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Non-marine and marine palynomorphs were collected from a Telychian through Gorstian rock outcrop located near Allenport, Pennsylvania, USA in the east-central part of the Appalachian Foreland Basin. Close sampling of the section revealed six distinct palynological assemblages of spores, cryptospores, acritarchs and prasinophycean algae, likely deposited in nearshore marine settings. The Silurian Period is a critical time in plant evolution as megafossils found elsewhere indicate that vascular plants (tracheophytes) originated during this interval. Palynoflorules generally show a transition from cryptospore-dominated to miospore-dominated assemblages during the latter half of the Silurian. This transition is evident at Allenport, where over 30 species of miospores and cryptospores are recognized, including two new species: Vermiverruspora cottera and Rugosphaera falloambita. The sequential progression of innovations in exine structure and sculpture seen in the nonmarine palynomorphs at Allenport closely matches evolutionary patterns documented previously in the Appalachian Basin, Avalonia, and elsewhere around the world.
The Cambrian inlier at Beaver Harbour, southern New Brunswick, is now confidently referred to the marginal platform of the late Proterozoic–Early Paleozoic Avalon microcontinent. The sub-trilobitic Lower Cambrian Chapel Island and Random Formations are unconformably overlain by the mafic volcanic-dominated Wade's Lane Formation (new). Late Early Cambrian trilobites and small shelly taxa in the lowest Wade's Lane demonstrate a long Random–Wade's Lane hiatus (middle Terreneuvian–early Branchian). Latest Early–middle Middle Cambrian pyroclastic volcanism produced a volcanic edifice at Beaver Harbour that is one of three known volcanic centers that extended 550 km along the northwest margin of Avalon. Middle Middle Cambrian sea-level rise, probably in the Paradoxides eteminicus Chron, mantled the extinct volcanics with gray-green mudstone and limestone of the Fossil Brook Member. Black, dysoxic mudstone of the upper Manuels River Formation (upper Middle Cambrian, P. davidis Zone) is the youngest Cambrian unit in the Beaver Harbour inlier. Lapworthella cornu (Wiman, 1903) emend., a senior synonym of the genotype L. nigra (Cobbold, 1921), Hyolithellus sinuosusCobbold, 1921, and probably Acrothyra seraMatthew, 1902a, range through the ca. 8 m.y. of the trilobite-bearing upper Lower Cambrian, and H. sinuosus and A. sera persist into the middle Middle Cambrian. Lapworthella cornu and H. sinuosus replaced the tropical taxa L. schodackensis (Lochman, 1956) and H. micansBillings, 1872, in cool-water Avalon.
The biostratigraphy of the upper part of the Mississippian Lower Limestone Formation in the Midland Valley, Scotland is revised using foraminiferal assemblages. This formation was previously assigned exclusively to the upper part of the Brigantian Substage (upper Cf6δ, P2 or latest Visean), whereas the succeeding Limestone Coal Formation (barren of foraminifers and conodonts) was assigned to the Pendleian Substage (lower Cf7, E1 or early Serpukhovian). The foraminifers, in particular those recorded from the Second Hosie and Top Hosie limestones and their lateral equivalents (Anvil and MacDonald limestones), are comparable to Serpukhovian assemblages from the Ukraine and Russia. Consequently, the Visean/Serpukhovian stage boundary is repositioned at the base of the Second Hosie Limestone. This assignment of the Second Hosie Limestone to the Pendleian is reinforced by the first occurrence of the ammonoid Emstites (Cravenoceras), although it occurs 1 m below the Top Hosie Limestone. Pendleian foraminiferal assemblages from northern England, its geographically closest equivalent, are similar but not well enough known for a detailed comparison. A few similarities are found between the foraminiferal assemblages from the Midland Valley and those from southwest Spain and North African basins. Faunas from the Second and Top Hosie limestones and their lateral equivalents allow us to propose an assemblage zone, valid for regional correlations within the British Isles, and the faunas can be potentially used as Serpukhovian markers for western Paleotethyan basins. Two new genera and species are described, Praeplectostaffella anvilensis n. gen. n. sp. and Praeostaffellina macdonaldensis n. gen. n. sp., and two new species, Tubispirodiscus hosiensis n. sp. and Euxinita pendleiensis n. sp.
