but may have axial ribs in some. The shell axis of the protoconch may be 90° (transaxial) to 180° (coaxial) to the axis of the teleoconch (see Schröder 1995 for terminology). The teleoconch ornament consists principally of several spiral ribs crossed by numerous axial ribs. Intersections between spiral and axial ribs may or may not be nodular. The teleoconch whorls are commonly angulated or keeled at one of the spiral ribs. Micro-ornaments occur in some genera. Some forms show a pronounced ontogenetic change of the teleoconch ornament including a changing position of the spiral ribs or a complete reduction of the ornament.
Family Mathildidae Dall, 1889
Remarks.—The family Mathildidae is based on the modern genus Mathilda that has a Pliocene type species. Numerous Triassic to Recent species and several genera are assigned to this family. However, there is no report from the Palaeozoic. Mathildidae are most diverse in the Jurassic and are represented by a large number of species. The principal morphology of the group is rather conservative but various character combinations occur. Few characters seem to be suitable to recognize genera so that the systematics of the Mathildidae is difficult. The number of spiral ribs on the whorl face of the early teleoconch, immediately after the protoconch (primary spiral ribs) seems to be a useful character for a classification on the genus-level. In Mathildidae, there are 2, 3, 4 and sometimes more primary spiral ribs. The spiral rib directly at the suture is here not regarded as a primary spiral rib.
Gründel (1973) used the number of primary spiral ribs for a subdivision in genera and subgenera: Jurilda (later Promathildia) with two primary spiral ribs, Tricarilda with three primary spiral ribs und Turritelloidea (later Turrithilda respectively Mathilda) with four and more primary spiral ribs. Other authors considered this subdivision as artificial (e.g., Bieler 1995; Kaim2004). Kaim(2004) treated Tricarilda-and Turrithilda-species (3 and more primary spiral ribs) under the genus name Mathilda. However, those with two primary spiral ribs were assigned to Promathildia although this character was generally not considered valid by him. Bieler (1995) investigated Recent mathildids and concluded that it is unclear whether the character complex of spiral rib pattern is suitable to recognize monophyletic genera and that anatomical studies (and one may now also say molecular studies) are needed to test whether this pattern give a phylogenetic signal. These doubts may be justified but the need for a subdivision of the large number of fossil mathildids remains. For Jurassic mathildids the number of primary spiral ribs seems a readily available character which in combination with other characters facilitates a subdivision in genera. However, we are aware that this procedure is artificial to some degree. This problemis typical for highly diverse fossil groups which have notoriously conservative shell morphology.
Additional characters which may be used for a taxonomic subdivision are shell shape (e.g., unusually broad and strongly keeled shells) and the presence of a micro-ornament consisting of numerous fine spiral ribs. This micro-ornament seems not to be strictly diagnostic on the genus level; it is for instance weakly developed in some species of Jurilda and Tricarilda but is characteristic for the genera Carinathilda, Angulathilda, and Erratothilda.
As outlined below, the diagnosis of Promathildia is changed because of the new designation of a type species. For those Jurassic mathildids with two primary spiral ribs (Promathildia sensu Gründel 1997 and Kaim 2004), the name Jurilda Gründel, 1973 is available. Tricarilda Gründel, 1973 can be used for species with three primary spiral ribs. Mathilda Semper, 1865 (with modern type species) is used for species with four and more primary spiral ribs.
Genus Mathilda Semper, 1865 Fig. 1A.
Type species: Turbo quadricarinatus Brocchi, 1814; subsequent designation by Boury 1883; Pliocene, Italy.
Included Jurassic species: Turrithilda angulata Gründel, 1997, Callovian; Mathilda makowskii Kaim, 2004, Bathonian—Callovian; ?Mathilda podlasiensis Kaim, 2004, Callovian; Mathilda pseudopalina Gründel, 2007b, Aalenian; ?Promathilda reticulata Jamničenko, 1987 including subspecies, Aalenian to Bajocian.
Remarks.—We include Jurassic species with four or more primary spiral ribs in Mathilda with the exception of Erratothilda-species which have a broad shell and strongly keeled whorls. Moreover, most Erratothilda species have a coaxial protoconch and a distinct micro-ornament and differ from Mathilda in these respects. We leave the question whether the Jurassic species which have been assigned to Mathilda are really congeneric with the Pliocene type species open although we consider it unlikely. Gründel (1976) re-described the type species Mathilda quadricarinata and reported the presence of four primary spiral ribs. In contrast, Bandel (1995: 39) mentioned in his key to Triassic Mathildoidea that Mathilda is characterized by two primary spiral ribs. However, he obviously did not refer to the type species.Most of the modern species assigned Mathilda by Bieler (1995) have four or more primary spiral ribs; however, some have only three.
Walther (1951) introduced the generic name Turritelloidea for species which are here assigned to Mathilda. Schröder (1995) replaced Turritelloidea by Turrithilda because he assumed that the ending “-oidea” can only be used in names of superfamilies—this replacement is of course invalid. The type species of Turritelloidea (Turritella opalina Quenstedt, 1852) is a representative of the Gordenellidae and differs considerably from Jurassic Mathilda-species (Gründel 2005b).
Stratigraphic and geographic range.—The earliest Mathilda is known from the Toarcian; similar species have been reported from the Late Cretaceous (e.g., Mathilda hexalira Dockery, 1993); Germany, Poland, Russia, ?USA, Ukraine.
Genus Tangarilda Gründel, 2010 Fig. 1B.
Type species: Melania turritella Dunker, 1846 (= Cerithium subturritella Orbigny, 1850 nom. nov.), original designation; Hettangian, Germany.
Included species: Cerithium subturritella d'Orbigny, 1850, Hettangian; Tangarilda sp. sensu Gründel 2010, Hettangian.
Emended diagnosis.—A genus of the Mathildidae with three primary spiral ribs. The middle and sometimes also the abapical spiral rib are stronger than the others (whorls octagonal in transverse section). The growth lines are asymmetrically opisthocyrt with the backmost point between the adapical and the middle spiral rib. The lowermost part of the growth lines is strongly opisthocline. Secondary spiral ribs may be developed.
Stratigraphic and geographic range.—Hettangian (and Sinemurian?); Germany.
Genus Jurilda Gründel, 1973 Fig. 1C.
Type species: Mathilda (Jurilda) crasova Gründel, 1973 (= subjective junior synonym of Promathilda (Teretrina) concava Walther, 1951); original designation: Bajocian to Bathonian, Poland.
Included Jurassic species: The genus is present with numerous Jurassic species. Some examples are: Promathildia angularis lineata Jamničenko, 1987, Toarcian—Aalenian; Mathildawonwalensis Schröder, 1995, Valanginian; Promathildia conoidea Gründel, 1997, Bajocian; Promathildia naricata Gründel, 1997, Bathonian—Callovian; Promathildia pommerana Gründel, 1997, late Bathonian—early Callovian.
Emended diagnosis.—Shell slender to moderately broad; protoconch transaxial to almost coaxial, smooth or with radial folds; teleoconch with two primary spiral ribs; abapical rib may be strong, keel-like; few secondary spiral ribs can occur; spiral ribs intersected by strengthened growth lines; intersections are not or only slightly nodular; strengthened growth lines prosocline, straight to weakly prosocyrt between adapical suture and abapical spiral rib and nearly orthocline from the abapical spiral rib to the abapical suture; backmost point of growth lines on abapical primary spiral rib; faint micro-ornament of spiral striae present in some species; base more or less convex; aperture oval, rounded, sometimes (always?) with anterior siphonal canal.
Stratigraphic and geographic range.—Possible Triassic representatives of Jurilda are still doubtful and may belong to the genus Teretrina Cossmann, 1912 (AN and JG personal observations). The type species, Turritella bolina Münster, 1841, from the Late Triassic Cassian Formation has growth lines which are distinctly opisthocyrt between the adapical suture and the abapical spiral rib, i.e., their cenit is situated above the abapical primary spiral rib. However, other species which have been described as Promathildia species by Bandel (1995) have a course of the growth lines including axial ornaments similar to that of the Jurassic species. The first certain members of Jurilda are of Hettangian age. For instance Chapuis and Dewalque (1854), Terquem and Piette (1868), and Piette (1855) reported species which according to their descriptions and illustrations should be classified to Jurilda. Jurilda is at least present until the Early Cretaceous (Schröder 1995; Kaim2004). The last occurrence of the genus is unclear. The genus is known from Germany, Poland, Italy, Ukraine.
Fig. 1.
Type species and examples for Jurassic genera of the family Mathildididae. A. Mathilda angulata (Gründel, 1997), erratic boulder from Hohendorf near Wolgast 3/96/3, Germany, Callovian; from Gründel (1997: pl. 5: 73). B. Tangarilda subturritella (d'Orbigny, 1850), Kanonenberg near Halberstadt, Germany, Hettangian; from Gründel (2010: pl. 3: 3). C. Jurilda concava (Walther, 1951), borehole Kłęby (formerly Klemmen) 1/37, Poland, Bathonian; from Gründel (1997: pl. 1: 1). D. Tricarilda plana (Gründel, 1973), bore Kłęby (formerly Klemmen) 1/37, Poland, Callovian; from Gründel (1997: pl. 3: 41). E, F. The group of Turritella binaria (Jurilda or Tricarilda). These species were also originally included in Promathildia; see also Fig. 4. E. Alaria clathrata Terquem and Jourdy, 1871, Les Clapes, Bathonian; from Terquem and Jourdy (1871: pl. 4: 7). F. Turritella binaria Hébert and Eudes-Deslongchamps, 1860, La Motte Bourbon, early Callovian, Bayerische Staatssammlung für Paläontologie BSPG 2012 I 22.
Genus Tricarilda Gründel, 1973 Fig. 1D.
Type species: Mathilda (Tricarilda) plana Gründel, 1973, original designation; Callovian; north-western Poland.
Included Jurassic species: The genus is present with numerous Jurassic species. Some examples are: Tricarilda krumbecki (Kuhn, 1935), Aalenian; Tricarilda tareka Gründel, 1997, Bajocian, ?Bathonian; Tricarilda toddi Gründel, Kaim, Nützel, and Little, 2011, Pliensbachian; Tricarilda striatissima Gründel, 1999b, Bathonian—Callovian; Bathraspira sp. sensu Kollmann 1982, Early Cretaceous; Tricarilda sp. sensu Gründel 2003b, Early Sinemurian; Mathilda schmidti (Walther, 1951) sensu Kaim (2004), Bajocian—Early Cretaceous(?); Tricarilda sp. sensu Gründel 2007c, late Sinemurian.
Emended diagnosis.—Similar to Jurilda but the teleoconch immediately with three primary spiral ribs; middle one is strongest, and can be keel-like; additional secondary spiral ribs may lack or are abundant; micro-ornament of spiral striae either absent or weak.
Stratigraphic and geographic range.—The oldest certain member is Tricarilda sp. from the early Sinemurian as reported byGründel (2003a). Possible Hettangian species which probably belong to the Jurilda—Tricarilda-group are uncertain because their early ontogeny is insufficiently known. The last certain occurrence of Tricarilda is Early Cretaceous (Mathilda schmidti (Walther, 1951) sensu Kaim 2004, Bathraspira sp. sensu Kollmann 1982). However, it is not clear when the genus became extinct. The genus is known from Germany, England, France, Italy, Poland, Russia, Ukraine, New Zealand.
Genus uncertain “Turritella” binaria Hébert and Eudes-Deslongchamps, 1860 Fig. 1E, F.
Similar species: Alaria clathrata Terquem and Jourdy, 1871, Bathonian; ?Carinathilda? sp. sensu Kaim 2004, late Bajocian.
Description.—Shell moderately slender, large; ornament dominated by strong spiral ribs; axial ornament consist of reinforced growth lines only; whorls are keeled at a spiral rib; base convex, not demarcated from whorl face, ornamented with some spiral ribs; protoconch and early teleoconch unknown.
