Giant flightless fowl (Aves, Dromornithidae) similar to the Northern Hemisphere gastornithids and weighing up to 350–650 kg evolved on Gondwana and existed in what is now Australia from the Eocene to the late Quaternary. Understanding cranial morphology of dromornithids has until now been based almost wholly on species of Dromornis, with that of species in three other genera either previously unknown or very fragmentary. Here we rectify this deficiency and describe a well-preserved cranium from the middle Miocene Bullock Creek Local Fauna referred to Ilbandornis woodburnei, rich, fragmentary crania, quadrates, pterygoids, and mandibles for the Oligo-Miocene Barawertornis tedfordi Rich, and additional material of the species of Ilbandornis. The morphological similarity of this cranial material suggests that the emusized B. tedfordi is a smaller precursor to and differs little from species of Ilbandornis. Dromornis murrayi, n. sp., from late Oligocene—Early Miocene sites at Riversleigh, based on cranial and postcranial elements, is the oldest and smallest species in its genus. Placed in the context of other data, these observations suggest that the dromornithids comprised only two lineages throughout the Oligo-Miocene. The Barawertornis-Ilbandornis lineage attained maximum diversity in the middle Miocene Bullock Creek and late Miocene Alcoota local faunas (LF), with two species in each, but the Dromornis lineage seems to have been monotypic throughout its temporal range. The low diversity of these giant galloanseres in Australia mirrors that of the giant herbivorous ratites (ostriches and kin), which similarly have low diversity where they coevolved with diverse mammalian faunas.

A new genus of Oligo-Miocene kangaroo (Macropodiformes), Cookeroo, and two new species, Cookeroo bulwidarri and C. hortusensis, are described from the Riversleigh World Heritage Area, northern Australia. Species of Cookeroo are distinguished from other basal macropodids by possessing a unique combination of characters including an expanded masseteric canal confluent with the mandibular canal that extends to below m1, a sinuous i1 with enamel on the buccal surface only and with dorsal and ventral flanges present, a dentary with a marked inflection of the ventral border below m3, bilophodont molars, and an elongate third premolar. We assess the phylogenetic relationships of the genus using a combination of two previously published morphological matrices. Our analysis recovers Cookeroo species as early-branching members of a clade that also contains macropodines, sthenurines, and lagostrophines.

The ‘Swami's Point local fauna,’ recovered from the Delmar Formation in coastal San Diego County, California, U.S.A., represents the first documented Bridgerian vertebrate assemblage in this region. The Delmar Formation is chronologically constrained (ca. 48-47 Ma) on the basis of paleomagnetic polarities, the superposition of marine strata containing nannofossils of the CP 12b subzone, and occurrences of the Bridgerian index taxa Trogosus castoridens and Hyrachyus modestus. The specimen of Trogosus (SDSNH 40819) is assigned here to the genotypic species, T. castoridens, hitherto known only from incomplete dentaries from the middle Bridgerian (Br2) Bridger Formation, Green River Basin, Wyoming. The present specimen is represented by a skull with diagnostically short rostrum, incomplete stylohyoids, posterior parts of both dentaries, and cervical vertebrae from a single individual. This is one of the most anatomically informative specimens of Trogosus and for the first time provides details of the basicranial region in the order Tillodontia. A well-preserved occipitomastoid process is clearly composed of the mastoid process of the petrosal and the paracondylar process of the exoccipital. Cranial comparison reveals greater similarity with T. hyracoides from the Bridger Formation than with T. grangeri and T. hillsii from the Huerfano Basin, Colorado. The results of a phylogenetic analysis suggest that the short-faced condition evolved at least twice in species of Trogosus and leads to recognition of two sympatric trogosine species pairs: T. hyracoides T. castoridens from the Green River Basin and T. grangeri T. hillsii from from the Huerfano Basin.