The uppermost 5–15 m of the Douling Formation in the southern Hunan area, South China, yields a diverse fauna comprised of ammonoids, bivalves, and brachiopods. The brachiopods reported in this paper consist of 51 species in 34 genera and are dominated by the Lopingian (Late Permian) species associated with a few species persisting from the underlying Maokouan (Late Guadalupian). This fauna is of earliest Wuchiapingian in age as precisely constrained by the associated conodont Clarkina postbitteri postbitteri and the Guadalupian-type ammonoid fauna of the Roadoceras-Doulingoceras Zone in the brachiopod horizon. The discovery of the Lopingian species-dominated brachiopod fauna in the earliest Wuchiapingian in southern Hunan suggests a much less pronounced effect of the pre-Lopingian crisis (end-Guadalupian mass extinction) than the end-Changhsingian mass extinction in terms of brachiopods, a contemporaneous onset of the Lopingian recovery/radiation during the pre-Lopingian crisis period, and taxonomic selectivity of the pre-Lopingian crisis in terms of different fossil groups. New taxa are Echinauris doulingensis n. sp., Pararigbyella quadrilobata n. gen. and n. sp. and P. doulingensis n. gen. and n. sp.
Twenty-seven graptolite species are reported from the lowermost Silurian (Rhuddanian) ascensus-acuminatus and vesiculosus biozones of Montagne Noire in southwestern France. Four species are left in open nomenclature, four are new: Normalograptus crassus, Neodiplograptus lautus, Dimorphograptus compactus and Huttagraptus solidus. The joint occurrence of Akidograptus ascensus, Parakidograptus acuminatus and Cystograptus ancestralis, recorded in the Gabian-1 section, suggests correlation of the whole succession at this site with the middle part of a combined ascensus-acuminatus Biozone. Revision of museum collections revealed that other elements that are characteristic of the ascensus-acuminatus Biozone assemblage in peri-Gondwanan Europe, such as Normalograptus trifilis, N. longifilis and Neodiplograptus lanceolatus, have been recovered from several other localities in Montagne Noire that are no longer accessible. The graptolite assemblage of the Gabian-2 section, with common Cystograptus vesiculosus, Dimorphograptus extenuatus, D. elongatus and Atavograptus atavus, belongs to the lower part of the vesiculosus Biozone, whilst the appearance of D. swanstoni and D.? physophora in the upper part of the section represents a higher, although not the uppermost, part of the biozone. This is the first record of a diverse dimorphograptid fauna within the vesiculosus Biozone in the Gondwanan part of Europe.
The Middle and Upper Ordovician sequence of the Langkawi Islands, northwestern peninsular Malaysia, contains 20 species of conodonts belonging to 15 genera and four unidentified species, which are described and illustrated. The following four biostratigraphic zones are established for the study area: the Scolopodus striatus assemblage zone, the Periodon sp. A range zone, the Baltoniodus alobatus range zone, and the Hamarodus europaeus range zone, in ascending order. The Middle Ordovician fauna belongs to the low-latitude, warm-water Australian Province. Conodonts of the H. europaeus zone represent the HDS (Hamarodus europaeus-Dapsilodus mutatus-Scabbardella altipes) biofacies, which has been reported from the cool-water North Atlantic Faunal Region. The middle Arenigian limestones in the study area were deposited on a shallow-water shelf, whereas the late Arenigian to middle Darriwilian limestones formed in hemipelagic deeper-water conditions on an outer shelf or slope.