Remarks.—It is unclear whether the “Turritella” binariagroup belongs to Jurilda or Tricarilda because the early whorls are unknown. Cossmann (1912) assigned it to the genus Teretrina. However, the Triassic type species has another growth line pattern which is opisthocyrt above the keel and it lacks a subsutural spiral rib. Mathilda binaria (Hébert and Eudes-Deslongchamps) sensu Andreae (1887) represents another species and belongs to the genus Angulathilda gen. nov. Turritella binaria and Alaria clathrata were originally included in the genus Promathildia when this genus was introduced (see below).
Stratigraphic and geographic range.—Late Bajocian?, Bathonian to Callovian; France, ?Poland.
Genus Gymnothilda Schröder, 1995 Fig. 2A.
Type species: Gymnothilda levata Schröder, 1995, original designation; Early Cretaceous (Valanginian); Wąwał, Poland.
Included species: Gymnothilda levata Schröder, 1995, Valanginian; Mathilda tomaszina Schröder, 1995, Valanginian; Gymnothilda dispiralis Gründel, 1997, late Bathonian—early Callovian; Gymnothilda torallolensis Kiel and Bandel, 2001, Campanian; Gymnothilda reesi Kaim, 2004, Valanginian.
Diagnosis.—Shell broad, conical; protoconch transaxial to slightly medioaxial, smooth or with axial folds; early teleoconch with one or two primary spiral ribs; whorls keeled at one of primary spiral ribs; base sharply demarcated from whorl face by edge; additional spiral ribs absent or only present on keel; axial ornament lacking or only weak on early teleoconch whorls or only developed on the keel; micro-ornament may be present.
Remarks.—In its present composition, Gymnothilda is rather heterogeneous. However, only a few species are included so that a subdivision is not warranted. Gymnothilda contains species with one or two primary spiral ribs and with or without micro-ornament. Kaim (2004) restricts the genus to Early Cretaceous species (Valanginian). The oldest species assigned to Gymnothilda is the Bathonian G. dispiralis Gründel, 1997 (late Bathonian to early Callovian). However, Kaim (2004: 134) doubted this generic assignment and stated that it probably represents a species of Promathildia, and that its reduced axial ornamentation derived independently. We consider this as a possible interpretation but leave the Middle Jurassic G. dispiralis in Gymnothilda until we know more about this genus.
Stratigraphic and geographic range.—Gymnothilda as understood here, has its first occurrence in the late Bathonian and ranges with G. torallolensis Kiel and Bandel, 2001 into the Late Cretaceous (Campanian). Gymnothilda pagodoidea Kiel, 2006 (Albian) belongs to Bathraspira (see below). It is also possible that the only known specimen of G. torallolensis represents a juvenile of Bathraspira. The genus is known from Germany, Poland.
Genus Bathraspira Cossmann, 1906 Fig. 2B, C.
Type species: Cerithium tectum Orbigny, 1842, original designation; Albian, France.
Included species: The protoconch is known only for Bathraspira pagodoidea (Kiel, 2006). All the other species of Bathraspira remain therefore uncertain.
Remarks.—Usually, Bathraspira was assigned to the caenogastropod familiy Procerithiidae (for example Cossmann 1906; Abbass 1973; Kiel 2006). Protoconch and early teleoconch whorls have been unknown until Kiel (2006) described Gymnothilda pagodoidea from the Albian of Madagascar. This species unites a mature teleoconch which is typical for Bathraspira and a protoconch as well as early teleoconch whorls which are typical for Gymnothilda. If the juvenile specimen of this species illustrated byKiel (2006: fig. 8/1) was found alone, it would be certainly assigned to Gymnothilda. Steffen Kiel (personal communication 2010) also agreed that “Gymnothilda” pagodoidea belongs to Bathraspira. It is yet unknown whether this ontogenetic change is also present in other Bathraspira species. In any case, Bathraspira pagodoidea (Kiel, 2006) is certainly a member of the Mathildidae. Bathraspira sp. sensu Kollmann 1982 (late Early Cretaceous) represents a juvenile specimen consisting of a protoconch and two teleoconch whorls; it shows the characters of Tricarilda.
Stratigraphic and geographic range.—Bathraspira is known only from the Cretaceous; France, England, Madagascar.
Fig. 2.
Type species and examples for Cretaceous genera of the family Mathildidae. A. Gymnothilda levata Schröder, 1995, Wąwał, Valanginian; from Kaim (2004: fig. 113A1). B, C. Bathraspira pagodoidea (Kiel, 2006), Mahajanga Basin/Madagascar, Albian; from Kiel (2006: figs. 8.1, 8.2). Juvenile (B) and adult (C) specimens.
Genus Carinathilda Gründel, 1997 Fig. 3A.
Type species: Carinathilda carinata Gründel, 1997, original designation; Middle Jurassic; NW Poland.
Included species: Carinathilda carinata Gründel, 1997, Bathonian; Carinathilda calteriana Gründel, 1997, Callovian.
Emended diagnosis.—Protoconch (always?) coaxial; shell moderately broad with two primary spiral ribs and keeled whorls; whorl outline oblique and straight between keel and abapical suture, weakly convex above the keel; base strongly and evenly convex without demarcation to whorl face; weaker secondary spiral ribs and reinforced growth lines form a fine reticulate pattern; a distinct micro-ornament of numerous fine spiral threads is present.
Remarks.—Differences to Angulathilda are discussed below. Jurilda has a more slender teleoconch and the keel is less pronounced. Moreover, Jurilda lacks a distinct micro-ornament. Stratigraphic and geographic range.—Bathonian to Callovian; Germany, Poland.
Fig. 3.
Type species and examples for Jurassic genera of the family Mathildididae. A. Carinathilda carinata Gründel, 1997, bore Kłęby (formerly Klemmen) 1/37, Poland, Bathonian; from Gründel (1997: pl. 7: 98). B. Angulathilda calloviensis (Gründel, 1997), erratic boulder from Hohendorf near Wolgast 3/96/3, Germany, Callovian; from Gründel (1997: pl. 7: 98, 101).Whole specimen (B1), detail of the ornament (B2). C. Erratothilda erratica (Gründel, 1990), erratic boulder from Bauer-Wehrland, Germany, Callovian; from Gründel (1997: pl. 7: 104, 105). Whole specimen (C1), detail showing ornament (C2).
Genus Angulathilda nov. Fig. 3B.
Etymology: From Latin angulatus, angulated; because of the basal angulated edge; the ending -thilda refers to the ending of the related genus Mathilda.
Type species: Carinathilda calloviensis Gründel, 1997 from glacial erratic boulder, Hohendorf/Mecklenburg-Vorpommern, NE Germany; Callovian.
Included species: ?Mathilda binaria Hébert and Eudes-Deslongchamps, 1860 sensu Andreae 1887, Oxfordian; Purpurina (Pseudalaria) guerreri (Hébert and Eudes-Deslongchamps, 1860) sensu Couffon 1919; Teretrinamicrostriata Schröder, 1995, Oxfordian; Teretrina tectispira Schröder, 1995, Oxfordian; Carinathilda calloviensis Gründel, 1997, Callovian; Carinathilda sp., cf. calloviensis Gründel, 1997, late Bathonian— early Callovian; Carinathilda bathoniensis Gründel, 1999b, early Bathonian; Carinathilda? naricatoidea Kaim, 2004, Middle Bathonian; Carinathilda saulae Kaim, 2004, Valanginian; Carinathilda squiresi Kaim, 2004, Valanginian; Carinathilda sp. sensu Gründel 2005a, Callovian; ?Carinathilda procera Gründel, 2006, late Bathonian; Carinathilda bandeli Kiel, 2006, Albian; Carinathilda cf. microstriata (Schröder) sensu Kiel 2006, Albian; ?Carinathilda parviruga Kiel, 2006, Albian.
Diagnosis.—Protoconchmedioto coaxial, smooth orwith radial wrinkles; shell moderately broad with two primary spiral ribs and strongly keeled whorl face; whorl face somewhat concave below and above keel; numerous fine axial ribs (or strong growth lines); base slightly to moderately convex; whorls face joins base at distinct angulation with strong spiral rib; micro-ornament of numerous fine spiral threads present.
Remarks.—Mathilda binaria Hébert and Eudes-Deslongchamps, 1860 sensu Andreae (1887) and Carinathilda procera Gründel, 2006 do not show any micro-ornament (in the latter, this could be due to preservation) and are therefore placed only tentatively in Angulathilda. The Cretaceous Carinathilda parviruga Kiel, 2006 has a distinct umbilicus which is not present in other species of this genus. Several species which were described before SEM studies were possible cannot neither be included nor excluded with certainty because the diagnostic relevant presence of a micro-ornament was not tested.
In contrast to Angulathilda, Carinathilda has a strongly convex base which is not demarcated from the whorl face by an edge; moreover the whorl face is slightly convex below the keel in Carinathilda. Erratothilda has three or more primary spiral ribs.
Stratigraphic and geographic range.—Bathonian to Early Cretaceous; Germany, ?France, Poland, Russia.
Genus Erratothilda Gründel, 1997 Fig. 3C.
Type species: Eucycloidea erratica Gründel, 1990, original designation; glacial erratic boulder from Bauer-Wehrland/Mecklenburg-Vorpommern, NE Germany, Callovian.
Included species: Eucycloidea erratica Gründel, 1990, Callovian; Erratothilda dziki Kaim, 2004, Valanginian; Erratothilda krawczynski Kaim, 2004, Valanginian; ?Erratothilda wascherae Gründel, 2006, Late Bathonian.
Emended diagnosis.—Shell and ornament basically as in Angulathilda. However, Erratothilda has three or more primary spiral ribs. Erratothilda has a pronounced micro-ornament.
Remarks.—The characteristic micro-ornament has not been shown for Erratothilda wascherae Gründel, 2006 which comes from a locality at which the preservation is not sufficient to show such fine details.
Stratigraphic and geographic range.—Questionable Bathonian, certainly from the Callovian to Early Cretaceous; Germany, ?France.
Family Gordenellidae Gründel, 2000
Remarks.—In our opinion, the diagnostic differences between Mathildidae and Gordenellidae as outlined by Gründel (2000) remain valid despite Guzhov's (2007) doubts. Gordenellids differ from mathildids in the rather large size, slender to very slender shape, high number of whorls, early teleoconch whorls with mathildid ornament (three primary spiral ribs, middle and abapical spiral strongest and angulating whorl profile, numerous opisthocyrt axial ribs), and change of the ornament on mature teleoconch whorls (sometimes complete reduction) (see below).
Genus Promathildia Andreae, 1887 (Synonym: Clathrobaculus Cossmann, 1912)
Figs. 4A–C, 5A–C.
Type species: Mathilda janeti Cossmann, 1885, here designated; Bathonian; France.
Included species: There are certainly more than the here listed species, which belong to the genus Promathildia. However, descriptions and illustrations are commonly insufficient for a reasonable assignment. For the majority of the species listed below, the protoconch is unknown so that the placement of these species is also somewhat uncertain (the transaxial, strongly emerging protoconch is diagnostic). Included species: Cerithium amoenum Eudes-Deslongchamps, 1843, Bajocian; Cerithium ziczac Eudes-Deslongchamps, 1843 (= type species of Clathrobaculus), Pliensbachian; Turritella eucycla Hébert and Eudes-Deslongchamps, 1860, Callovian; Turritella subulatissima Hébert and EudesDeslongchamps, 1860, Callovian; Clathrobaculus fistulosus (Stoliczka, 1861), Sinemurian; Cerithium collenoti Martin, 1862, Sinemurian; Cerithium sinemuriensis Martin, 1862, Sinemurian; Mathilda janeti Cossmann, 1885, Bathonian; Rigauxia gracilis Dareste de la Chavanne, 1912, Hettangian; Promathildia (Clathrobaculus) doncieuxi Cossmann, 1913, Oxfordian; Tricarilda plana with aberrant protoconch sensu Gründel 1997, Callovian; Clathrobaculus sp., cf. eucyclus Hébert and EudesDeslongchamps, 1860 sensu Gründel 2000, Callovian; ?Clathrobaculus? humberti Martin sensuGründel 2003b, Hettangian; Clathrobaculus sp. 1 sensu Kaim 2004, Valanginian; ?Clathrobaculus sp. 2 sensu Kaim 2004, Callovian; Clathrobaculus sp. 3 sensu Kaim 2004, Bathonian; Clathrobaculus demissus Gründel, 2006, late Bathonian; ?Clathrobaculus medidilatatus Guzhov, 2007, Oxfordian.
