The oldest reported fossil record of Delphinidae is from the late Miocene (11 Ma) of California. Reliable Miocene fossil delphinids, however, are few. Eodelphis kabatensis from the upper Miocene Mashike Formation (8.5–13.0 Ma), Hokkaido, northern Japan, is the oldest described Miocene delphinid including a skull. Therefore, this species is a significant clue to understanding the early evolutionary history of Delphinidae. The original taxonomic assignment of this species within the genus Stenella is questionable; thus, we propose a new combination for the species, Eodelphis kabatensis Horikawa, 1977. Eodelphis is a basal delphinid, and comprehensive morphological cladistic analysis, including molecular topological constraints, supported this taxonomic revision. Paleobiogeographic analyses based on the present morphological cladistic analysis and analysis under the molecular constraints suggest that the origin and early diversification of Delphinidae occurred in the middle Miocene Pacific Ocean or elsewhere, respectively.

A collection of over 550 elasmobranch teeth (Family Lonchidiidae) were obtained from fresh water fluvial deposits of the Middle—Upper Triassic (Ladinian—Carnian) Paramillo Formation, in northwestern Mendoza Province, Argentina. The new hybodontid species, Lonchidion paramilloensis, sp. nov., solely based on teeth, is within a 20-m-thick interval containing black shale interbedded with andesitic sills and intercalated with lensoidal calcarenites. The teeth have a characteristic labial peg with an accessory cusplet and a low gracile crown that is narrower labiolingually and more elongate laterally. The teeth are similar to some North American Late Triassic and Late Cretaceous species of the genus Lonchidion (e.g., L. humblei, L. griffisi, L. selachos), but are distinct in having a low primary cusp, up to seven pairs of lateral cusplets, a rounded-triangular-shaped labial peg with one accessory cusplet, and an absence of other crown ornaments. Color analyses of upper tooth crowns indicate an ichthyolith alteration index (IAI)/conodont alteration index (CAI) value of 6.0–6.5 (360–610°C). Considerable pitting and alteration of specimens indicates thermal alteration to 610° C and (or) chemical alteration.

A new temnospondyl specimen from the Rio do Rasto Formation (late Permian, Paraná Basin) of south Brazil is composed of a left mandible, right pelvis, femur, tibia, and fibula. Preserved lower jaws are rare for Australerpeton cosgriffi, and the weak ossification of the temnospondyl postcranium renders their preservation generally uncommon. A detailed comparative description of the material allowed its assignment to Australerpeton cosgriffi, and yielded new information about the morphology of mandible, pelvis, and hind limb of that taxon. This long-snouted temnospondyl has uncertain affinities and has been assigned either to stereospondyl Rhinesuchidae or to archegosaurid Platyoposaurinae. Reassessment of the phylogenetic placement of Australerpeton cosgriffi, with information drawn from the new specimen, confirms a basal stereospondyl position, between Peltobatrachus pustulatus and Rhinesuchidae. The synapomorphies shared with other stereospondyls include tabular and exoccipital contacting in the paroccipital process; parasphenoid articulates with corpus of the pterygoid forming a broad contact along the lateral margins of the parasphenoid plate; internal carotid passes through the dorsal surface of the parasphenoid plate; and parasphenoid denticles field enlarged to a transverse ‘belt’ extending between the pterygoidparasphenoid articulations. Accordingly, Australerpeton cosgriffi represents one of the first stereospondyls, and the oldest long-snouted member of the group. The Paraná Basin can be included within the stereospondyl ancestral range, and dispersion and diversification of this clade appears to have happened before the Permo—Triassic boundary.

We describe a new capitosauroid temnospondyl, Antarctosuchus polyodon, gen. et sp. nov., on the basis of a large and relatively complete skull from the upper Fremouw Formation of Antarctica. The new species is characterized by its possession of numerous, extremely small maxillary, palatine, and ectopterygoid teeth, a dental pattern that suggests specialization on small prey items, possibly invertebrates. The taxon is also characterized by a parachoanal tooth row that extends far posterior to the choana and occipital condyles set close to the midline. A combination of features, including a flat skull and low occiput together with well-developed sensory canals, suggests an aquatic lifestyle. We address the phylogenetic relationships of Antarctosuchus by adding it to a recent cladistic analysis of Capitosauria. The revised data set includes 27 taxa and 53 characters. The results of this analysis place Antarctosuchus within a clade of derived Triassic stereospondyls as the sister taxon to Paracyclotosaurus crookshanki from the Triassic Denwai Formation of India. To date, the upper Fremouw Formation has yielded two endemic temnospondyl species (viz., Kryostega collinsoni and Antarctosuchus polyodon), although indeterminate remains referred to benthosuchids and a cranial fragment assigned to Parotosuchus sp. have also been noted. In contrast to the broadly distributed therapsid taxa recognized from the Middle Triassic of Antarctica (e.g., Cynognathus, Diademodon), the temnospondyl fauna suggests more limited interchange with other coeval southern Pangean basins (e.g., Karoo, Luangwa, Ruhuhu, Waterberg).