Unusual shovel-tusked gomphothere material from the late Clarendonian Black Butte Local Fauna (Juntura Formation, Oregon), including a lower tusk, partial upper tusk, and two mandibles including a second and a third molar, has been described and referred to Platybelodon. Platybelodon has the following diagnostic characteristics: molars strongly double-trefoiled; third molar with five lophs; lower tusks short with broad and very flat profiles lacking significant dorsoventral curvature; and lower tusks lacking obvious lamination but instead filled with small, short dentinal rods. However, the Black Butte shovel-tusked gomphothere was referred to Platybelodon despite having the following conflicting features: molars with weakly developed single trefoiling; third molar with only four lophids (the fourth little more than a talonid); broad, moderately flattened, relatively elongated lower tusk with strong dorsal curvature; and lower tusk internal structure showing lamination rather than dentinal rods. In addition, both the upper and lower tusks of the Black Butte shovel-tusker have prominently corrugated enamel cortices, a feature unknown in any other gomphothere. Thus, given the lack of a single clear-cut shared diagnostic feature and the large number of differences between these taxa, the identification of the Black Butte shovel-tusker as Platybelodon must be refuted. Refutation of the Platybelodon identification requires an alternate identification to be made for the Black Butte shovel-tusker. No other known shovel-tusker genus, including the genera Amebelodon, Serbelodon, and Torynobelodon, possesses the unusual combination of tusk and cheek tooth features observed in this animal. Accordingly, it is here referred to a new genus and species, Eurybelodon shoshanii.

The shift to a cooler and drier climate through the Paleogene has been interpreted as the driver for changes in diversity and biogeographic distributions among mammalian taxa during the Eocene, leading to hypotheses of continued tropical climatic refugia in West Texas through the middle and late Eocene. However, the presence of ectothermic reptiles during that time has not been documented in detail and would potentially provide additional climatic indicators. We provide the first description of the herpetofauna from the Devil's Graveyard Formation (DGF), West Texas, the southernmost, wellsampled middle Eocene basin in North America. Specimens are derived from beds correlated with the Ui3 biochron of the late Uintan North American Land Mammal ‘Age’ (~45–40 Ma). We report the first amphisbaenians known from Texas, expanding our spatial and climatic understanding of rhineurid distribution, as well as the first glyptosaurine anguimorphs and alethinophidian snakes from the Purple Bench assemblage. These new amphisbaenians preserve a jugal posteriorly enclosing the orbit and an extremely short retroarticular process and are recovered in a clade comprising †Spathorhynchus, †Dyticonastis, †Ototriton, and †Hyporhina. The documentation of the amphisbaenians and other squamates provides biogeographic range extensions of these taxa to West Texas. Despite suggestions that West Texas was a middle and late Eocene climatic refugium for mammals adapted to subtropical forested environments, rhineurid amphisbaenians show a wide range of temperature tolerances up to the beginning of the Neogene.

A well-preserved fossil skull from a new locality in Jijiazhuang, Changle County, Shandong Province, China, is attributable to Plesiaceratherium gracile. Other rhinoceroses from the nearby Shanwang Basin of Linqu County, Shandong, formerly described as Aceratherium sp. and Plesiaceratherium shanwangensis are also referable to P. gracile. The new skull demonstrates the presence in P. gracile of the following characters: continuous labial cingula on lower cheek teeth; skull roof with nearly flat profile; and external auditory pseudomeatus ventrally closed, proceeding dorsocaudally in a shallow groove. Comparison of Plesiaceratherium with Brachypotherium pugnator Matsumoto, 1921, suggests that referral of the latter to Plesiaceratherium should be reconsidered. A phylogenetic analysis based on 314 characters scored for 39 terminal taxa places Plesiaceratherium mirallesi in a basal position within Rhinocerotidae, and recovers other species of Plesiaceratherium as a clade that is well separated from B. pugnator and is sister to the [Subchilotherium [Acerorhinus [Shansirhinus, B. pugnator [Chilotherium]]]] grouping. Based on this result and a reevaluation of the anatomy of ‘P.’ mirallesi, we propose that the genus Dromoceratherium should be revived to accommodate this species as D. mirallesi. The occurrence of P. gracile at Jijiazhuang indicates that the fossiliferous diatomaceous shales of this locality were deposited during the lower Miocene.