Spelling.—In the literature, both spelling variants, Promathildia and Promathilda are commonly used. Andreae (1887) introduced the genus as Promathildia. It was emendated to Promathilda because this name refers to the progenitor of the modern genus Mathilda Semper, 1865 (Bieler 1995). However, Phillippe Bouchet (personal communication 2010) pointed out to us that the emendation Mathildia dates from Bosquet (1869): “This suggests that the spelling Promathildia is not an original incorrect spelling but that Andreae voluntarily used the emendation Mathildia combinedwith the prefix Pro-.”
Emended diagnosis.—Shell slender, relatively large, with many whorls; protoconch heterostrophic, transaxial, distinctly emerged, detached or almost detached from initial teleoconch whorl; teleoconch whorls with 3 (4) primary spiral ribs, convex with distinctly deepened suture, angulated at two of the primary spiral ribs (octagonal whorl outline) or with one of the primary spiral ribs as keel. Numerous fine axial ribs or strong growth lines; teleoconch ornament does not change during ontogeny or changes are only minor.
Remarks.—Promathildia is now included in Gordenellidae because Mathilda janeti is here designated as type species of this genus and this species is a gordenellid. Andreae (1887) introduced the genus Promathildia in a work on Late Jurassic (Oxfordian) gastropods from Alsace (east France). It was introduced as follows (Andreae 1887: 23–24, translated from German): “The affiliation of certain Jurassic turritellid forms to the Recent genus Mathildia Semper was first recognized by Laube (1867) and again confirmed by Cossmann (1885) by the finding of inverse and perpendicularly situated embryonic whorls in Mathildia Janeti Coss. Anyhow, it seems conspicuous to us that the Jurassic mathildids (which could possibly be called Promathildia) exceed their living relatives so eminently in size. As far as I can overview the Jurassic mathildids, they seem split into at least 2 morpho-groups. The more slender ones with pronounced reticulate ornament group around Mathildia Janeti Coss., M. reticularis Piette etc. by almost lacking a siphonal outlet of the aperture. In the others, the spiral keels exceed the fine transverse ribs by far and its type is formed by M. binaria. These are broader and have a rather wide but flat anterior outlet of the aperture. According to this aperture shape, they resemble Messalia and Mesostoma. The latter Tertiary genus has also the same ornament. I am retaining these forms in Mathildia because I found one of the most important characters, the inverse embryonic end, in a good specimen from the Pfirt. Species related to M. binaria have commonly been assigned to Alaria as is the case in the previously mentioned species Alaria clathrata Terq. & Jourd. and Pterocera Cassiope d'Orbigny from the Oxfordian of Neuvizy, which was assigned to Alaria by Piette”. This citation shows that Promathildia was originally meant as a kind of chronotaxon encompassing the Jurassic mathildids which are allegedly larger than living members of Mathilda (size is the only diagnostic feature mentioned by Andreae 1887). It is clear that Andreae (1887) did not designate a type species for Promathildia and did not provide a sufficient diagnosis. He distinguished two morpho-groups within Promathildia but this is irrelevant for nomenclature because he did not name these groups. The designation of M. binaria as “type” for one of the unnamed subdivisions of Promathildia does not represent the designation of a type species because it relates not to a name bearing group. This is also true for Koken's (1889: 458–459) treatment of Promathildia. This author repeated Andreae's (1887) text verbally and as Andreae (1887), he did not name any of the two proposed subgroups of Promathildia. Andreae (1887) mentioned five nominate Jurassic species as members of Promathildia and one of those originally included taxa can be designated as type species:
— Mathilda janeti Cossmann, 1885,
— Mathilda reticularis (Piette, 1855),
— Alaria clathrata Terquem and Jourdy, 1871,
— Turritella binaria Hébert and Eudes-Deslongchamps, 1860
— Pterocera cassiope Orbigny, 1850.
Koken (1889) used the genus Promathildia for Triassic mathildoids including for “Cerithium bisertum” from the Cassian Formation. Kittl (1894) was the first to formally assign species (from the Triassic Cassian Formation) to the genus Promathildia in binominal form (Nützel and Erwin 2004). Cossmann (1912) designated Cerithium bisertum Münster, 1841 from the Late Triassic Cassian Formation as type species of Promathildia. However, this designation is invalid because Cerithium bisertum has not been originally included by Andreae (1887) (ICZN article 67.6, 69.1, 69.2.2). Moreover, this species differs significantly from the Jurassic species that were mentioned by Andreae (1887) as examples for Promathildia. Thus this designation is in conflict with Andreae's (1887) intention. In the following, we will discuss each of the originally included species as possible type species for Promathildia:
— Mathilda janeti Cossmann, 1885 (Fig. 4A–C) represents probably a species of the genus Clathrobaculus Cossmann, 1912 according to its overall morphology. Cossmann (1885: pl. 14: 20, 21) reported a heterostrophic protoconch of the Mathilda-type for M. janeti (see Fig. 4A herein); therefore this species is certainly a mathildoid. Obviously, Cossmann (1885) had only juvenile specimens at hand. The heterostrophic, transaxial protoconch and the slender shell of M. janeti would support an assignment to Clathrobaculus.
— Mathilda reticularis (Piette, 1855) (Fig. 4D, E) was insufficiently described by Piette (1855) and no illustration was given. It was described and illustrated by Cossmann (1885). One specimen (Cossmann 1885: pl. 17: 34; see Fig. 4E herein) is from the Piette's (1855) collection and comes from the type locality (Rumigny, Bathonian) according to Cossmann. We designate this specimen as lectotype of Mathilda reticularis. It is a teleoconch fragment which is 13.6 mm high. The whorl face is ornamented with four spiral ribs, two of which are more pronounced on the earliest preserved whorls. Protoconch, primary spirals on the early teleoconch, and aperture are unknown. Due to this incomplete preservation, it is not suitable as type species of Promathildia.
— Alaria clathrata Terquem and Jourdy, 1871 (Bathonian; Fig. 1E) and Turritella binaria Hébert and Eudes-Deslongchamps, 1860 (Callovian; Fig. 1F) closely resemble each other and both species are congeneric (see above). Both were repeatedly assigned to the genus Teretrina Cossmann, 1912. Teretrina has a Triassic type species which differs significantly from both Jurassic species (AN and JG own observations) so that this generic assignment can be refuted. Alaria clathrata and Turritella binaria occupy a certain place within the Jurassic Mathildoidea (see below). The teleoconch of both species is relatively well known. However, protoconch and early teleoconch including primary spiral ribs have not been described or illustrated to this point. If one of these species would be chosen as type species of Promathildia, these important characters would remain unknown and therefore the status the genus would be unclear.
— Pterocera cassiope Orbigny, 1850 (Fig. 4F) (= nom. nov. pro Rostellaria bispinosa Phillips, 1829) (illustrated by Phillips 1829: pl. 4: 32 and Piette 1864–91: pl. 35: 1–4, non pl. 1: 7, which probably is a Dicroloma or Bicorempterus species and insufficiently known). This species is not suitable as type species of Promathildia because many important characters are unknown and the species probably represents the caenogastropod family Aporrhaidae.
Andreae (1887) identified some of his Oxfordian specimens as Mathilda binaria (Hébert and Eudes-Deslongchamps, 1860), a species which was originally described from the Callovian of France. However, this is certainly a misidentification—there are strong differences in shape and ornament. For instance, Andreae's (1887: pl. 1C: 1–3) illustrations show a hardly convex base bordered by a strong spiral rib so that the basal edge is angular. It probably represents an undescribed species of the genus Angulathilda. A description of a new species is not warranted yet because of the insufficient knowledge of this species. It is very likely that it represents a mathildid because Andreae (1887: 24) mentioned that the protoconch is heterostrophic.
In conclusion, of all species which were mentioned by Andreae (1887) when introducing the genus Promathildia, only Mathilda janeti is sufficiently known to characterize the genus. Therefore, we designate Mathilda janeti Cossmann, 1885 as a type species of Promathildia Andreae (1887). This species is most probably congeneric with the type species of the genus Clathrobaculus Cossmann, 1912 (Fig. 5A) and therefore Clathrobaculus is a junior synonym of Promathildia. Promathildia janeti is slender, with numerous convex whorls separated by deep suture and has an ornament of two strong spiral ribs; the protoconch is relatively large and transaxial. These characters are also typical of Clathrobaculus (Cossmann 1912; Guzhov 2007). The relatively small size of the originals of Mathilda janeti as illustrated by Cossmann (1885) probably indicates that he had only juveniles at hand. Our designation of a type species from those species which were originally included by Andreae (1887) changes the previous concept (e.g., Bandel 1995; Gründel 1997; Kaim 2004) and the genus should now be included in the family Gordenellidae Gründel, 2000 (see discussion of the Gordenellidae below); this group had its greatest diversity in the Jurassic.
The protoconch is known for the following species of Promathildia: Mathilda janeti Cossmann, 1885 (Bathonian), Tricarilda plana Gründel, 1973 with aberrant protoconch sensu Gründel 1997 (Callovian), Clathrobaculus sp. 3 sensu Kaim (2004) (Bathonian), and Clathrobaculus demissus Gründel, 2006 (Bathonian). All other species listed above have a teleoconch morphology which agrees with the diagnosis of Promathildia as given above.
Haas (1953) described several species from the Late Triassic and the transition to the Early Jurassic of Peru which closely resemble Promathildia. He assigned some of them to Clathrobaculus (see also Guzhov 2007), e.g., Promathildia (Teretrina) bolinoides Haas, 1953, Promathildia (Teretrina) aculeata Haas, 1953, and Promathildia (Clathrobaculus) subulata Haas, 1953. For some of these species Haas (1953) could report a heterostrophic protoconch. However, these protoconchs cannot be evaluated from the illustrations provided by Haas (1953). According to their teleoconchmorphology, it is very likely that these species belong to Promathildia or are closely related to this genus. Promathildia seems to be absent in the Late Triassic Cassian Formation; none of the species reported by Bandel (1995) seems to represent this genus.
Gordenella Gründel, 1990 differs from Promathildia in having straight to concave sides of mature teleoconch whorls. Moreover, in Gordenella the middle primary spiral is moving toward the abapical suture during ontogeny; at the same time, the primary spiral rib becomes weaker (in some cases it fades completely). Gordenella also differs in showing an ontogenetic weakening of the axial ribs.
Stratigraphic and geographic range.—The stratigraphic occurrence of Promathildia can only be given preliminarily, because many species which probably belong to this genus are insufficiently known. The oldest certain species is of Hettangian age (Cerithium collenoti Martin, 1862). The genus is probably as old as Late Triassic. The last representative is of Early Cretaceous age (Clathrobaculus sp. 1 sensu Kaim 2004). The genus is known from Germany, Austria, France, Poland, ?Russia.
Fig. 4.
Jurassic species originally included in Promathildia (family Gordenelllidae) (see also Fig. 1E, F). A–C. Mathilda janeti Cossmann, 1885 is designated as type species of Promathildia herein; Hérouvillette, France, late Bathonian. A. From Cossmann (1885: pl. 14: 20, 21), with protoconch in lateral (A1) and axial (A2) views. B. Last whorl with aperture; from Cossmann (1885: pl. 14: 19). C. Mathilda janeti Cossmann, 1885; from Cossmann (1885: pl. 14: 18 ). D. Mathilda reticularis (Piette, 1855), Le Wast, late Bathonian; from Cossmann (1885: pl. 8: 9). E. Mathilda reticularis (Piette, 1855), Rumigny, France, late Bathonian; from Cossmann (1885: pl. 17: 34), lectotype. F. Pterocera cassiope d'Orbigny, 1850, France, Oxfordian; from Piette (1864–91: pl. 35: 4).