Cymatograptus bidextro sp. nov. from the Floian “Baltograptus deflexus” Biozone of northwest Argentina represents the oldest expansograptid with an artus type proximal development and a prosicular origin of the first theca. The species bears a variably dextral or sinistral proximal development, previously known exclusively from Tremadocian members of the Anisograptidae, but not from the Dichograptidae. The proximal development types of the Dichograptacea are shown to consist of several independently changing characters and cannot be used as phylogenetically useful descriptors. Proximal developments are more variable than expected and several independent origins of an artus type proximal development can be recognized in the Lower to Middle Ordovician.
New material from the Famennian of Morocco in the southern Maider comprises chondrichthyan teeth (Thrinacodus, Cobelodus, Denaea, Stethacanthus), actinopterygian remains (scales, teeth and hemilepidotrichium) and one acanthodian scale. The absence of crushing teeth suggests deeper water environments for the Maider Basin than the Tafilalt Basin. Vertebrate microremains from the Famennian of Sardinia, including Siamodus and Jalodus teeth, are illustrated and described. Ichthyofaunal relationships of the North Gondwanan platform during the Famennian are examined.
Fossil ceratioid anglerfishes are described from the Upper Miocene (upper Mohnian) deposits of the Puente Formation, Los Angeles Basin, California. The specimens were collected from the laminated turbiditic deposits of the Yorba Member in the eastern sector of the Los Angeles Basin during the construction of a new metro rail line. Five taxa (Borophryne cf. apogon; Chaenophryne aff. melanorhabdus; Leptacanthichthys cf. gracilispinis; Linophryne cf. indica; Oneirodes sp.) belonging to two families, Linophrynidae and Oneirodidae, are described based on nine metamorphosed females. A detailed osteological analysis of the fossils has revealed that they can be tentatively assigned to extant species, suggesting that little or no relevant morphological change has characterized these taxa at least since the Late Miocene. Biogeographic considerations suggest that the Late Miocene ceratioid assemblages of the Los Angeles Basin are strikingly similar to those that currently inhabit the tropical and subtropical eastern Pacific region. From a paleoenvironmental point of view, the excellent preservation of the specimens suggests a reduced turbulence and velocity of the turbidity fluxes. Finally, the comparative study of the bathymetric ranges of the ceratioid taxa recognized in the fossil assemblage described in this paper suggests that the minimum depth of the depositional environment might be estimated at approximately 1,000 m.
New finds of teeth and mandibles of Anchitheriomys from the Hambach opencast lignite mine in Northwest Germany and the first detailed descriptions of other mandibles from South Germany and Switzerland allow a review of the Central European specimens of this rare beaver genus. The metric variation of cheek teeth and especially the great differences in dimensions of incisors can be much better assessed. The observed range in size can be attributed to ontogenetic changes, and all material is assigned to Anchitheriomys suevicus. Stratigraphically, this species is restricted to the early middle Miocene, European Mammalian Neogene biozones MN 5–6.
A new decapod crustacean species, Shinkaia katapsyxis, is reported from the Eocene Humptulips Formation of western Washington, USA. The specimens were collected from a hydrocarbon seep deposit that has been well-documented and contains a well-described molluscan fauna. The new occurrence extends the geologic range of the genus ShinkaiaBaba and Williams, 1998, and subfamily Shinkaiinae Baba and Williams, 1998, into the Eocene from its only other known occurrences in hydrothermal vent environments in the Pacific Ocean. The range extension of an extant decapod genus into the Eocene is not uncommon and adds to the evidence that the Decapoda may be unusually resistant to extinctions and are distinctly conservative evolutionarily.
Description of a new species of crab, Ekalakia exophthalmops, brings to two the number of species within this Late Cretaceous genus from the upper mid-west in North America. Discovery of eyes and orbital structures in both species permits placement of the genus within the superfamily Glaessneropsoidea Patrulius, 1959 and family Glaessneropsidae Patrulius, 1959, extending the range of those taxa from the Late Jurassic into the Late Cretaceous. The extraordinarily large eyes relative to body size suggests that the Jurassic reef-dwelling crabs were adapted for a cryptic lifestyle which preadapted them for the deep-water, dysphotic, level-bottom habitat occupied by the Cretaceous descendants.
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