Habitat partitioning and site fidelity of spawning grounds are well-documented phenomena in extant selachians, but little is known about the reproductive strategies of their fossil relatives. Here we describe the selachian fauna of the Middle to Late Triassic Madygen Formation in southwestern Kyrgyzstan, Central Asia, based on several dozen tooth crowns and egg capsules. The material is assigned to three new taxa: Lonchidion ferganensis, sp. nov., and Palaeoxyris alterna, sp. nov., being teeth and egg capsules of hybodontid sharks, and Fayolia sharovi, sp. nov., being egg capsules of probable xenacanthids. Teeth of L. ferganensis, sp. nov., were almost exclusively found in pelecypod-rich shallow lacustrine mudstones and belong to juvenile individuals. Oxygen and strontium isotope data of tooth enameloid indicate freshwater conditions of the ambient water at the time of tooth mineralization. The egg capsules are common findings in near-shore lake deposits as well. Considering the mass co-occurrence of juvenile teeth and egg capsules in the study area, we propose that hybodontid/xenacanthid sharks recurrently occupied littoral zones of the Madygen lake for spawning. The small number of full-grown individuals points to habitat partitioning of juveniles and adults wherefore the study site is interpreted as a shark nursery. The oviposition strategies inferred from this fossil example are remarkably similar to those of modern sharks, suggesting that the reproductive patterns seen in extant sharks originated well before the Cenozoic.

Remains of the chimaeroid fish Ischyodus are described from the early Kimmeridgian (Late Jurassic) of northeastern Spain. This is the first fossil holocephalan record from the Iberian Peninsula. The material comprises a mandibular tooth plate, two incomplete and isolated symphyseal tritoral rods, and almost 20 frontal tenacular denticles. On the basis of size and morphological features, the material represents different ontogenetic stages. The mandibular tooth plate is the smallest of a chimaeroid that has been described up to date. It is identified as an embryonic tooth plate, in which the pleromic tissue of the tritoral pads still is covered completely with dentine. The fragmentary symphyseal tritoral rods, which are almost as large as the tooth plate, and the frontal tenacular spines come from adults. The mandibular tooth plate from Spain described in this study most probably represents an embryonic stage of Ischyodus egertoni. The differences in tritor number, arrangement, and morphology are related to the early ontogenetic stage of the specimen. We thus tentatively assign the tooth plate, tritoral rods, and tenacular denticles to this species. Ischyodus egertoni was a common species inhabiting the epicontinental seas covering wide areas of England and France during the Kimmeridgian. The Spanish record extends the known geographic distribution of European Late Jurassic chimaeroids southwards.

The Manning Canyon Shale Formation (upper Mississippian/lower Pennsylvanian) of Central Utah is well known for its diverse flora, but not its vertebrate fauna. The previously described vertebrates from the Manning Canyon Shale are a tooth from a cladodont shark, an acanthodian, and a microsaur. Here, the known vertebrate diversity is expanded with the description of early actinopterygian fishes. The actinopterygian ichthyofauna consists of two new species of ‘palaeoniscoid’ fishes, Spinofacia pectinatus and Guntherichthys lehiensis, and a new aeduellid species, Bourbonnella jocelynae. Spinofacia pectinatus is characterized by the presence of extra lateral gulars (the only documented case outside the Bear Gulch Limestone of Montana) and extra-oral denticles on various dermal bones of the skull, whereas Guntherichthys lehiensis is distinguished by scales with slightly rounded posterior margins. The new aeduellid, Bourbonnella jocelynae, is now the earliest known aeduellid and the second occurrence of this genus and family in North America. Its discovery supports biogeographical and paleoecological findings of a marine connection between North America and Europe. The previously proposed freshwater paleoenvironment of the Manning Canyon Shale Formation is called into question, especially when the ichthyofauna of the site is considered. It is also important to note that although not many actinopterygian specimens have been collected from the Manning Canyon Shale, those that have reveal a previously unknown diversity.