The evolution of the brain in rodents has rarely been studied from the perspective of the fossil record. Here we describe the first virtual endocast of a fossil rodent, pertaining to Ischyromys typus (ROMV 1007; Orellan North American Land Mammal Age [NALMA], Nebraska), and form comparisons with partial and complete natural endocasts pertaining to the same genus, and with the virtual endocast of a closely related extant rodent (Sciurus carolinensis; AMNH 258346). These data allow us to formulate the first hypotheses informed by the fossil record concerning changes in brain size and shape through time in rodents, and to make comparisons with other euarchontoglirans, including Primates. Ischyromys exhibits several aspects of brain morphology that can be inferred to be primitive, in part based on their presence in plesiadapiform primates (e.g., exposed midbrain), although variation exists within the genus Ischyromys with respect to the visibility of the inferior colliculi. There is some evidence that neocorticalization occurred in rodents through time but to a lesser degree than in Primates. Arboreality might be linked to increases in the encephalization quotient and specializations related to vision in rodents, which contrasts with the situation in Primates. Finally, Oligocene rodents had smaller olfactory bulbs compared with plesiadapiform primates from the Eocene, meaning that olfaction might have been less critical in the early evolution of rodents. These results show that the evolution of the brain in mammals does not always follow the same evolutionary trajectories and demonstrates the importance of considering ecological factors when looking at brain size.

Redescription of Hainosaurus bernardi Dollo, 1885a, from the early Maastrichtian of the Ciply Phosphatic Chalk of Belgium, results in a reassignment of the taxon to the genus Tylosaurus Marsh, 1872, because the genus Hainosaurus cannot be diagnosed independent of Tylosaurus. The diagnosis of Hainosaurus bernardi by Dollo, 1885a, is reviewed, and the two incomplete and poorly preserved specimens assigned to the taxon are compared with recognized species of Tylosaurus. Hainosaurus was originally diagnosed from characters of the jugal, quadrate, maxilla, premaxilla, frontal, parietal, and teeth. Here, we show that most of the characters of these elements are shared with the genus Tylosaurus, and that those that are not shared, but that are purported key diagnostic characters for Hainosaurus, are simply not preserved, or are too poorly preserved to support a differential diagnosis of H. bernardi at the generic level. The available data support the conclusion that Hainosaurus is a junior synonym of Tylosaurus because no anatomical features distinguish the former from the latter. The genus Tylosaurus occupied a wider geographic and temporal distribution than has been previously suggested, inhabiting the North Atlantic Circle Basin from the Turonian to the Maastrichtian. There are species-level features that support T. bernardi as distinct from other described species of Tylosaurus.

Pseudoseisuropsis wintu sp. nov. is described from cranial material that had formerly been designated as a paratype of the extinct Pseudoseisuropsis nehuen. Thorough comparisons were made between the cranial specimens ascribed to Pseudoseisuropsis and many extant furnariid species. This new species is lower Pleistocene in age and increases the known diversity of Pseudoseisuropsis to three species. Cladistic analyses were performed using 43 cranial characters and a backbone constraint based on a well-supported phylogeny from a recent molecular analysis. In the most parsimonious tree, Pseudoseisuropsis was retrieved as a sister group of woodcreepers (Dendrocolaptinae) with low support. However, slightly suboptimal hypotheses, which could not be completely ruled out, suggest that this genus may be more closely related to other clades of Furnariidae. Hence, we agree with previous authors in regarding Pseudoseisuropsis as Furnariidae Incertae sedis. In addition, two fragmentary fossils ascribed to Pseudoseisuropsis were included in taxonomic comparisons: P. cuelloi, in order to assess the possibility that P. wintu sp. nov. belongs to that species, and another paratype of P. nehuen, to reassess its taxonomic identity.

