The sauropodiform sauropodomorph dinosaur Melanorosaurus readi Haughton, 1924, from the lower Elliot Formation (Norian) of South Africa, has had a checkered taxonomic history. This is due to the lack of published information on the original syntype material and the use of referred specimens as the primary source of anatomical information on the taxon. Here, we present a revised osteology of Melanorosaurus based solely on the syntype series and argue that the latter includes the remains of a single, associated individual that we designate the lectotype. The species can be diagnosed on the basis of features of the caudal vertebrae and ilium but we restrict the hypodigm to the lectotype pending detailed reassessment of all referred specimens. Melanorosaurus has been used as an external specifier in the definition of Sauropoda, but given the fragmentary nature of the material, its lack of clear ‘sauropod-like’ features, and its phylogenetic lability we suggest that this is no longer appropriate.

The Siwalik Giraffidae fauna is diverse and includes species placed in Sivatheriinae, Giraffinae, and Giraffokeryx. We describe a new genus and species of giraffid, from the Middle Miocene of the Chinji Formation and Nagri Formation in Pakistan. Lyra sherkana gen. et sp. nov. et is unique among the Giraffidae due to the features of its cranial appendages. This taxon possesses a pair of ossicones that are positioned above and slightly medial to the orbits. The ossicones have a unique curvature resembling an ancient Greek harp or lyre, extending outwards and then curving forwards distally with a final backwards twist at the tip. The ossicones have a multi-layered surface. This new species also has large supraorbital sinuses, creating a large boss above the orbit. This last feature is only shared with the later and larger Bramatherium, which is the only giraffid known to also have an enlarged supraorbital boss. This suggests a possible relationship between these two taxa, both present in the Siwaliks, with Bramatherium appearing later than Lyra, during the Late Miocene. The presence of this new taxon increases the diversity not only of the Siwaliks fauna but of the Giraffidae family in general and helps shed light on the poorly known Middle Miocene giraffid faunas.

We present a new taxonomic study of fossil giraffids from the Siwaliks of Pakistan. The recovered material belongs to the family Giraffidae and includes a cranium of Vishnutherium priscillum, maxillary isolated cheek teeth of Bramatherium grande, maxillary isolated cheek teeth and mandibular fragments of Bramatherium megacephalum. These specimens were collected from the localities of Dhok Bun Ameer Khatoon, Chakwal district, and Hasnot, Jhelum district, Punjab, Pakistan. These outcrops belong to the Chinji Formation and Dhok Pathan Formation, respectively, of lower to middle Siwaliks, dated as Middle to Late Miocene in age. The presence of fossil fauna that primarily fed on herbaceous, grassy, and bushy vegetation suggests that both Dhok Bun Ameer Khatoon and Hasnot were dominated by mixed woodland habitats. These localities have a very rich fossil fauna and the cranium of Vishnutherium priscillum is the first that has been reported from Dhok Bun Ameer Khatoon.

Caviomorphs are the neotropical hystricognathous rodents (Ctenohystrica: Hystricognathi: Caviomorpha). Octodontoidea are today the richest and most speciose clade of caviomorphs. Their fossil record also reveals a wide array of extinct species, including Acarechimys, a taxon with a widespread South American distribution and extensive temporal range. This genus comprises at least five species documented in deposits ranging from the late Oligocene to the Middle Miocene. Here, we report the discovery of a new species of Acarechimys from Upper Miocene deposits of the Envira River (PRE06 outcrop), situated in the Acre State, western Brazilian Amazonia. The new species differs from the other species of the genus in having lower molars with a strong posterior arm of the metaconid, the presence of a mesostylid (usually prominent) and a neomesolophid forwardly directed and connected to the metalophulid I on m1 but not on m2–3, and the absence of posterior arm of the protoconid. This taxon represents the youngest known species of the Acarechimys lineage to date. Its occurrence in Western Amazonia strengthens support for the hypothesis that South American rodent lineages survived longer during the Neogene at low latitudes than in the southern regions of the continent.