A review of the remains of mosasaurine mosasaurs from the upper Campanian—Maastrichtian of Italy is provided. The first discoveries of mosasaur material from Italy are represented by a series of isolated teeth from the Scaglia Rossa Formation north of Vittorio Veneto (late Campanian). These teeth show some similarities to Prognathodon, Liodon, and Eremiasaurus, but are not identical and probably represent a new taxon. A partial mosasaur skull found south of Reggio Emilia in 1886 is potentially a new species of Mosasaurus, although more material is needed to support this possibility. This specimen is temporarily referred to M. cf. hoffmanni. A second fragmentary mosasaur skull was accidentally discovered in 1892 north of Verona during the demolition of a school (inside one of the building stones). Based on its general morphology, size, and dentition, this second specimen can be considered as very closely related to M. hoffmanni, but its older age (early—middle Maastrichtian) suggests that it likely represents a new species of Mosasaurus. We refrain from erecting new taxonomic names for these specimens pending the discovery of new, more complete material upon which satisfactory diagnoses can be based. The paleobiogeographic distribution of Mosasaurus hoffmanni, M. cf. hoffmanni, M. beaugei, Liodon, and Prognathodon is reviewed briefly.

In this paper, we describe a new species of a giant tortoise, Cheirogaster bacharidisi, sp. nov., from the Pliocene (Gonia Formation) of western Chalkidiki Peninsula, near Thessaloniki, Greece. The specimens constitute the most complete giant tortoise found to date in Greece, and provide materials for direct comparison with other described European forms. We assign it to the genus Cheirogaster, as opposed to Centrochelys, based upon the convex dorsal surface of the epiplastron. Direct comparison with material from Europe shows that it differs from other giant tortoises attributed to Cheirogaster mainly in cranial and plastral morphology. Exceptional postcranial preservation allows the description of many skeletal elements, previously unknown or poorly described for Cheirogaster, as well as for a reappraisal of the previously published specimens from Greece.

A new taxon of peirosaurid crocodyliform, Rukwasuchus yajabalijekundu, gen. et sp. nov., is described on the basis of a well-preserved partial skull from the middle Cretaceous Galula Formation exposed in southwestern Tanzania. The skull is distinguished from those of other crocodyliforms by the presence of a mediolaterally narrow, elongate, and septate internal narial fenestra (choana) located anteriorly on the pterygoid; a markedly depressed posterior border of the parietal, excluding the supraoccipital from the dorsal cranial table; and a ventrally directed descending process of the postorbital with a well-developed posteroventral process. The lateral surface of the braincase is exquisitely preserved and includes a well-developed laterosphenoid bridge dividing the foramina for the three primary branches of the trigeminal nerve. In overall morphology, the holotype skull and isolated teeth compare closely with Hamadasuchus rebouli from the middle Cretaceous Kem Kem Beds of Morocco. Reevaluation of the problematic putative African peirosaurid taxa Stolokrosuchus lapparenti and Trematochampsa taqueti reveal a number of derived cranial characters shared with Peirosauridae and Araripesuchus. A close relationship between Rukwasuchus and other African members of Peirosauridae is supported by a parsimony analysis of Crocodyliformes. As the only known sub-Saharan peirosaurid from Africa, Rukwasuchus represents the only link between middle Cretaceous southern vertebrate faunas and much more abundant, taxonomically diverse, and potentially penecontemporaneous faunas from northern Africa.

A new pterosaur fossil with an articulated skull and fragmentary postcranial skeleton was collected from the Jurassic Tiaojishan Formation of Linglongta, western Liaoning, China. Its configuration shows an affinity with the Scaphognathus-like Jianchangnathus robustus, which was reported from the same region and horizon. The fossil reveals new cranial morphology: a convex dorsal margin of the skull, antorbital fenestra completely posterior to the naris, a long maxillary process and short quadratojugal process of the jugal, and jaw articulation above the midheight of the mandible; the first upper tooth close to the snout tip, the two anterior-most upper teeth tightly arranged, and the fifth upper tooth positioned at the level of the anterior margin of the naris. Recent discoveries of non-pterodactyloids from the Tiaojishan Formation of northeastern China exhibit a high taxonomic diversity comparable to those in the Solnhofen Limestone. Therefore, as a significant pterosaur assemblage before the Solnhofen Limestone, the Tiaojishan Formation provides a new perspective in understanding the evolution and diversity of the non-pterodactyloids.