Mesozoic avian eggs are rare, especially from the mid-Cretaceous basins of Zhejiang Province, China. Here we report an avian egg from the Lower Cretaceous (Albian) Liangtoutang Formation. The specimen (JYM F0033) measures 50 mm × 32 mm and the 166-µm-thick eggshell consists of three structural layers of calcite. The mammillary layer (ML) and overlying continuous layer (CL) each measure approximately 46 µm, whereas the outermost, external layer (EL) measures 74 µm. Ratios of these layers are ML:CL:EL = 1:1:1.6. An external layer that exceeds the thickness of the continuous layer represents an autapomorphy of this new egg type, which we herein establish as Pachycorioolithus jinyunensis oogen. et oosp. nov. within Pachycorioolithidae oofam. nov. Documentation of eggshell features and their first occurrence in the fossil record provides phylogenetically important information that may potentially aid in clarifying the evolution of avian reproduction and biology.

The early Frasnian turiniid thelodont Neoturinia hutkensis gen. nov. is re-described on the basis of a new large scale set from the Chahriseh section in central Iran. Detailed morphological and histological information supports a new generic affinity for this species, which was previously assigned to Turinia. The generic affinity of other turiniid thelodonts from Gondwana is tested by a phylogenetic analysis based on scales, which proposes that most taxa from Gondwana form a clade separate from that comprising the first-studied Laurussian forms, including the type species Turinia pagei Powrie, 1870. This suggests that many of the Turinia species from Gondwana should be separated from this genus and need to be revisited. On the strength of the analysis, younger Gondwanan taxa in the mid-early Late Devonian should probably be referred to the new genus; one Late Silurian taxon from eastern Gondwana is removed. A biogeographic analysis, using a parsimony ancestral state method, is also conducted in order to discuss dispersal patterns in relation to the achieved model of interrelationships.

Freshwater fish fossils representing two or more species of Sander (S. lucioperca, S. svetovidovi, and Sander sp.) and Leobergia zaissanica are reported from a number of localities in Southeastern Europe. These localities sample the late Miocene through early Pliocene, when the landscape was undergoing major changes associated with the collision of the Afro-Arabian and Eurasian plate. This caused changes to ocean circulation with the closing of the Tethys, as well as uplift of mountain ranges in Europe. This was also a period of significant climate change, with the onset of polar glaciation causing a cooling, drying phase globally but also specifically documented for this region. The fossil fish material documents the presence of percids during this time and also the apparent loss of Leobergia in the Pliocene. The loss of Leobergia may well have been caused by a lower tolerance to cool climates of this genus compared to Sander, a genus with five extant species.

Orthogonikleithrus francogalliensis sp. nov., a new species of the family Orthogonikleithridae from the Late Jurassic Plattenkalks of Cerin (Ain, France), is described. The specimens were collected during excavations in Cerin by the Université Claude Bernard, Lyon. The fish were not immediately identified as new taxa but only in the framework of a current study on the temporal and spatial distribution of orthogonikleithrid fishes. The new species is superficially similar to Orthogonikleithrus hoelli but differs in several anatomical features, such as the presence of teeth, the number of tubules in the cephalic lateral line system, and the number of hypurals and uroneurals. Furthermore, due to the record of the genus Orthogonikleithrus in Cerin, the spatial distribution of this genus is extended, because it formerly was only known from Zandt and Ettling (both Bavaria, Germany).