Multiple cranial and mandibular remains of Hyperodapedon huxleyi known from the lower part of the Upper Triassic Maleri Formation were examined to reveal distinct bite marks. These were identified as punctures based on their circular or oval or elliptical outline and deep penetration into the cortical bone, and were found associated with several bone-damaging features such as radiating fractures, serrated boundaries, and collapsed bony surface. In addition, bite traces or drag marks in the form of parallel grooves with U-shaped cross sections are identified. The bite marks are compared with dental morphology of varied Late Triassic carnivores of India, and the probable producers are suggested to be phytosaurs and dinosauriforms. The Maleri trophic structure or food web is reconstructed to reveal interconnectedness between different animal groups, unconfined feeding habits of the animals where the predators were inclined towards opportunistic feeding rather than a niche-based dietary habit. The study highlights the significance of bite marks in the reconstruction of ancient paleoecosystems.

New thylacinid species of Badjcinus, Nimbacinus, and Ngamalacinus are described from upper Oligocene deposits of the Riversleigh World Heritage Area, northwestern Queensland. Badjcinus timfaulkneri, Nimbacinus peterbridgei, and Ngamalacinus nigelmarveni are among the oldest thylacinids yet known and indicate an earlier diversification of the family than previously understood. Maximum parsimony analysis supports a sister group relationship between Ng. nigelmarveni and Ng. timmulvaneyi, but the relationships of the two other new taxa are unresolved. Bayesian dated total evidence analysis using morphological and molecular data supports the generic assignment of B. timfaulkneri and Ng. nigelmarveni but not that of Ni. peterbridgei. Both phylogenies herein support a taxonomic reassignment of Thylacinus macknessi to the genus Wabulacinus, a conclusion also supported by the results of previous studies. Body mass estimates based on molar size regressions indicate body sizes ranging from 3.7 kg to 11.4 kg for the new thylacinid species. Badjcinus timfaulkneri exhibits an extremely deep jaw compared with other thylacinids, with mandibular bending strength analysis suggesting that it was a highly durophagous carnivore much like the modern dasyurid Sarcophilus harrisii. This analysis also suggests Ni. peterbridgei had a dentary more similar in shape to that of plesiomorphic thylacinid faunivores such as Ni. dicksoni and T. cynocephalus suggesting that it had a relatively more generalist faunivorous diet. The molars of Ng. nigelmarveni suggest they were better suited for longitudinal slicing than the molars of B. timfaulkneri and Ni. peterbridgei, indicating a more hypercarnivorous diet compared with that of those species.

Prozalambdalestes cratodus gen. et sp. nov. is based on a fragmentary dentary from the Lower Cretaceous (Aptian–Albian) Khovoor locality in Gobi Desert, Mongolia. This is the largest eutherian in the Khovoor mammal assemblage. It shows dental specializations of Zalambdalestidae such as procumbent, ever-growing gliriform first lower incisor with restricted enamel and reaching posteriorly p5, and mesiodistally compressed lower molar trigonids. The enamel is restricted to the ventrolabial and ventrolingual sides of the mesial half of the incisor and the enamel band is higher on the labial side. The new taxon retains five lower premolars, with p1 smaller than p2 and p3 smaller than adjacent premolars, and the Meckelian groove. It also differs from other zalambdalestids by position of mental foramina (under p3 and p5), p1–3 obliquely set in dentary, and lower molar talonids wider than trigonids. Phylogenetic analysis places Prozalambdalestes gen. nov. in a polytomy with Albian Zhangolestes, Turonian Kulbeckia, and the clade of Campanian zalambdalestids from Mongolia and Kazakhstan. CT data in Zalambdalestes and comparison with Prozalambdalestes gen. nov. show that the four lower premolars in Zalambdalestes are p2, p3 (variable present), p4, and p5. Consequently, the three lower premolars of Barunlestes and Zofialestes are p2, p4, and p5. The other diagnostic characters of Zalambdalestidae are reviewed.