Recent work in the Late Devonian (Frasnian) Fram Formation of Ellesmere Island, Nunavut, Canada, has produced the first North American record of Laccognathus (Sarcopterygii, Porolepiformes), a taxon previously known only from Latvia and Russia. Represented by a large sample that includes cranial material from 22 individuals, Laccognathus embryi, sp. nov., is uniquely diagnosed by features including the absence of marginal teeth on coronoids 1 and 2, and the lack of a fifth posthyal branchial arch. The large sample allows detailed morphological description of many parts of the cranial skeleton, including the dermal skull, braincase, palatoquadrate, and branchial skeleton. Comparison of the faunas from the Fram Formation in Nunavut, the Escuminac Formation in Quebec, and the Lode and Gauja formations of Latvia confirms a Laurussian (Euramerican) biogeographic province in the late Middle/early Late Devonian and may indicate tolerance of some forms to varied salinities. A cranial reconstruction of the new taxon reveals a wide head with a width-to-length ratio of approximately 2:1, a large spiracular opening, a small orbit, and a lower jaw in which much of the labial surface faced ventrally. The cranial morphology suggests a benthic animal reliant on sit-and-wait predation.

Tambaroter carrolli is a new genus and species of medium-sized ostodolepid ‘microsaur’ from the Lower Permian Tambach Formation, lowermost formational unit of the Upper Rotliegend, Thuringia, central Germany. Based on a single skull, it is the first ‘microsaur’ to be described from this formation and the first vertebrate fossil known from the Tambach Formation outside of the well-known, nearby Bromacker locality. It possesses typical ostodolepid features, including presence of a recumbent snout, ventral embayment of the cheek, a notch in the posterolateral margin of the tabular, and a well-developed retroarticular process. It can be distinguished from other ostodolepids by proportional characters and bones forming the cheek embayment rim. The presence of Tambaroter in Europe, as the first ostodolepid known from outside of the midcontinent of North America, indicates that the geographic occurrence of this family was more widespread than previously known.

The first fossil occurrence of the genus Lepidobatrachus is reported. The specimen comes from the Farola Monte Hermoso locality (Buenos Aires Province, Argentina), more specifically from the early Pliocene levels of the Monte Hermoso Formation. The specimen belongs to the living species L. laevis, a frog that currently inhabits the Chacoan region of northern Argentina, Paraguay, and Bolivia. The presence of this anuran represents the southernmost record for the genus Lepidobatrachus, and is in agreement with previous hypothesis suggesting that during the Pliocene the climatic environmental conditions of the southern Pampas were likely those of the modern Chacoan region. The disjunct distribution of extant L. laevis suggests that the retraction of Chacoan areas to the north modified the former distribution of this taxon, and that its current geonemy may represent relics of a formerly more extensive geographic distribution.

A new ophthalmosaurid ichthyosaur, Sveltonectes insolitus, gen. et sp. nov., is described from a sub-complete and three-dimensionally preserved specimen from the late Barremian of western Russia. This new taxon is supported by 11 cranial, dental, and postcranial autapomorphies, and is also characterized by features previously considered as autapomorphic for some other Ophthalmosauridae, such as a processus narialis on the prefrontal and relatively long hind fins with pre- and postaxial accessory digits. We conducted a new phylogenetic analysis of Thunnosauria, which supports a ‘Stenopterygius’ origin for Ophthalmosauridae. Sveltonectes is regarded as the sister taxon of Aegirosaurus, which shares a similar skull roof construction. Contrary to most other Cretaceous ichthyosaurs, Sveltonectes is characterized by delicate and sharply pointed teeth, confirming that the ophthalmosaurids were ecologically highly diversified during the Early Cretaceous.

Currently known from the early Campanian to late Maastrichtian, Prognathodon constitutes a group of mosasaurine mosasaurs that typically possessed massive jaws. Only four articulated skulls are known to date and the information concerning their postcrania remains minimal. Moreover, the early to middle Campanian specimens of the taxon are extremely rare and fragmentary. Two new specimens of Prognathodon overtoni from the early late Campanian (ca. 74.5 Ma) Bearpaw Formation exposed near Welling, southern Alberta, Canada, provide the first fully articulated skeletons of the genus. Detailed morphological assessment of these and pre-existing specimens indicates that many cranial characters are shared between P. overtoni and the generic type P. solvayi from the early Maastrichtian, including (1) short premaxillary-maxillary suture; (2) short triangular frontal with marked anterior constriction; and (3) distinct, blind-ended median opening on medullary floor of basioccipital. These are interpreted as generically diagnostic characters, and the first character in particular distinguishes Prognathodon from Liodon and other long-snouted mosasaurines. The postcranium of P. overtoni is lightly built, and differs very little from that of Clidastes, a basal mosasaurine. Marginal teeth are carinate with fine crenulations, indicating their proposed opportunistic predatory behavior. Additionally, most of the fully erupted teeth exhibit a similar degree of apical wear, which is interpreted as indicating that the taxon regularly handled prey items that involved crunching. To augment these dietary inferences, gut contents from one of the new specimens include fragments of a large and a small fish, a sea turtle, and possibly a cephalopod.