We describe new material of Rhinocerotidae recently collected in western Kenya. A skull from Karungu is one of the best-preserved Miocene skulls in Africa. It differs substantially from that of Rusingaceros leakeyi, the only other relatively well-known rhino from this region and age, in its degree of brachycephaly, possession of a deep nasal notch, and long nasal bones that probably carried a horn of moderate size. Miocene African rhinos are still too poorly known to resolve their phylogenetic relationships, but we tentatively assign this skull to a new species of Victoriaceros, a genus whose type species comes from the younger site of Maboko, although the Karungu skull has a much smaller nasal horn. A parsimony analysis resolves them as sister species within the Elasmotheriini, close to the other African genera Turkanatherium and Chilotheridium, but we consider this result debatable, as Victoriaceros differs considerably from them. Still, they might all be descended from European forms. A partial skull from Gumba is assigned to the Aceratheriini, making it one of the earliest representatives of this group and suggesting that the origin of this tribe could be African.

We describe isolated shark teeth collected in levels of the Calafate Formation (Maastrichtian, Late Cretaceous) on the southeast coast of Argentino Lake, Calafate City, Santa Cruz Province, Argentina. The teeth belong to the hexanchiform Notidanodon dentatus, a new species of the squaliform Protosqualus, and an indeterminate species of the echinorhiniform genus Echinorhinus. The record of Notidanodon constitutes the first in South America. The report of Notidanodon associated with plesiosaur remains is in accordance with previous records from around the world. Protosqualus argentinensis, nov. sp., which is the first record of the genus in South America, is characterized by having teeth with a apicobasally tall root and serrated cutting edges, among other features. Echinorhinus sp. constitutes one of the oldest records of this genus on the continent and one of the few Mesozoic records worldwide. This shark association is clearly distinct from coeval selachian faunas from northern Patagonia, which exhibit clear Tethyan influences. Instead, it shows some similarities to other high-latitude selachian faunas, including Australia, New Zealand, and Antarctica. It is possible that the Cretaceous selachian assemblages of Patagonia may be separated into two different associations: northern Patagonian faunas are related to more temperate associations of lower paleolatitudes, whereas those of southern Patagonia are closer to other southern localities.

The La Guajira Peninsula, Colombia, has a continuous vertebrate fossil record that includes both the late early-early middle Miocene and the Pliocene. Crocodilians from the early to early middle Miocene Jimol and Castilletes formations include gavialoids, recovered from both coastal and shallow marine deposits, and caimanines representing early records of the specialized caimanine taxa Purussaurus and Mourasuchus. Crocodyloid specimens from the Pliocene Ware Formation are assigned to Crocodylus and represent one of the oldest occurrences of the genus in the New World. Records from the La Guajira Peninsula suggest that diverse crocodilian assemblages were already established by the late early Miocene, including several widely distributed lineages that persisted for several million years. Crocodylus is a recent immigrant to South America that occupied habitats left vacant by the extinction of several crocodilian lineages.

The ontogeny of early-diverging dinosauromorphs is poorly understood because few ontogenetic series from the same species-level taxon are known and what is available has not been extensively documented. The large numbers of skeletal elements of the silesaurid Asilisaurus kongwe recently recovered from Tanzania provide an opportunity to examine the ontogenetic trajectory of the earliest known member of Ornithodira and one of the closest relatives to Dinosauria. We examined the ontogeny of the femur and the histology of a series of long bone elements. We observed bone scar variation in a series of femora (n = 27) of different lengths (73.8–177.2 mm). We hypothesize that most femora follow a similar developmental trajectory; however, we observed sequence polymorphism in the order of appearance and shape of bone scars, and we quantified this polymorphism using ontogenetic sequence analysis (OSA). Additionally, five femora, three tibiae, a fibula, and a humerus were thin-sectioned to examine osteological tissues. No lines of arrested growth (LAGs) are present in any specimen, and there is little histological information about the ontogenetic stage of femora, although none have slowed or ceased growth. The woven-fibered bone present in the cortex of elements sectioned is similar to that of the earliest dinosaurs. This sequence polymorphism provides an alternate hypothesis for the robust/gracile dichotomy found in early dinosaurs often interpreted as sexual dimorphism. The shared femoral features found in Asilisaurus and early dinosaurs suggest that this ontogenetic pattern is plesiomorphic for Dinosauria, and that size is a poor predictor of maturity in early dinosauriforms.