Fig 5.
Type species and examples for the Jurassic genus Promathildia (family Gordenellidae) and protoconch of Falsoebala for comparison. A. Promathildia ziczac (Eudes-Deslongchamps, 1842), type species of Clathrobaculus, France, Early Jurassic; from Eudes-Deslongchamps (1843: pl. 11: 8, 9). Whole specimen (A1), last whorl enlarged (A2). B. Promathildia sp., cf. eucycla (Hébert and Eudes-Deslongchamps, 1860), erratic boulder from Vorpommern (NE Germany), Callovian; from Gründel (2000: pl. 1: 2). C. Promathildia sp., bore Usedom 3/63 (NE Germany), Late Bathonian, protoconch; from Gründel (1997: pl. 4: 48). D. Falsoebala compacta Gründel, 1998, bore Kłęby (formerly Klemmen) 1/37, Poland, Callovian, protoconch.
Genus Gordenella Gründel, 1990 Fig. 6A, B.
Type species: Cerithium? pommeranum Schmidt, 1905, original designation; Oxfordian; Poland.
Included species: Turritella fahrenkohli Rouillier, 1848, Callovian—Oxfordian; Turritella krantzi Rouillier, 1848, Oxfordian; Turritella schlumbergi Eudes-Deslongchamps, 1866, Bajocian; Cerithium? Pommeranum Schmidt, 1905, Oxfordian; ?Procerithium (Cosmocerithium) kunceviense Gerasimov, 1992, Tithonian; Gordenella wehrlandia Gründel, 2000; Gordenella sp., cf. wehrlandia Gründel, 2000 sensu Gründel 2003a, Bathonian; Clathrobaculus inconstantiplicatus Guzhov, 2007, late Callovian?, Oxfordian; ?Gordenella? sp. sensu Schubert et al. 2008, Pliensbachian. According to Guzhov (2007), Turritella sauvagei Buvignier, 1852, Turritella divisa Ilovaisky, 1904, Turritella complanata Brösamlen, 1909, and Promathildia bigoti Cossmann, 1913 are synonyms of Turritella fahrenkohli; Turritella bicostata Ilovaisky, 1904 and probably also Turritella praecursor Andreae, 1887 are synonyms of Gordenella krantzi.
Emended diagnosis.—Shell slender, large, with many whorls; protoconch heterostrophic, transaxial, distinctly emerged, detached or almost detached from initial teleoconch whorl; early teleoconch whorls with two strong and often several weaker spiral ribs as well as numerous opisthocyrt axial ribs; strong abapical spiral rib moves down towards the abapical suture until it is positioned slightly above the abapical suture; this spiral becomes stronger during ontogeny; at the same time, strong adapical spiral is weakening and may fade entirely; below adapical suture one or two spiral ribs become increasingly stronger; whorl face straight to concave (the latter inmost species); axial ribs are reduced to strong growth lines on the last whorls of adult specimens.
Remarks.—The name Clathrobaculus, as cited in older literature, is replaced in the following discussion with Promathildia according to its new definition. Guzhov (2007) described the characteristic type of protoconch for several species representing Gordenella. The same type is also present in Promathildia. When Gründel (2000) introduced the family Gordenellidae, he considered Clathrobaculus as being closely related to Gordenella Gründel, 1990. However, he decided that the separation line between Mathildidae and Gordenellidae runs between both genera because Clathrobaculus lacks an important character of the Gordenellidae, namely the conspicuous ontogenetic change of the teleoconch sculpture which can even result in a complete reduction of the ornament in mature teleoconch whorls. Clathrobaculus and Gordenella share the relatively large size (for mathildoids), the very slender multiwhorled shell and especially the transaxial protoconch which is widely elevated and not covered by the initial teleoconch whorl. Therefore, Clathrobaculus (= Promathildia) is assigned to Gordenellidae. All genera of the Gordenellidae have an early ontogenetic “Clathrobaculus”-stage, which has also been identified by Guzhov (2007).
Guzhov (2007) assumed a fluent transition from Clathrobaculus sensu stricto in his sense (= Promathildia herein) and species of Gordenella sensu Gründel (2000). Therefore, he considered Gordenella to represent a synonym of Clathrobaculus. Clathrobaculus medidilatatus Guzhov, 2007 has a relatively weak ontogenetic change of the teleoconch ornament i.e., rounded whorl flanks, minor displacement of the strongest spiral rib in an abapical direction, weakening of the axial ornament associated with an increase in the number of axial ribs per whorl. Even if this species is included in the genus Clathrobaculus, there are still pronounced differences between Clathrobaculus sensu stricto = group 1 according to Guzhov (2007) and groups 2+3 as defined by Guzhov (2007) (= Gordenella sensu Gründel 2000): (i) Clathrobaculus has convex and keeled/angulated teleoconch whorls and its teleoconch ornament does not change during ontogeny (or only minor changes occur); (ii) groups 2+3 as defined by Guzhov (= Gordenella sensu Gründel 2000) has mostly a concave whorl face (or it is straight) and a pronounced ontogenetic change of the teleoconch ornament which was described in detail by Gründel (2000). The morphological differences between groups 1 and 2+3 sensu Guzhov are much more pronounced than the differences between groups 2 and 3 (subgenera of Gordenella?). Therefore we consider Gordenella to represent a valid genus, separate from Clathrobaculus (= Promathildia).
Stratigraphic and geographic range.—Certain Gordenellaspecies with known protoconch and first teleoconch whorls including an early Promathildia-like stage are known from the Callovian and Oxfordian. Specimens with typical Gordenella-like mature teleoconch whorls were reported from the Bathonian by Gründel (2000) and from the Bajocian by Eudes-Deslongchamps (1866). It is very likely that this material represents Gordenella. The generic assignment of Gordenella? sp. from the Late Pliensbachian as reported by Schubert et al. (2008) remains doubtful. Procerithium (Cosmocerithium) kunceviciense Gerasimov, 1992 is also insufficiently known. Thus, Gordenella ranges from the Bajocian to the Oxfordian according to the current state of knowledge. The genus is known from Germany, France, Luxembourg, Poland, Russia.
Fig. 6.
Type species and examples for Jurassic genera of the family Gordenellidae. A, B. Gordenella pommerana (Schmidt, 1905), Kłęby (formerly Klemmen), Poland, late Oxfordian. A. From Gründel (2000: pl. 1: 8). B. From Gründel (2000: pl. 1: 11). C. Turritelloidea opalina (Quenstedt, 1852), Mistelgau, Germany, late Toarcian, see also Gründel (2005: figs. 2/1, 3). D. New genus, new species to be described elsewhere, Buttenheim, Germany, late Pliensbachian; whole specimen (D1), early whorls (D2).
Genus Turritelloidea Walther, 1951
(= Turrithilda Schröder, 1995; = ?Costacolpus Marwick, 1966) Fig. 6C.
Type species: Turritella opalina Quenstedt, 1852, original designation; Toarcian to Aalenian; South Germany.
Included species: Turritella minuta Koch and Dunker, 1837, Kimmeridgian—Tithonian; Turritella opalina Quenstedt, 1852, late Toarcian— early Aalenian; Cerithium? decipiens Hébert and Eudes-Deslongchamps, 1860, Callovian; ?Turritella anomala Moore, 1867, Pliensbachian; ?Turritella (Mathilda) abbas Hudleston, 1892, Toarcian— Aalenian; Turritella (Mathilda) strangulata Hudleston, 1892, Aalenian; ?Turritella solitaria Wilckens, 1922, Late Cretaceous; ?Promathildia turritella (Dunker, 1847) sensu Meier and Meiers 1988, Hettangian; gen. nov. terquemi (Bistram, 1903)? sensu Gründel 2003b, Hettangian; ?Turritelloidea sp. sensu Schubert et al. 2008, Pliensbachian.
Diagnosis.—Shell median-sized to large and highly conical. The heterostrophic protoconch of the Mathilda-type is nearly coaxial. On the first teleoconch whorl two strong keel-like spiral ribs and numerous axial ribs are developed. The lastwhorls have 6–7 spiral ribs of almost the same strength. In this part of the shell, the ribs are very broad (broader than the spiral furrows between them). The axial ribs become also broader and at the same time weaker. The ornament of the last whorls of adults consists only of broad spiral ribs (the base included).
Remarks.—The protoconch is only known for the type species. Hudleston (1892: 230) made the following remark for T.? abbas: “Indications of a sinistral apex have been observed on one specimen”. However, T.? abbas lacks the broadened, band-like spiral ribs and therefore is placed in Turritelloidea only tentatively (see also Gründel et al. 2011). The protoconch and the early teleoconch whorls of most of the species listed above are unknown and therefore, the generic assignment of these species is not beyond doubt. These species are placed in Turritelloidea because their mature teleoconch resembles that of the type species. The protoconch is also unknown for the type species of the genus Costacolpus Marwick, 1966 (Turritella solitaria Wilckens, 1922, Late Cretaceous). Its early teleoconch whorls have an ornament of axial and spiral ribs whereas the mature whorls have exclusively spiral ribs. The spiral ribs become very broad and are separated from each other by narrow furrows. The base has sometimes varix-like thickenings. Costacolpus solitaria closely resembles Turritelloidea opalina in general shape and ornament. Thus, it seems to be likely that Costacolpus represents a junior synonym of Turritelloidea.
In Fig. 6D a yet undescribed genus close to Turritelloidea is illustrated. It is from the Late Pliensbachian of Germany and will be described in the near future in the frame of a larger monograph. Because this genus is important for this work, we give a preliminary description herein. The shell is high-spired with numerous whorls. The early teleoconch whorls are ornamented with few, widely spaced, strong axial ribs. The earliest preserved teleoconch whorls show two median spiral ribs which somewhat angulate the whorl profile. In addition a weaker subsutural spiral is present. The intersections of axial and spiral ribs are nodular in early whorls. The position of the primary spiral ribs remains approximately stable during ontogeny. The spiral and axial ribs become weaker during ontogeny and intersections are not nodular any longer. Numerous additional spiral striae are added on mature teleoconch whorls and axial ornament consists of numerous densely spaced strengthened growth lines. The base is flat and is ornamented with narrow spiral ribs and broader furrows. The protoconch is unknown.
This yet undescribed new genus resembles Turritelloidea. However, Turritelloidea has broad spiral ribs separated by narrow furrows on mature teleoconch whorls. The type species of Gordenella (Fig. 6A, B) has a straight whorl profile; its mature teleoconch whorls does not show numerous spiral striae. The relatively large size, the high number of whorls and the suppression of axial ribs during ontogeny suggest that the new genus belongs to Gordenellidae.
Stratigraphic and geographic range.—Turritelloidea is certainly as old as Late Toarcian. It is likely that the genus ranges from the Hettangian to the Bajocian and even to the Late Jurassic or to the Late Cretaceous (e.g., T. minuta from the latest Jurassic and Costatrochus solitaria from the Late Cretaceous). The genus is known from Germany, England, France, ?Luxembourg.
Fig. 7.
Type species and examples for Triassic and Jurassic genera of the family Gordenellidae. A. Camponella pianozensis (Zardini, 1985), Cassian Formation, S Tyrol, Italy, Late Triassic; from Bandel (1995: pl. 8: 7). B. Proacirsa sp., cf. struvii (Lahusen, 1883), Dubki near Saratov, Russia, late Callovian; from Gründel (2005: pl. 5: 12, 16). Whole specimen (B1), protoconch (B2). C. Proacirsa laevigata (Eudes-Deslongchamps, 1843), erratic boulder from Bauer-Wehrland, Germany, Callovian; from Gründel (2000: pl. 1: 15). D. Schafbergia crenata (Stoliczka, 1861), Schafberg near St. Wolfgang, Austria, late Pliensbachian; from Szabó (2008: fig. 87B).