Anchiceratops is a chasmosaurine ceratopsid from the Upper Cretaceous Horseshoe Canyon Formation (HCF) of Alberta. It is distinguished primarily by its unique parietosquamosal frill ornamentation and possibly by the presence of a ventrally flexed olfactory bulb of the brain. Although Anchiceratops is known from at least ten partial skulls, only two of these have been formally described. These skulls are not stratigraphically segregated, but they differ markedly in their proportions (e.g., supraorbital horncore and frill dimensions), causing previous authors to account for this disparity with reference to either interspecific or sexual differences. Both of these hypotheses assume that variation in Anchiceratops is dimorphic; however, this assumption has never been tested with reference to all available material. The present study describes all material from the HCF that can be positively attributed to Anchiceratops, and tests the assumption of dimorphism by subjecting this material to a series of morphometric analyses. We find no compelling evidence for dimorphism in Anchiceratops, although sample size is still too small for convincing statistical support. We conclude that there is a single, variable species of Anchiceratops, A. ornatus. Average sedimentation rates for the HCF suggest that A. ornatus is a particularly long-lived species compared with other ceratopsids (∼1.5–2.0 Ma), and the paleoecological implications of this are discussed. A cladistic analysis that includes the new data presented here indicates that Anchiceratops is more closely related to Chasmosaurus than to Triceratops, in contrast with previous studies.

Complete sauropod pedes are rare in the fossil record, which has limited their use in systematics. We describe a nearly complete, large sauropod pes from the Maastrichtian-age Naashoibito Member of the Kirtland Formation of New Mexico, U.S.A., that bears synapomorphies of some eusauropod clades, such as the presence of metatarsal I with a wide shaft and laterally deflected pedal unguals. Novel pedal characters presented herein, such as the presence of an embayment on the proximomedial corner of metatarsal IV, suggest that the Naashoibito specimen likely belongs to a titanosauriform. Based on its provenance, the Naashoibito specimen likely belongs to the derived titanosaur Alamosaurus sanjuanensis, which is the only recognized Late Cretaceous titanosaur in North America. However, formal referral to Alamosaurus awaits discovery of overlapping materials with the holotype or definitively referred remains. The holotypic scapula of Alamosaurus sanjuanensis is diagnostic, providing a basis for referral of some other Maastrichtian North American titanosaur specimens to the genus. Confirmation of these referrals and the description of the pes presented herein augment the data relevant to the systematic problems that have historically surrounded Alamosaurus.

Psilopterus lemoinei, the largest species in this genus, was a small terror bird weighing 8–9 kg, and was a ground bird with functionally tridactyl feet. New remains of this phorusrhacid, including an exceptionally preserved anterior part of a skull recovered from the Patagonian Killik Aike Norte locality (Santa Cruz Formation, late early Miocene), is now available for study. The main purpose of this paper is to provide a detailed morphological description of Psilopterus lemoinei. The new fossils show for the first time that the internal structure of the beak is hollow and reinforced with thin-walled trabeculae. The absence of zona flexoria palatina and zona flexoria arcus jugalis are key features related to the evolution of cranial akinesis. Homologies of the narial and fenestra antorbitalis boundaries have been clarified. Our re-examination allows the establishment of primary osteological homologies useful in comparative anatomy, functional morphology, and phylogenetic studies.