Pterosaurs were the earliest and largest vertebrates to evolve powered flight, but they are the only major volant group that has gone extinct. Attempts to understand pterosaur flight mechanics have relied on aerodynamic principles and analogy with extant birds and bats. Both lines of inquiry rely on the size, three-dimensional shape, and internal structure of flight bones, which in pterosaurs are surprisingly rare. Remarkably, two new large-bodied pterosaur individuals with three-dimensionally preserved wing elements were recently recovered from Upper Cretaceous (Maastrichtian) horizons of Jordan. Both specimens represent azhdarchoid pterosaurs; one is referrable to the giant species Arambourgiania philadelphiae (ca. 10 m wingspan) and the second to a new, smaller species Inabtanin alarabia gen. et sp. nov. (ca. 5 m wingspan). In this study, we describe these new specimens and use high-resolution micro-computed tomography scans to reconstruct and compare the internal osteology of the humeri of these two differently sized species to that of extant birds, for which internal bone structure can be correlated with flight behavior. The humerus of Arambourgiania exhibits a series of helical ridges formed along the cortical bone, whereas Inabtanin exhibits a denser pattern of hollow struts. Variation in internal structure for these individuals likely reflects responses to mechanical forces applied on the wings of pterosaurs. Results indicate that Inabtanin has internal bone morphology similar to that of flapping birds, whereas the internal morphology of Arambourgiania is most similar to that of soaring birds.

The Lower to Middle Jurassic Kota Formation of India has yielded abundant yet disarticulated skeletal remains attributed to the basally diverging sauropod Kotasaurus yamanpalliensis. The hypodigm of Kotasaurus yamanpalliensis includes four ellipsoidal elements that we identify as tail clubs, based on morphological similarities to tail clubs attributed to two basal sauropods from China: Shunosaurus lii, for which a fully articulated tail series was recovered, and Omeisaurus tianfuensis. Detailed comparison of the Chinese and Indian tail clubs suggests that they are composed of up to three individual elements that fuse in adulthood. Computed tomography of the Indian tail clubs reveals their internal structure, which shows incremental growth lines as well as other features whose origin and function remain unknown. The Indian and Chinese tail clubs share a similar temporal range (Early to Middle Jurassic) and similar morphologies, which raises the question of whether sauropod tail clubs evolved once, multiple times, or were gained and then lost within basally diverging members of Sauropoda. We describe four new characters to reflect the morphological constituents of sauropod tail clubs known to date.

An almost complete dinosaur femur found in the Baynshire Formation (late Cenomanian to Santonian; Mongolia) in 1963 during the Polish–Mongolian Paleontological Expeditions is described here for the first time. The morphology of the femur and bone histology suggest that the specimen was a representative of the Titanosauriformes, the predominant sauropod clade during the Cretaceous. Bone tissue exclusive to this clade, modified laminar bone that indicates a reduced growth rate, is identified in the thin sections taken from the femur. Based on its bone histology, the already ca. 20-meter-long specimen appears to be a subadult. This specimen achieved a significantly larger size compared with other Titanosauriformes with modified lamellar bone at a similar growth stage.

Edentulism—lack of teeth—is a derived condition among salientians (total-group frogs and toads) that has arisen independently at least 22 times within the crown group, Anura. Despite this frequency, edentulism (in part or complete) is seldom documented in the salientian fossil record, and thus its evolutionary history remains obscure. A ∼90 Ma gap presently exists between the edentulous salientians Notobatrachus reigi (late Toarcian; Argentina) and the five known species from the latest Cretaceous of Argentina, South Africa, Canada, and the U.S.A. Here we report a new instance of edentulism in an Early Cretaceous salientian, Ostrombatrachos nodos gen. et sp. nov., based on a maxilla from an early Albian age (∼ 111 Ma) locality in the Cloverly Formation of Wyoming, U.S.A. Although incomplete, the holotype maxilla exhibits a distinctive suite of features (i.e., edentulous; pit-and-ridge external ornament; shallow groove across anteriormost portion of margo orbitalis and continuing anteroventrally down lateral surface of pars facialis to interrupt the external ornament; medially expanded orbital flange; moderately broad, deep lamina horizontalis; and weakly developed processus pterygoideus) that is unknown in any other salientian. This new taxon represents the oldest occurrence of edentulous maxillae in a Laurasian salientian and helps fill the long temporal gap in edentulism among salientians. O. nodos gen. et sp. nov. does not appear to be closely related to other edentulous Mesozoic salientians, suggesting it represents yet another independent evolution of this feature.