Genus Camponella Bandel, 1994 Fig. 7A.
Type species: Coelostylina pianozesis Zardini, 1985, original designation; Late Triassic; North Italy.
Included species: Only the type species is known.
Diagnosis.—“The small shell has a high spire with numerous flat-sided whorls and distinct suture. The protoconch is coiled sinistral and inclined with respect to the axis of the teleoconch. The first whorls (c. 5) of the juvenile teleoconch are covered with axial and spiral costae, of which the spiral ones are dominant. Later whorls are smooth or have indistinct spiral threads up to the edge of the base, while the base is covered by spiral carinae. The umbilicus is narrow and may form the opening to a hollow columella” (Bandel 1995: 18).
Remarks.—Camponella and Proacirsa share important characters: Protoconch morphology, ornament of the early teleoconch as well as reduction of this ornament during ontogeny, and broad spiral ribs on the base. Camponella differs from Proacirsa in being much smaller, in having fewer whorls and in having an umbilicus. Camponella is probably ancestral to Proacirsa.
Stratigraphic and geographic range.—Late Triassic; North Italy.
Genus Proacirsa Cossmann, 1912 Fig. 7B, C.
Type species.—Turritella inornata Terquem and Jourdy, 1871, original designation; Bathonian; France.
Included species: Cerithium laevigatum Eudes-Deslongchamps, 1843, Bajocian; Cerithium januale Trautschold, 1860, Pliensbachian (?); Chemnitzia dilatata Laube, 1867, Callovian (?); Turritella similis Moore, 1867, Pliensbachian; Turritella inornata Terquem and Jourdy, 1871, Bathonian; Chemnitzia struvii Lahusen, 1883, Callovian—Oxfordian; Cerithium semiornatum Greppin, 1888, Bathonian; Zygopleura (Anoptychia) bigoti Cossmann, 1913, Pliensbachian; Hudlestoniella lahuseni Gerasimov, 1962, Tithonian—Berriasian; Turrithilda zlotniki Kaim, 2004, Valanginian; Proacirsa sp., cf. struvii (Lahusen, 1883) sensu Gründel 2005a, Callovian.
Emended diagnosis.—The protoconch consists of about 1.5 whorls, is heterostrophic and almost coaxial. The early teleoconch has two or three spiral ribs; the adapical rib is distinctly weaker than the abapical spiral ribs. The spiral ribs are intersected by numerous axial ribs; the intersections are more or less nodular. After a few teleoconch whorls, the ornament fades. Only in some cases, remains of a spiral ornament are present on the last whorls. The base is moderately convex and is ornamented with broad spiral ribs.
Remarks.—The protoconch of a species belonging to Proacirsa was described by Gründel (2005b).
Stratigraphic and geographic range.—Pliensbachian to Valanginian, Early Cretaceous; Germany, England, France, Luxembourg, Switzerland, Poland, Russia.
Genus Schafbergia Gatto and Monari, 2010 Fig. 7D.
Type species: Chemnitzia crenata Stoliczka, 1861, original designation; Pliensbachian; Austria.
Included species: Chemnitzia crenata Stoliczka, 1861, Pliensbachian; ?Chemnitzia turgida Stoliczka, 1861, Sinemurian; Proacirsa (Schafbergia) zirettoensis Gatto andMonari, 2010, Sinemurian—Pliensbachian.
Emended diagnosis.—Shell shape similar to that of Proacirsa; protoconch unknown; early teleoconch whorls ornamented with several spiral ribs on the abapical whorl portion which are intersected by numerous axial ribs; intersections of axial and spiral ribs nodular; axial ribs reduced after a few whorls; mature teleoconch whorls with numerous weak spiral ribs which are somewhat more distinct in the abapical portion of the whorls; base with numerous somewhat broadened spiral ribs.
Remarks.—Proacirsa differs in having three spiral ribs which are distributed over the entire whorl face and in having fewer axial ribs in the early teleoconch whorls, in having rather broad spiral ribs on the base and a smoothwhorl face in mature teleoconch whorls.
Stratigraphic and geographic range.—Sinemurian to Pliensbachian, Early Jurassic; Italy, Austria, Hungary.
Family Tofanellidae Bandel, 1995
Remarks.—The Tofanellidae are characterized by coaxial protoconchs with a morphology that is considered to be diagnostic for the family (Bandel 2005: 19): “Its embryonic whorl is left coiled and immersed in the apex of the larval shell. The rounded whorls of the larval shell gradually change from left coiling to plane coiling and finally to dextral coiling.” However, even some Mathildidae have coaxial protoconchs (e.g., Erratothilda). It seems that the differentiation between Mathildidae and Tofanellidae is unclear in such cases. For instance, why is the protoconch of Mathilda bolina von Münster, 1841 sensu Bandel (1995: pl. 2: 2) of the mathildid type whereas that in pl. 11: 8 (Tofanella cancellata Bandel, 1995) allegedly tofanellid (see Fig. 8A, B)? And is Tricarilda octoangulata Gründel, 2006 then really a species of the Mathildidae or does it belong to Tofanella? Obviously these cases need further clarification.
The representatives of the Tofanellidae are generally small and have been overlooked in many studies. It seems to be likely that only a small part of the gone species diversity and distribution have been assessed. So far, the family has not been reported from the Late Cretaceous and Cenozoic. However, Bandel (2005) reported Recent representatives of the family. At least some tofanellid genera seem to be long ranging although all range dates most be treated with caution. Gründel (1998) subdivided the family Tofanellidae into the two subfamilies Tofanellinae Bandel, 1995 and Usedomellinae Gründel, 1998. Kaim (2004) refuted this subdivision and even Bandel (2005: 19) was sceptical: “Gründel (1998) suggested to split the taxon into the subfamilies Tofanellinae and Usedomellinae, but the genera held herein contain species which are sometimes very difficult to place in one genus or the other or to a representative of one subfamily or the other. These subfamilies may, therefore, not be very useful.” Despite this statement, Bandel (2005) continued to use both taxa in his paper. However, it is indeed difficult to apply Gründel's (1998) concept in some cases (e.g., Camponaxis). Therefore we are reluctant to propose a subdivision of Tofanellidae into subfamilies and further studies of more fossil representatives are needed.
Fig. 8.
Coaxial heterostrophic protoconchs of Mathilda and Tofanella sensu Bandel (1995) do not show principal differences. A. Mathilda bolina (von Münster, 1841) sensu Bandel (1995), Alpe di Specie, N Italy, Late Triassic; from Bandel (1995: pl. 2: 2). B. Tofanella cancellata Bandel, 1995, Cassian Formation, Campo, Dolomites, N Italy, Late Triassic; from Bandel (1995: pl. 11: 8).
Genus Tofanella Bandel, 1995 Figs. 8B, 9A, B.
Type species: Turritella decussata von Münster, 1841, original designation; Late Triassic, North Italy.
Included species: Turritella decussata Münster, 1841, Late Triassic; Tofanella cancellata Bandel, 1995, Late Triassic; ?Tricarilda octoangulata Gründel, 2006, Bathonian; several undescribed species from the Pliensbachian of England (JG, own observation). Diagnosis.—“The turriculate shell has a major keel on the first whorls of the teleoconch, which disappears on later whorls as they become almost flat. The spiral sculpture is crossed by few collabral elements. The protoconch has a smooth surface, and the embryonic shell is immersed in its apex. In the larval whorls the sinistral coiling changes into dextral coiling before onset of the teleoconch. With transition from larval to adult shell sculpture and whorl shape change drastically” (Bandel 1995: 21).
Stratigraphic and geographic range.—Late Triassic to Pliensbachian; England, ?France, North Italy.
Genus Cristalloella Bandel, 1995
Remarks.—Kaim (2004) and Bandel (2005) considered Wonwalica Schröder, 1995 (December) to represent a junior synonym of Cristalloella Bandel, 1995 (November). The species known to date form two morpho-groups which have been used as subgenera by Gründel (2006): Cristalloella (Cristalloella) and Cristalloella (Wonwalica).
Subgenus Cristalloella (Cristalloella) Bandel, 1995 Fig. 9C. Type species: Cristalloella cassiana Bandel, 1995, original designation; Late Triassic; North Italy.
Included species: Cristalloella cassiana Bandel, 1995, Late Triassic; Wonwalica spiralocostata Gründel, 1998, Callovian; Cristalloella parva Bandel, Gründel, and Maxwell, 2000, late Early Jurassic—early Middle Jurassic; Cristalloella (Cristalloella) carinata Gründel, 2006, Bathonian.
Emended diagnosis.—Shell often very slender and with numerous whorls. Axial and spiral ribs cover the whorls. The keel is strong. Shell with flat and angular base. A strong border rib is developed.
Stratigraphic and geographic range.—Late Triassic to Callovian; Germany, France, New Zealand, North Italy.
Subgenus Cristalloella (Wonwalica) Schröder, 1995 Fig. 9D.
Type species: Wonwalica minuta Schröder, 1995, original designation; Valanginian, Poland.
Included species: Cristalloella sinuata Bandel, 1995, Late Triassic; Cristalloella delicata Bandel, 1995, Late Triassic; Wonwalica minuta Schröder, 1995, Valanginian; Wonwalica n. sp. sensu Gründel 1999b, early Bathonian; Cristalloella boczarowskii Kaim, 2004, Valanginian; Cristalloella (Wonwalica) pusilla Gründel, 2006, late Bathonian; Cristalloella (Wonwalica) sp. nov. sensu Gründel 2007b, Pliensbachian; Cristalloella (Wonwalica) bandeli Gründel, 2007a, late Toarcian—early Aalenian.
Diagnosis.—Shell mostly relatively broad and with only few whorls (in relation to the typical subgenus). The keel is as strong as in C. (Cristalloella). The base is always convex and lacks a bordering rib against the whorl face.
Stratigraphic and geographic range.—Late Triassic to Early Cretaceous; Germany, France, North Italy.
Genus Neodonaldina Bandel, 1996 Fig. 9E.
Type species: Spirocyclina elongata Zardini, 1978, original designation; Late Triassic, North Italy.
Included species: Spirocyclina elongata Zardini, 1978, Late Triassic; ?Neodonaldina ampezzana Bandel, 1996, Late Triassic; Neodonaldina sinuata Gründel and Nützel, 1998, Pliensbachian; Neodonaldina sterpa Gründel, 2006, late Bathonian; Neodonaldina carixiana Gründel, 2007b, Pliensbachian.
Diagnosis.—Shell slender with convex whorls; whorls not shouldered; suture deep; protoconch tofanellid, consisting of about two whorls; teleoconch whorls ornamented with spiral ribs which can become weaker during ontogeny; growth lines opisthocyrt to parasigmoidal; base convex, not demarcated from whorl face.
Remarks.—Neodonaldina has been assigned to the family Donaldinidae. However, the type species (Bandel 1996: fig. 5d; see also Fig. 9E1 herein) as well as other species (e.g., N. carixiana; Gründel 2007b: pl. 6: 23) do not have a donaldinid protoconch but a tofanellid one sensu Bandel (2005: 8, 19).
Stratigraphic and geographic range.—Late Triassic to Bathonian; Germany, France, North Italy.
Genus Graphis Jeffreys, 1867
(= Rotfanella Gründel, 1998)
Fig. 9F, G.
Type species: Turbo unicus Montagu, 1803 (= junior subjective synonym of Turbo albidus Kanmacher, 1798), original designation; Recent; North Atlantic and Mediterranean.
Included Jurassic species: Rotfanella rotundata Gründel, 1998, Callovian; Rotfanella sp. nov. sensu Gründel 1998, Bathonian; Rotfanella herrigi Gründel, 1999b, Bathonian; Rotfanella weissi Gründel, 1999b, late Toarcian—early Aalenian; Graphis sinecostata Gründel, 2007a, late Toarcian—early Aalenian; Graphis sp. sensu Gründel 2007b, Pliensbachian.