A redescription of the bones of Tyto sanctialbani from its type locality of La Grive-Saint-Alban (Isère, France) is presented. Tyto sanctialbani is the oldest species of the genus Tyto known so far, and the possible ancestor of the succeeding European taxa. Tyto sanctialbani is reported from Miocene localities in France and elsewhere in Europe and is cited as a well-known species, although it has never been described in detail. This work is based on morphological description of the type series in the Natural History Museum, London, with the selection of a lectotype and paralectotypes. In addition, we describe other fossil bones from La Grive-Saint-Alban housed in the Natural History Museum, London, in the Muséum d'Histoire Naturelle, Lyon, and in the Faculté des Sciences de Lyon (= Université Claude Bernard Lyon 1, Villeurbanne), France. The detailed morphology of all the major long bones of Tyto sanctialbani, some of them previously unknown for this species, is presented. Tyto sanctialbani is compared with all the European fossil species of the genus, and in detail with the extant Tyto alba, the species that is closest in size. The validity of Tyto campiterrae is discussed and confirmed, whereas Miocene records of T. balearica should be considered as invalid.

A new genus and three species of parrot (Psittaciformes, Strigopidae, Nestorinae) are described from the early Miocene (19–16 Ma) St Bathans Fauna of Otago, New Zealand, based on 85 fossils as follows: Nelepsittacus minimus (17), N. donmertoni (60), and N. daphneleeae (6), with two additional fossils representing a fourth unnamed taxon. These taxa range from small parrots approximately the size of Cyanoramphus species to one as large as the living Nestor notabilis. Apomorphies in the coracoid, humerus, tibiotarsus, and tarsometatarsus ally Nelepsittacus with Nestor and exclude a close relationship with Strigops, the other endemic genus assumed to have had a long history in New Zealand. With only nestorine parrots represented, the St Bathans Fauna has nothing in common with the Australian psittaciform fauna, in which cacatuids and a diversity of psittacid genera exist. These data add to the growing body of evidence that the New Zealand terrestrial vertebrate fauna, at a time minimally 3 Ma after the maximal marine inundation of Zealandia in the late Oligocene, was highly endemic, with no close relationship to the closest faunas in Australia. This high degree of endemism strongly suggests that the Zealandian terrestrial biota persisted, at least in part, through the Oligocene highstand in sea level.

Griphotherion peiranoi, a new genus and species of notoungulate from northwestern Argentina, is presented here. The material studied consists of a nearly complete skull and part of the postcranial skeleton, recovered in the Lumbrera Formation (Eocene) at the locality of El Simbolar (Salta Province, northwestern Argentina). The specimen was evaluated in terms of a matrix of 28 craniodental characters and compared with 11 typotherian genera. Additionally, characters of the new taxon were compared to those included in a previously published data matrix that includes several native South American ungulates. The particular features present in the specimen indicate unequivocally that this is a new notoungulate taxon; nevertheless, due to its distinctiveness, we opted not to place the novel taxon in any of the known families of Notoungulata. The results of the analyses performed indicate that G. peiranoi is closely related to Mesotheriidae, Hegetotheriidae, and Archaeohyracidae. These families represent the ‘rodent-like’ notoungulates that evolved during the Late Paleogene and the Neogene. This new record contributes to our knowledge of the Eocene notoungulate fauna of northwerstern Argentina. It also supports the broader perspective that this region played an important role as an area of origin and diversification for several lineages of this remarkable order of endemic South American ungulates.

A dentary from the Laventan SALMA (middle Miocene) of Quebrada Honda, Bolivia, recognized as a new, small member of Megatherioidea (Hiskatherium saintandrei, gen. et sp. nov.), is reported. This taxon is clearly distinct from Nothrotheriidae and Megalonychidae and has affinities with Hapalops and Xyophorus. It is characterized by m1–m4 without diastema; strong hypsodonty (HI = 0.93); m1–m3 constituted by two transverse lophids separated by a deep, transverse, and labially open valley; m4 round with distal lophid mesiolingually-distolabially extended and without vertical groove; m2–m3 with lingual and labial vertical grooves; and the posteroventral margin of symphysis located anteriorly to m1. Although Hiskatherium and Diabolotherium have a similar dental formula, the ‘megatheriine-shaped’ teeth of Diabolotherium do not support a close phylogenetic relationship between Hiskatherium and Diabolotherium. Their dental formulae suggest that both genera were selective feeders, capable of consuming tough items. Hiskatherium, like most other sloths, has lower molariform teeth that have a mesial and a distal lophid; the former has a mesial cuspid ‘A,’ located at the center of the mesial lophid, and the latter has distolingual (‘B,’ or lingual) and distolabial (‘C’) cuspids at each end. This terminology permits a straightforward nomenclature based on cusp/cuspid position and facilitates comparisons among Tardigrada.