The passerines or songbirds (Passeriformes) of the Early Miocene St. Bathans Fauna (Otago, New Zealand) have received little attention since studies of this lacustrine fauna began, with just one species, Kuiornis indicator (Acanthisittidae), formally described. In this preliminary study, we assess the species diversity of passerines in the fauna based primarily on size and features of the tarsometatarsus, one of the most commonly preserved elements. Our results demonstrate the presence of between 10 and 17 passerine species in the fauna. These included a meliphagid (honeyeaters), larger than the extant Tui Prosthemadera novaeseelandiae, and newly discovered specimens that further support the previously reported presence of a large cracticid, the size of the Australian Magpie Gymnorhina tibicen. Despite the presence of seven acanthisittids in Holocene faunas and studies that hypothesize that at least four acanthisittid genera were present in the Miocene, we only found evidence for K. indicator, possibly due to a collecting bias. Excluding acanthisittids, the passerine diversity in the St. Bathans Fauna was similar to that of the entire South Island prior to human arrival, all of which suggests that Zealandia had a greater diversity of songbirds during the Early Miocene than in the Holocene, with numbers declining possibly as a result of subsequent losses in floral diversity.

Rich bone beds from the lower Eocene strata of the Golden Valley Formation of Stark County, North Dakota reveal a speciose sympatric crocodylian fauna. However, analyses demonstrate limited phylogenetic diversity among these co-occurring taxa, and of the four species known for the locality, three are alligatorids and one is a crocodyloid. Phylogenetic hypotheses recover Chrysochampsa mylnarskii as a late lived member of Brachychampsini—a stem-based clade including Brachychampsa montana and all alligatorids more closely related to it than to Caiman crocodilus or Alligator mississippiensis—and a new genus and species, Ahdeskatanka russlanddeutsche groups with species of Allognathosuchus. The crocodylians, partitioned by body size and plan, would have occupied an array of ecological niches and feeding strategies. Whereas the large-bodied alligatorid Chrysochampsa mylnarskii preserves a generalist morphology, Ahdeskatanka russlanddeutsche bears a short, broad snout and globular distal teeth. Contemporaneous with a peak in alligatoroid diversity during this interval, Ahdeskatanka russlanddeutsche is an exemplar of a radiation of small-bodied alligatorids with crushing dentition and preserves the ancestral alligatorid feeding strategy. Trophic dynamics of the locality diverge from modern environments and the abundant crocodylians may have filled the ecological niche of large mammalian carnivores conspicuously absent here. This alligatorid-rich crocodylian fauna evolved in swampy lowlands and meandering streams flanked by subtropical forests during one of the hottest sustained intervals in Earth history. The lush, highly productive ecosystems preserved in the Golden Valley Formation inform the evolutionary history of North American alligatorids and preserve significant biodiversity following the Paleocene–Eocene Thermal Maximum.

Parutaetus is an early-diverging Euphractinae cingulate that inhabited South America during the middle Eocene–early Oligocene. Four species are known: P. chicoensis, P. clusus, P. chilensis, and P. punaensis. Here, we describe a new species of this genus from Guabirotuba Formation (middle-upper Eocene of Brazil). The osteoderms differ from other species of the genus by presenting: (i) more surface glandular and piliferous foramina; (ii) the articulation surface of the area between the osteoderms is flat and full of pronounced, round, and anastomosed projections forming serrated external and medial edges with a median projection (indentations); and (iii) larger size than other species of the genus. In combination, this suite of traits is not present in other species of the genus. The increase in the number of surface glandular and piliferous foramina may be associated with the global cooling that occurred during the middle–late Eocene that affected the South American fauna. Finally, the new species expands the knowledge about the diversity of taxa that inhabited southeast South America during the Paleogene.