Diagnosis.—Shell small with a blunt apex; protoconch with two whorls, broader than the first teleoconch whorl, with or without radial ribs; teleoconch whorls convex with distinct suture; ornament consists of numerous parasigmoidal axial ribs, crossed by numerous weak spiral striae; base convex and without any border rib to the flank; aperture rounded, small.
Remarks.—Bandel (2005: 21, figs. 64–67) re-described and illustrated the type species of Graphis. This species has the same characters as Jurassic species of Rotfanella (see Fig. 9G). Therefore Rotfanella Gründel, 1998 represents a synonym of Graphis. However, Bandel's (2005) synonymization of Urlocella Gründel, 1998 with Graphis is unjustified. Urlocella differs from Graphis in having a narrower protoconch (smaller diameter than first teleoconch whorl) and in showing a conspicuous reduction of the ornament during ontogeny.
Stratigraphic and geographic range.—Early Jurassic (Pliensbachian) to Recent; Germany, Poland.
Genus Camponaxis Bandel, 1994
Fig. 9H.
Type species: Cerithium (?) lateplicatum Klipstein, 1843, original designation; Late Triassic, North Italy.
Included species: Cerithium (?) lateplicatum Klipstein, 1843, Late Triassic; Coronaria subcompressa Kittl, 1894, Late Triassic; Katosira beneckei Kittl, 1894, Late Triassic; Camponaxis zardiniensis Bandel, Gründel and Maxwell, 2000, late Early Jurassic—early Middle Jurassic; ?Rotfanella costigera Gründel, 2003c, Callovian (?); ?Graphis sp., cf. costigera Gründel, 2003 sensu Gründel 2007b, Pliensbachian; ?Iravadia (Pseudonoba) ponderi Kiel and Bandel, 2003, Late Cretaceous.
Emended diagnosis.—Shell slender; whorls convex; suture deep; protoconch tofanellid; teleoconch ornamented with strong, straight axial and weak to absent spiral ribs; base convex, not demarcated from whorl face.
Remarks.—Rotfanella costigera and Graphis sp., cf. costigera differ from typical Graphis-species in size, in having fewer but stronger axial ribs which are not or only weakly parasigmoidal, and in lacking a spiral ornament. According to these characters, they are closer to the type species of Camponaxis and they can be considered to represent descendants of this genus. Iravadia (Pseudonoba) ponderi has also a tofanellid protoconch and the ornament of the first teleoconch whorl (the only preserved one) consists exclusively of relatively few, strong, straight axial ribs. According to its shell shape, protoconchmorphology, and teleoconch ornament, this species could also represent a species of Camponaxis. Kiel and Bandel (2003) suggested that Iravadia (Pseudonoba) ponderi resembles ?Chevallieria sp. sensu Schröder (1995) (= Usedomella schroederi Gründel, 1998) and placed this species in the family Iravadiidae (Rissoidea, Caenogastropoda).
Stratigraphic and geographic range.—Late Triassic to Early— Middle Jurassic boundary; Callovian to Late Cretaceous questionable; North Italy, Poland, ?Germany.
Fig. 9.
Type species and examples for Triassic and Jurassic genera of the family Tofanellidae. A, B. Tofanella laevigata (von Münster, 1841), Cassian Formation, Alpe di Specie, Dolomites, N Italy, Late Triassic A. From Bandel (1995: pl. 10: 1). B. From Bandel (1995: pl. 10: 2). C. Cristalloella (Cristalloella) cassiana Bandel, 1995, Cassian Formation, Campo, Dolomites, N Italy, Late Triassic; from Bandel (1995: pl. 10: 9). D. Cristalloella (Wonwalica) minuta Schröder, 1995, Wąwał, Poland, Valanginian; from Schröder (1995: pl. 10: 1). E. Neodonaldina elongata (Zardini, 1978), Cassian Formation, Alpe di Specie, Dolomites, N Italy, Late Triassic. Protoconch (E1) from Bandel (1996: fig. 5d), whole specimen (E2) from Bandel (1996: fig. 6a). F. Graphis rotundata (Gründel, 1998), borehole Heringsdorf 4/63, Germany, middle Callovian; from Gründel (1998: pl. 1: 5). G. Graphis albida (Kanmacher, 1798), Pliocene, Nice/France; from Bandel (2005: fig. 64). H. Camponaxis lateplicata (Klipstein, 1843), Cassian Formation, Misurina, Dolomites, N Italy, Late Triassic; from Bandel (1995: pl. 14: 3). I. Usedomella laevigatoidea (Gründel, 1993), borehole Kłęby 1/37 (formerly Klemmen), Poland, Callovian; from Gründel (1998: pl. 2: 19). J. Urlocella minuera Gründel, 1998, bore Kłęby 1/37, late Bathonian; from Gründel (1998: pl. 1: 11).
Genus Usedomella Gründel, 1998 Fig. 9I.
Type species: Hyala? laevigatoidea Gründel, 1993, original designation; Callovian, erratic boulder from North Germany.
Included species: Hyala? laevigatoidea Gründel, 1993, late Bathonian—Callovian; Usedomella schroederi Gründel, 1998, Pliensbachian; Usedomella lata Gründel, 1998, late Bathonian—Callovian; Usedomella magnoconcha Gründel, 1998, late Bathonian; Usedomella winkleri Gründel, 1999b, late Toarcian; Usedomella cf. laevigatoidea (Gründel, 1993) sensu Gründel 1999b, Middle Callovian; Usedomella sp. sensu Gründel 2007a, late Toarcian—early Aalenian.
Emended diagnosis.—Shell small, slender; whorls convex; suture deep; protoconch tofanellid, broader than the first teleoconch whorl, consisting of about two whorls; teleoconch whorls including base smooth; growth lines weakly parasigmoidal; aperture round to oval.
Stratigraphic and geographic range.—Pliensbachian to Callovian; Germany, Poland.
Genus Urlocella Gründel, 1998
Fig. 9J.
Type species: Urlocella minuera Gründel, 1998, original designation; Bathonian to Callovian, Poland and NE Germany.
Included species: Urlocella minuera Gründel, 1998, Bathonian—Callovian; Urlocella sp. nov. sensu Gründel 1998, Pliensbachian; Urlocella cf. minuera Gründel, 1998 sensu Bandel 2005, Pliensbachian.
Emended diagnosis.—Shell slender; whorls convex; suture deep; protoconch tofanellid, consisting of about two whorls; first teleoconch whorl wider than protoconch; teleoconch ornament consists of parasigmoidal axial ribs and spiral ribs; teleoconch ornament reduced during ontogeny; base convex, not demarcated from whorl face; aperture broadly oval.
Remarks.—Kaim (2004) considered Urlocella to represent a synonym of Chrysallida Carpenter, 1856. However, Bandel (2005) did not accept this because Chrysallida has no tofanellid protoconch and therefore represent a genus of the Pyramidellidae. Instead Bandel (2005) considered Urlocella to represent a synonym of Graphis. We consider this synonymy to be unlikely as was outlined above (see Remarks under Graphis).
Stratigraphic and geographic range.—Pliensbachian to Callovian; Germany, Poland.
Genus Conusella Gründel, 1999b
Fig. 10A.
Type species: Conusella conica Gründel, 1999, original designation; late Pliensbachian; Northeast Germany.
Included species: Conusella conica Gründel, 1999a, Pliensbachian; Conusella? pacifica Bandel, Gründel, and Maxwell, 2000, late Early— early Middle Jurassic; ?Conusella? sp. sensu Gründel 2003c, Callovian; Conusella torusa Gründel, 2006, late Bathonian; ?Conusella sp. sensu Gründel 2006, late Bathonian; Conusella sp. sensu Gründel and Kaim 2006, Oxfordian.
Emended diagnosis.—Shell conical; protoconch tofanellid, comprising about two whorls; first teleoconch whorl broader than protoconch; whorls broad in relation to height; suture shallow; whorls smooth except straight growth lines; base convex, not demarcated from whorl face; base indistinctly umbilicated; aperture broadly oval.
Stratigraphic and geographic range.—Pliensbachian to Oxfordian; Germany, Poland, France, New Zealand.
Genus Reinbergia Gründel, 2007b Fig. 10B, C.
Type species: Reinbergia inflata Gründel, 2007c, original designation; late Pliensbachian; NE Germany.
Included species: Only the type species.
Diagnosis.—Shell broadly conical with distinct suture and a tofanellid protoconch. The last whorl is higher than the spire; whorls smooth; growth lines strongly parasigmoidal; base with a distinct umbilicus; umbilicus surmounted by edge; aperture broadly oval (after Gründel 2007: 90).
Stratigraphic and geographic range.—Late Pliensbachian; Germany.
Discussion
The evolution of the Mathildidae in the Jurassic.—Numerous species of the Jurassic Mathildidae are insufficiently known and commonly protoconch and early teleoconch are unknown. Micro-ornaments can only be studied with a SEM and therefore, they have only been depicted in some recent studies. Modern studies were almost exclusively conducted on Early and Middle Jurassic faunas from clay and sandstone rocks of central and western Europe deposited in moderately deep water. There are, however, almost no recent studies on mathildoids from calcareous shallow water deposits which were dominant during the Late Jurassic. Even studies about Mesozoic mathildoids from other regions of the world are rare. As outlined above, the status of taxonomically relevant characters is insufficiently known. For these reasons, the stratigraphic ranges (originations and extinctions) of the genera discussed here, must be treated with caution and certainly must be continuously updated.
Fig. 10.
Type species and examples for Jurassic genera of the family Tofanellidae. A. Conusella conica Gründel, 1999, Grimmen, Germany, late Pliensbachian. Whole specimen (A1) from Gründel (1999: pl. 8: 8); protoconch in apical view (A2) from Gründel (1999: pl. 9: 2). B, C. Reinbergia inflata Gründel, 2007, borehole Kb Rnb Gm 4/66 Reinberg, Germany, late Pliensbachian.B. FromGründel (2007: pl. 7: 6, 7).C. FromGründel (2007: pl. 7: 8).
Bandel (1995) showed that Mathildoidea were richly diversified in the Late Triassic. There was a considerable diversity decline at the Triassic—Jurassic boundary but the Jurilda-group survived. However, it should be kept in mind that most of the Triassic diversity has been reported from tropical intra-platform basins partly with transported shallow water material (Cassian Formation). In contrast most of the Jurassic data come from offshore soft bottoms of Central Europe with amore temperate climate. Both occurrences differ considerably in facies and depositional environment. Therefore, evolutionary considerations based on the composition of these Mesozoic mathildoid faunas (including Gordenellidae and Tofanellidae) must take into account facies differences as well as their different age. Mathildoid faunas from other parts of the world are poorly known or completely unknown. Therefore, the impact of the end-Triassic extinction is certainly biased.Gründel (1997: 153, table 2) gave an overviewover the evolution of the Mathildidae from the Triassic to the Recent. The present study on Jurassic Mathildidae corroborates and improves these results.
Kaim (2004: 168, fig. 138) constructed a stratophenetic phylogenetic tree of Mathildoidea, which is on the specieslevel at least for Jurassic representatives. In this tree, Mathildidae are descendants of the Late Paleozoic Donaldinidae. Tricarilda is considered to represent a synonym of Mathilda. This tree also shows Promathildia (= Jurilda herein) and Mathilda as being present as early as Triassic. Carinathilda and Gymnothilda are descendants of Promathildia. Erratothilda (adelphotaxon of Carinathilda) togetherwith Tuba Lea, 1833 (not yet found in the Jurassic) represents a lineage of equal rank to the group previously outlined. However, according to Kaim (2004) it is also possible that Carinathilda and Erratothilda are congeneric.
After an apparent considerable decline of Mathildoidea at the Triassic/Jurassic-transition, the Jurilda-group radiated in the Early and early Middle Jurassic. Numerous species with generally rather conservative morphology evolved. Since the Bathonian new genera occur indicating an increasing morphological disparity. Gründel (1997) also discussed the possible relationships of genera within the group.