Here we describe Vahiny depereti, gen. et sp. nov., a new titanosaur dinosaur from the Upper Cretaceous Maevarano Formation of northwestern Madagascar. Vahiny is distinguished from other titanosaurs by characteristics of the basal tubera, basipterygoid processes, parasphenoid, and cranial nerve foramina. Diagnostic cranial material of Vahiny formalizes the long-standing hypothesis that two titanosaur genera were present in the Late Cretaceous of Madagascar. The other titanosaur, Rapetosaurus krausei, is the most common dinosaur in the fauna and is known from hundreds of bones, including multiple partial skeletons and skulls. In contrast, non-Rapetosaurus elements are extremely rare. Of these elements, which have been called ‘Malagasy Taxon B,’ we identify a partial braincase as the holotype of Vahiny depereti. Although Vahiny and Rapetosaurus coexisted on the island of Madagascar, differences in their braincases indicate that they are not closely related to one another. Instead, Vahiny is most similar to Jainosaurus from the Late Cretaceous of India, and shares similarities with the South American taxa Muyelensaurus and Pitekunsaurus.

Here we describe a new partial sauropod skeleton from the late Kimmeridgian (Late Jurassic) of the Lourinhã Formation, central west Portugal. The closely associated specimen comprises a complete tooth (with root), a fragment of cervical neural arch, an anterior chevron, and an almost complete right pectoral girdle and forelimb. The new sauropod, Zby atlanticus, n. gen. et sp., can be diagnosed on the basis of four autapomorphies, including a prominent posteriorly projecting ridge on the humerus at the level of the deltopectoral crest. Nearly all anatomical features indicate that Zby is a non-neosauropod eusauropod. On the basis of several characters, including tooth morphology, extreme anteroposterior compression of the proximal end of the radius, and strong beveling of the lateral half of the distal end of the radius, Zby appears to be closely related to Turiasaurus riodevensis from approximately contemporaneous deposits in eastern Spain. However, these two genera can be distinguished from each other by a number of features pertaining to the forelimb. Whereas previously described Late Jurassic Portuguese sauropods show close relationships with taxa from the contemporaneous Morrison Formation of North America, it appears that turiasaurians were restricted to Europe. All adult sauropods recovered in the Late Jurassic of Portugal thus far are very large individuals: it is possible that the apparent absence of small- or medium-sized adult sauropods might be related to the occupation of lower-browsing niches by non-sauropods such as the long-necked stegosaur Miragaia longicollum.

The description and comparison of the posterior braincase of Nothronychus mckinleyi (MSM P-2117) from the Upper Cretaceous (Turonian) Moreno Hills Formation of east-central New Mexico is updated. As a result of the enlarged basicranial pneumatic system, this region of the skeleton has undergone extensive rearrangement of the cranial nerves and blood vessels from the plesiomorphic theropod condition. Nothronychus and Falcarius possessed a number of avian-associated characters or avian-trending characters in the braincase and endocranium characteristic of highly derived coelurosaurs. These traits, in some cases hypothesized, include the posterior endocranium nearly filled with nervous tissue, a laterally directed enlarged optic tectum, an enlarged flocculus, an intracranial trigeminal ganglion, and the abducens canal entering the endocranium separate from the infundibulum with no associated cavernous sinus. The angle of the occipital plate with the basal plate of the basicranium appears to be perpendicular and, therefore, intermediate between more basal theropods and extant birds. However, the posterior endocranial cavity does not appear flexed, which would result in a posteroventral rotation of the endocranial cavity in Nothronychus, a character also seen in the Cretaceous hesperornithiform bird Enaliornis and in contrast to extant birds. Therefore, the evolution of the coelurosaurian brain and braincase was trending in an avian direction before the rest of the skeleton. The results presented here support the model that therizinosaurs possessed weak bite forces as compared to obligatory carnivorous theropods.

We describe a new isolated tarsometatarsus from the Early Cretaceous (Barremian—Aptian) Ilek Formation Shestakovo-3 locality in western Siberia. The new specimen represents a new taxon, Evgenavis nobilis, gen. et sp. nov., significantly increasing the Mesozoic avifauna from Russia. The specimen shares morphologies with a number of basal ornithothoracine taxa, but shows most similarity to the basal pygostylian Confuciusornis sanctus, the oldest known beaked bird and most common taxon from the Yixian Formation. Evgenavis may represent the first record of Confuciusornithiformes outside of the Jehol Group and its equivalent deposits. However, this is not supported by cladistic analysis, which weakly resolves the new species and Mystiornis both within the diverse Enantiornithes, indicating that additional material is required to assess the systematic position of Evgenavis nobilis (Aves incertae sedis). The three-dimensional preservation of the specimen allows for a partial reconstruction of the pedal musculature, revealing a primitive stage in the evolution of the neornithine condition.