Tangarilda differs from other JurassicMathildidae in having opisthocyrt growth lines with the backmost point between adapical and middle spiral rib. The genus seems to stand somewhat isolated in the family in this respect. The phylogenetic meaning of this character is not yet clear. In fact, such growth lines are not present in Mathildidae after the Hettangian (Sinemurian?) although numerous well-preserved mathildids are known from the post-Hettangian Jurassic.
It seems possible that there are closely related Late Triassic taxa with similar growth lines (AN personal observation) and that these taxa represent an old evolutionary line which became extinct in the late Early Jurassic.
According to the current state of knowledge, the first certain occurrence of Jurilda is of Hettangian age. Bandel (1995) reported very similar “Promathildia”-species from the Late Triassic Cassian Formation e.g., Promathildia decorata (Klipstein, 1843). However, the phylogenetic relationships of the diverse Mathildoidea from the Cassian Formation to Jurassic and younger forms are far from being clear (AN and JG unpublished data). It is for instance unclear, whether Triassic species with two primary spiral ribs can be assigned to the genus Jurilda. At least in some of these Triassic species, the growth line pattern differs from that of typical Jurilda species and resembles that of the genus Tangarilda. Other late Triassic species, e. g., Promathildia sculpta (Kittl, 1894) sensu Bandel (1995), have numerous weak spiral ribs and this pattern resembles the micro-ornament of some Jurassic species but is distinctly coarser.
At present, it can be stated that either Jurilda itself or closely related forms were present as early as Late Triassic. This represents a continuous evolutionary lineage which crosses the critical Triassic—Jurassic boundary. This Jurilda lineage continues at until the Early Cretaceous and comprises species with a rather conservative morphology. The younger history of this group is unknown. None of the Recent species described by Bieler (1995) belongs to the Jurilda-group.
Gymnothilda can be derived from Jurilda by a reduction of the ornament. The oldest known species is Gymnothilda dispiralis from the Bathonian. This species has two primary spiral ribs. Forms with a single primary spiral rib are known from the Early Cretaceous. There are also Cretaceous species with two primary spiral ribs. Possibly a reduction of primary spiral ribs occurred within this genus. Gymnothilda tomaszina from the Valanginian has a micro-ornament which resembles that of Carinathilda. Gymnothilda-species have been reported only from a few stages (Bathonian, Valanginian, Campanian) and some are only known from juvenile specimens. Therefore, the evolution of this genus is still largely unknown.
The genus Bathraspira is only known from the Cretaceous. Protoconch and early ontogeny have been unknown until recently and the genus was assigned to the Procerithiidae or Cerithiidae. Kiel (2006) described a species with protoconch and early teleoconch whorls (Gymnothilda pagodoidea); this species combines a mature teleoconch typical for Bathraspira and an early stage typical for Gymnothilda with a single primary spiral rib. At least this species can be interpreted as a descendant of Gymnothilda. However, it is unclear whether this is true for other or all species of Bathraspira.
The evolution of the Jurilda—Gymnothilda—Bathraspira lineage encompasses a reduction of the sculpture. However, another lineage related to Jurilda is characterized by a strengthening and complication of the ornament. Carinathilda has two primary spiral ribs and a conspicuous ornament of fine spiral ribs. It is very likely that Carinathilda originated from a Jurilda-like ancestor. Jurilda naricata naricata (Gründel, 1973) represents a transitional stage. It resembles Carinathilda in having a strongly convex base, in the ornament of spiral ribs on the base, and in having keeled whorls. A micro-ornament may be present or lacking. In any case it is weaker than in Carinathilda (Gründel 1997: 137). If the micro-ornament was stronger and would form a constant character of this subspecies, then it could be placed in Carinathilda.
Angulathilda closely resembles Carinathilda. However, the base of Angulathilda is less convex and the base is demarcated from the whorl face by a strong spiral or a pronounced edge. The keel is more pronounced in Angulathilda and the whorls are concave above and below it. These differences may be easily derived from the bauplan of Carinathilda. Both genera seem to appear in about the same time interval, during the Bathonian.
The oldest mathildoid with three primary spiral ribs is Tricarilda. This genus is probably as old as Hettangian and certainly as old as Sinemurian. Bandel (1995) reported Late Triassic mathildoids with three primary spiral ribs but those taxa differ in several other characters and are probably not members of the family Mathildidae. Tricarilda ranges into the late Early Cretaceous and its younger fate is unknown. The genus is not present among the modern forms reported by Bieler (1995).
Mathildoids with more than three primary spiral ribs are assigned to the genus Mathilda. Such species are known from the Toarcian onward and range into the Late Cretaceous (Dockery 1993). Whether these Mesozoic forms are congeneric with the Pliocene type species of Mathilda (see Gründel 1976 for a re-description) and with the modern species described by Bieler (1995) remains unclear.
Turrithilda cassiana Bandel, 1995 and T. dockeryi Bandel, 1995 from the Late Triassic Cassian Formation represent mathildid species with four primary spiral ribs. These species have been assigned to Bandelthilda Gründel, 1997 by Gründel (1997). They differ from Jurassic Mathilda-species in having smaller, coaxial protoconchs, two primary spiral ribs being strengthened, and angulate the whorl face; the whorls are parallel to the shell axis between these angulations. It needs to be tested whether these species belong to the stem group of Mathilda (Nützel and Gründel in preparation).
Erratothilda resembles the Jurilda-group in having a conspicuous micro-ornament. However, Erratothilda has three or more primary spiral ribs. Weak spiral striae are also present in some Tricarilda species (e.g., T. plana [Gründel, 1973] and T. waltheri Gründel, 1997). We therefore assume that Erratothilda is derived from Tricarilda. Erratothilda resembles Angulathilda in shell shape (keeled whorls, concavity above and below keel, strong spiral rib at edge to base). Erratothilda has been reported from the Callovian to the Early Cretaceous. Mathildoids with a distinct micro-ornament have also been reported from the Late Cretaceous e.g., Echinimathilda microstriata Dockery, 1993.
In conclusion, Mathildidae are as old as Late Triassic and had a first radiation during the Late Triassic including various species and several genera. Most of these taxa became extinct at the end-Triassic mass extinction event. According to the current state of knowledge, at least one evolutionary line survived the end-Triassic extinction: the Jurilda-group. It is still unknown whether the genus Jurilda itself was present in the Late Triassic or whether closely related forms were present. Tangarilda represents an additional evolutionary lineage which probably originates as early as Late Triassic. Tricarilda is probably a descendant of the Jurilda-group. In the Early Jurassic, only a radiation on the species level can be recognized. The Pliensbachian—Toarcian crisis had no impact on the genus level in mathildids. Mathilda originates in the Toarcian. A distinct radiation can be recognized in the Bathonian; Gymnothilda, Carinathilda, Angulathilda, and Erratothilda appeared at about the same time. With the exception of Carinathilda, these genera as well as Jurilda, Tricarilda, and Mathilda were still present in the Early Cretaceous. Together with the Early Cretaceous Bathraspira, these genera show that Mathildidae were diverse during the period from the Middle Jurassic to the Early Cretaceous.
The evolution of the Gordenellidae in the Jurassic.— Gründel (2000) and Guzhov (2007) suggested that Promathildia (= formerly Clathrobaculus) and Gordenella are closely related to each other. Promathildia has all diagnostic characters of Gordenellidae except of the concave whorl face and the ontogenetic reduction of the teleoconch ornament.
Promathildia and Gordenella share a transaxial widely exposed protoconch. In the Jurassic such protoconchs are only known from Ebalidae (see Fig. 5C, D; Schröder 1995; Gründel 1998; Kaim 2004). Even Guzhov (2007: 386) emphasized the characteristic protoconch morphology in Gordenella and Promathildia. This suggests that they are closely related and separates them from the Mathildidae. In summary, Promathildia is here considered to represent a member of the Gordenellidae (in contrast to Gründel 2000). According to our interpretation, this genus shows the most basal morphology of this family and represents a phylogenetic link to the Mathildidae. Guzhov's (2007) though we are aware that this phylogenetic scenario is rather hypothetical due to the insufficient knowledge of majority of involved species.
The family Gordenellidae contain only a few genera. Apparently, there are two evolutionary lineages. Promathildia is known since the earliest Jurassic. Very similar species which belong to Promathildia or a closely related genus haven been reported from the Late Triassic (Haas 1953). However, these species are insufficiently documented. Promathildia share some characters with the mathildid Tricarilda: three primary spiral ribs and a basically mathildoid ornament throughout its teleoconch ontogeny. Tricarilda is known since the earliest Jurassic. Promathildia is more slender and has more whorls than Tricarilda and the protoconch morphology of both genera differs from each other. The relationships of both genera are not yet clear. It seems possible that both genera share a last common ancestor in the Triassic. Promathildia ranges into the Early Cretaceous; its younger evolution is unknown. Several Cretaceous mathildoid gastropods were described which could belong to Gordenellidae orMathildidae (e. g., Mathilda coxi Abbass, 1962 and M. ahmadi Abbass, 1962). However, these taxa are insufficiently known so that a safe taxonomic assignment is unwarranted.
Gordenella closely resembles Promathildia in shape, ornament of the early teleoconch and the protoconch morphology. This suggests that Gordenella probably evolved from a Promathildia-like ancestor (Gründel 2000; Guzhov 2007). Gordenella differs from Promathildia by its pronounced ontogenetic change of the teleoconch ornament. Gordenella ranges from the Bajocian to the Oxfordian.
The yet unnamed genus and species (to be named elsewhere) illustrated herein (Fig. 6C) is known from the Pliens bachian of Germany. Its early teleoconch has a “Promathildia-like” ornament as is typical for Gordenellidae. As in Promathildia the position of the spiral ribs remains fairly stable throughout ontogeny; however, they become weaker. In contrast to Promathildia, the new genus adds numerous spiral ribs and striae during ontogeny. At the same time the axial ribs are replaced by very numerous strengthened growth lines. The ontogenetic change of the teleoconch ornament differs from that in Gordenella. The new genus and Gordenella are probably not very closely related to each other. Moreover, the relationship of the new genus to Promathildia is not yet clear because the protoconch of the new Plienbachian genus is unknown.
Fig. 11.
Stratigraphic ranges of mathildoid genera with indications of some possible phylogenetic relationships.
The second gordenellid lineage initiates with the Late Triassic Camponella. Camponella closely resembles Proacirsa (Pliensbachian—Early Cretaceous) but differs in being smaller, in having fewer whorls, and in having an umbilicus. It is very likely that Proacirsa evolved from a Camponella-like ancestor. The stratigraphic gap between the occurrences of both genera spanning the Carnian to Pliensbachian is probably a result of preservation. Camponella and Proacirsa closely resemble the genus Schafbergia Gatto and Monari, 2010 (Liassic, Alps). Schafbergia differs from these genera in having weaker spiral ribs which are confined to the abapical portion of the whorls. Moreover, in Schafbergia, the spiral ornament on the whorl flanks persists throughout the entire ontogeny and it lacks the broadening of the spiral ribs on the base. All three genera are probably closely related to each other although their exact phylogenetic relationships are unknown. Turritelloidea differs from Proacirsa by its teleoconch ornament of broad spiral ribs and narrow furrows throughout its ontogeny (a similar ornament is present on the base of Proacirsa). It differs from Schafbergia in having broadened spiral ribs on mature teleoconch whorls and in details of the early whorls. The genera Camponella, Proacirsa, and Turritelloidea share an almost coaxial protoconch (the protoconch of Schafbergia is unknown) which differentiates them from the Promathildia-branch. Turritelloidea seems to have the longest range and originates as early as Hettangian and probably ranges into the Late Cretaceous.
Seemingly, the end-Triassic crisis had no serious effect on the Gordenellidae. The Proacirsa-branch is certainly and the Promathildia-branch is probably as old as Triassic. Few new genera occur in the Jurassic and there seems to be no strong radiation of this group. Promathildia and Proacirsa are the most diverse and longest ranging genera.