We describe a new enantiornithine bird, Fortunguavis xiaotaizicus, gen. et sp. nov, from the Lower Cretaceous lacustrine deposits of the Jiufotang Formation in northeastern China. The new taxon has a strongly dorsoventrally bowed furcula indicating that enantiornithines evolved furcular morphologies in parallel with ornithuromorphs. The new specimen has very robust limbs compared with other enantiornithines and has an unique foot morphology with metatarsal II much shorter than metatarsal IV, robust pedal digits, and strongly recurved pedal unguals. Although recurved unguals characterize Enantiornithes, the extreme curvature present in Fortunguavis suggests scansorial specialization in this species. These features hint at a unique ecology for this taxon and further increase the known diversity of body plans in Early Cretaceous enantiornithines.

The Sparassodonta (Mammalia, Metatheria) are a group of carnivorous mammals that dominated the macropredatory guild of South America during the Cenozoic. Here, we describe a new sparassodont based on a single specimen from the middle Miocene Quebrada Honda local fauna of southern Bolivia. This specimen (UF 27881) does not clearly correspond to any major sparassodont group (e.g., Hathliacynidae, Borhyaenidae, etc.) and represents a morphotype previously unknown among the Sparassodonta. UF 27881 is distinguished from other sparassodonts by its short, broad, borhyaenid-like rostrum and small size, among other features. However, we decline to coin a new name for UF 27881 due to the fragmentary nature of this specimen and the absence of most of its dentition. This specimen suggests that the appearance of the Sparassocynidae and several hypercarnivorous didelphid taxa (including Thylophorops, Thylatheridium, Lutreolina, and Hyperdidelphys) represent an evolutionary response to the decline in small, predatory sparassodont taxa during the late Cenozoic. This study documents new morphological diversity among the Sparassodonta and highlights the value of fossils from traditionally undersampled parts of South America.

Octodontoidea is the most diverse caviomorph clade presently represented in South America by Octodontidae, Echimyidae, and Abrocomidae. Some evidence suggests that in the past they were taxonomically even more diverse, including several independent lineages with no modern representatives, sometimes considered as families. One of them is Acaremyidae, known until now from the Colhuehuapian—Colloncuran (early to early—middle Miocene) of Patagonia. Here we describe a new octodontoid rodent from the Deseadan (late Oligocene) of Scarritt Pocket (Patagonia): Changquin woodi, gen. et sp. nov. Cladistic analysis indicates that the new species is an acaremyid related to the Santacrucian (early Miocene) Sciamys. Acaremyidae was recovered as a monophyletic group. C. woodi, gen. et sp. nov., the oldest representative of Acaremyidae, extends the family biochron back to the late Oligocene, and indicates that acaremyids differentiated before the Deseadan. C. woodi represents the first Deseadan octodontoid displaying protohypsodont cheek teeth, showing that the Deseadan was a period of important diversification for octodontoids, as it was for the cavioids. C. woodi adds a new element to the faunal differences observed between Patagonian and Bolivian Deseadan faunas. A new U-Pb laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) date (27.17 ± 0.54 Ma) for Scarritt Pocket is provided.

In the present work we conduct a comparative study of the cranial and dental samples of the early machairodontine Machairodus aphanistus from the Vallesian (MN 10) sites of Batallones-1 and Batallones-3 (Torrejón de Velasco, Madrid, Spain). These sites, which have yielded the most abundant and complete samples of this felid, show interesting differences in faunal composition and age, thus providing a unique opportunity for both qualitative and quantitative comparisons between two populations of the same species. The study reveals differences in a number of cranial features, and statistically significant differences in teeth size and proportions. Although probably not enough to support a separation at the species level, these observations fit well with the morphological evolution of the lineage leading towards more derived forms such as the Turolian Amphimachairodus giganteus.

Shanshenmiaozui in the Nihewan Basin of China is the locality that has produced the richest sample of Coelodonta nihowanensis material, including a nearly complete juvenile skull and mandible as well as various other cranial, mandibular, and postcranial bones. All of the cranial and mandibular specimens belong to individuals around 1.5 years old. On the basis of both qualitative morphological characters and Osteometric measurements, the new specimens can be provisionally referred to the species Coelodonta nihowanensis. They also fall within the range of variation seen in late Pleistocene Coelodonta antiquitatis, but are distinct from this species in having developed cingula, relatively low-crowned teeth either with or without very thin cement on the surface, vestigial lower incisors, less backward-curved protolophs, and more slender limb bones. The newly discovered juvenile skull of Coelodonta nihowanensis from Shanshenmiaozui represents the only known complete juvenile skull of an early member of Coelodonta, and therefore has great significance for understanding the development and evolution of the genus. Extensive comparisons with all other Coelodonta species, and with extant rhinoceroses, indicate that the new specimens are much more similar to the true woolly rhino Coelodonta antiquitatis than to any other taxon.