Remarks on the family Anoptychiidae Bandel, 1994.— Anoptychia encompasses high-spired shells with axial ribs on the early teleoconch, which are reduced subsequently so that the shell is smooth. Bandel (1995: 16) based the new family Anoptychiidae on a heterostrophic species from the Cassian Formation, which he identified as Melania supraplecta Münster, 1841 (type species of the genus Anoptychia Koken, 1892). However, according to Nützel (1998) and Nützel et al. (2003), Bandel (1994, 1995) misidentified his material. The protoconch of the type species of Anoptychia is still unknown and therefore, its higher systematic placement is doubtful. High-spired species in which teleoconch ribs are reduced during ontogeny are also present in other gastropod groups, e.g., in the family Zygopleuridae (Caenogastropoda). Presently, it is unclear whether Anoptychia belongs to the Heterobranchia or Caenogastropoda and therefore Anoptychia is not considered here. The material presented by Bandel (1995) from the Late Triassic seems to represent a genus which has not been reported from the Jurassic.
The Jurassic evolution of the Tofanellidae.—The knowledge about the Tofanellidae is rather new. Nearly all Jurassic representatives have been described since 1995. Most of them are from Germany and Poland. The Late Triassic tofanellids were studied by Bandel (1995). All of these species are from the Carnian Cassian Formation (N Italy). Morphological details including the protoconch morphology of the minute species could only be studied after scanning electron microscopes were available. It is clear that only a small portion of the gone diversity of this group has been documented so far. Bandel (1995) and Gründel (1998) made first assumptions about the relationships of fossil tofanellids to modern descendants. Kaim (2004) suggested a close phylogenetic relationship of tofanellids and Graphis. Bandel (2005) showed that the Recent genus Graphis belongs to the Tofanellidae and that there are closely related Jurassic forms which do not differ from their modern counterparts. Gründel (2007a, b) synonymized the Jurassic genus Rotfanella with the modern genus Graphis and thus Graphis represents an extremely long-lasting genus. There is almost no information about tofanellids from the Late Cretaceous to the Cenozoic.
Within the Tofanellidae, two groups with distinct shell morphology can be recognized. These groups may represent real phylogenetic lineages:
(i) The first tofanellid group is characterized by an inflated last protoconch whorl which is broader than the first teleoconch whorl and by a very slender, almost cylindrical teleoconch (slow increase of whorl width during ontogeny). The following genera belong to this group: Tofanella, Cristalloella, Graphis, Neodonaldina, and Usedomella. Tofanella, Cristalloella (including both subgenera), and Neodonaldina are as old as Late Triassic. The earliest reports of Graphis and Usedomella are from the Pliensbachian. Within this group, there is a tendency to reduce the ornament. C. (Cristalloella) and some representatives of Tofanella have keeled whorls and a strong ornament of axial ribs and weaker spiral ribs. The transition from the whorl face to the base is formed by an edge with a spiral rib. Cristalloella (Wonwalica) has a weaker keel and the transition from the whorl face to the base is rounded. Graphis, Neodonaldina, and Usedomella have convex, rounded whorls without keel. Graphis has a complex ornament consisting of axial and spiral ribs. Neodonaldina has only spiral ribs which becomes rather weak in some species. Usedomella is smooth and only some species show remains of axial ribs in the subsutural portion of the first teleoconch whorl.
(ii) The second tofanellid group encompasses the genera Camponaxis, Urlocella, Conusella, and Reinbergia. Their protoconch is not inflated and the first teleoconch whorl is broader than the teleoconch. The teleoconch is not as slender as in the first group and the whorls increase more rapidly in width so that the habitus is broader conical. The oldest known genus of this group is Camponaxis from the Late Triassic. The oldest known representatives of the other genera have been reported from the Pliensbachian. Camponaxis has axial and weaker spiral ribs on all teleoconch whorls. In Urlocella, the ornament is restricted to the early teleoconch whorls. Conusella and Reinbergia are smooth.
To date, five genera (subgenera) of the Tofanellidae are known from the Late Triassic. All of them survived into the Jurassic. Therefore, the end-Triassic mass extinction obviously did not affect this family on the generic level. However, there is no tofanellid species which is known from the Triassic as well as from the Jurassic. On the one hand, this is preservation driven because no tofanellid occurrences are known between the Carnian and the Pliensbachian. On the other hand, the facies and geographic differences between the Late Triassic occurrences (all from the Cassian Formation) and the Jurassic occurrences (German-Polish Basin) make it unlikely that identical species are found before and after the Jurassic—Triassic boundary. Seemingly, a tofanellid radiation occurred in the Early Jurassic. Graphis, Usedomella, Urlocella, Conusella, and Reinbergia seem to occur at about the same time in the Pliensbachian. However, it is possible or even likely that this contemporaneous appearance is result of preservation and/or sampling biases. Tofanella and Reinbergia have not been reported from the post-Pliensbachian. Cristalloella (Cristalloella), Neodonaldina, Usedomella, and Urlocella seem not to survive the Middle to Late Jurassic boundary according to the current state of knowledge. The younger evolutionary history of the Tofanellidae is largely unclear. Only Graphis is also known from the Recent.
In conclusion, the family Tofanellidae had a first radiation in the Late Triassic. The radiation could be somewhat older because only the Cassian Formation produces specimens which are so well-preserved that tofanellids can be recognized whereas older Triassic formations generally lack this excellent preservation. Seemingly it was not affected by the end-Triassic crisis. A second radiation occurs in the Pliensbachian and the family reaches its highest diversity between the Pliensbachian and the Callovian. Few taxa have been reported after this period. However, it must be kept in mind that tofanellids are known from very few occurrences. Graphis is a tofanellid genus which ranges from the Pliensbachian to the Recent. This is one of the longest generic ranges known from gastropods.
Conclusions
We have presented a synoptic classification of Mesozoic (and some modern) mathildoid taxa treated herein (for a key see Appendix 1). As stated above, it is based on shell characters of which the biological meaning is poorly known or unknown. In the absence of a phylogenetic framework based on anatomical and molecular studies, the present arrangement is justified especially that it largely concerns fossil taxa, which status would hardly be clarified by molecular studies. Nevertheless, such studies on living mathildoids certainly would help to better understand the phylogenetic meaning and significance of shell characters in Mathildoidea. We would like to emphasize that not all Mesozoic mathildoid species are included in this classification. We omitted especially those taxa which are so poorly known that any generic and family assignment is highly speculative.
About 150 early Mesozoic (mostly Early and Middle Jurassic) species of the heterobranch superfamily Mathildoidea are classified into four families and 27 genera. Most taxa are assigned to the families Mathildidae, Gordenellidae, and Tofanellidae while the Triassic family Anoptychiidae holds only a single genus and is restricted to the Late Triassic. A high mathildoid diversity has been recognized from the Late Triassic Cassian Formation (Kittl 1894; Bandel 1995, 1996). Many of these taxa are unknown form the Jurassic and probably became extinct during the end-Triassic mass extinction event. However, at least five genera (probably eight) survived the end-Triassic mass extinction event. Tricarilda, Jurilda, and Promathildia are rather conservative, long ranging groups of high Jurassic species diversity. They probably gave rise to the modern Mathildidae.
Acknowledgements
We thank Rüdiger Bieler (Field Museum, Chicago, USA) and Heinz Kollmann (Naturhistorisches Museum, Vienna, Austria) for their reviews. We also thank Andrzej Kaim (Instytut Paleobiologii PAN, Warszawa, Poland) and Philippe Bouchet (Muséum national d'histoire naturelle, Paris, France) for helpful comments on an earlier version of the manuscript. The first author thanks Helmut Keupp for the permit to use the facilities of the Palaeontology Department of the Free University Berlin and Reinhard Schmode (Rheurdt, Germany) for giving material from the Callovium of La Motte Bourbon (France). The Deutsche Forschungsgemeinschaft is acknowledged for financial support (project GR 2707/2-1 and NU 96/11-1).
References
Appendices
Appendix 1
Key to mathildoid genera and subgenera.
Mathildidae
Protoconch of mathildid type, mostly transaxial or medioxial, not completely elevated, rarely coaxial; teleoconch with ornament of spiral ribs and reinforced growth lines or collabral axial threads; ornament normally not reduced during ontogeny (except for Gymnothilda).
1 Backmost point of growth lines between primary spiral ribs 1 and 2 Tangarilda
2 Backmost point of growth lines on primary spiral rib 2
2.1 Microornament lacking or weak
2.1.1 Ornament not reduced during teleoconch ontogeny
2.1.1.1 2 primary spiral ribs Jurilda
2.1.1.2 3 primary spiral ribs Tricarilda
2.1.1.3 4 and more primary spiral ribs Mathilda
Ornament reduced during teleoconch ontogeny; 1 or 2 primary spiral ribs Gymnothilda
2.2 Distinct microornament present; whorls with keel
2.2.1 2 primary spiral ribs
2.2.1.1 Transition from whorl face to base rounded Carinathilda
2.2.1.2 Transition from whorl face to base with keel Angulathilda
3 or more primary spiral ribs; transition from whorl face to base with keel Erratothilda
Gordenellidae
Protoconch and early teleoconch as in Mathildidae; later teleoconch in most cases with considerable ontogenetic change; shell mostly relatively large and slender with numerous whorls
1 Typical mathildid ornament during entire teleoconch ontogeny with no or few changes; protoconch transaxial and widely elevated Promathildia
2 Ornament changes considerably during teleoconch ontogeny
2.1 Whorl face straight to concave; abapical primary spiral ribs shifts towards abapical suture Gordenella
2.2 Whorl face of mature teleoconch whorls convex
2.2.1 Ornament reduced in latest teleoconch whorls; base with broad spiral ribs
2.2.1.1 Shell small with few whorls, umbilicated Camponella
2.2.1.2 Shell tall with many whorls, not umbilicated Proacirsa
2.2.2 All teleoconch whorls ornamented
2.2.2.1 Whorl and base of late teleoconch whorls ornamented with broad ribbon-like spiral ribs Turritelloidea
2.2.2.2 Early teleoconch whorls with few axial ribs which are as strong as spiral ribs; later whorls with numerous reinforced growth lines and spiral threads new unnamed genus
2.2.2.3 Early teleoconch whorls with numerous axial and spiral ribs of about equal strength; later whorls with weak spiral ribs only Schafbergia
Tofanellidae
Shell small; protoconch tofanellid, i.e., coaxial with change from sinistral to dextral within larval shell and sunken initial whorl
1 Teleoconch strongly ornamented, without reduction in late whorls
1.1 Whorls with keel
1.1.1 Only early teleoconch with keel, whorl face more or less straight in later whorls Tofanella
1.1.2 All teleoconch whorls with keel
1.1.2.1 Shell very slender with numerous whorls, with keel or edge at transition to base Cristalloella (Cristalloella)
1.1.2.2 Shell more or less stout, with few whorls, transition to base rounded Cristalloella (Wonwalica)
1.2 Whorls convex, shell with few whorls
1.2.1 Whorls with few, straight axial ribs; spiral ribs weak or lacking Camponaxis
1.2.2 Whorls with numerous parasigmoidal axial ribs and weaker spiral ribs Graphis
1.2.3 Whorls with spiral ribs only Neodonaldina (part)
2 Whorls convex, ornament reduced during ontogeny
2.1 Whorls with spiral ornament becoming weaker during ontogeny Neodonaldina (part)
2.2 Whorls with parasigmoidal axial ribs and weaker spiral ribs; axial ribs weakening during ontogeny Urlocella
3 Whorls convex, smooth
3.1 Shell slender, protoconch wider than first teleoconch whorl Usedomella
3.2 Shell broadly conical; protoconch narrower than first teleoconch whorl
3.2.1 Growth lines straight; indistinct umbilicus Conusella
3.2.2 Growth lines distinctly parasigmoidal, distinct umbilicus Reinbergia
