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Parioxys ferricolus Cope, 1878 is a long-neglected taxon of dissorophid temnospondyls from the early Permian (Cisuralian) of Texas. Reexamination of the original material and preparation of a previously undescribed specimen shed some light on the ontogeny and reveal numerous eucacopine features. P. ferricolus is characterized by: (1) a preorbital region 1.5 times as long as the posterior skull table in juveniles and twice as long in adults, (2) a parietal only two-thirds the length of the frontal, (3) interpterygoid vacuities shorter than half the skull length, (4) choanae posteriorly extended, and (5) vomer with enlarged, V-shaped median depression. P. ferricolus is found nested with Kamacops acervalis Gubin, 1980, with which it shares synapomorphies in the palate, within the dissorophid clade Eucacopinae. [ABSTRACT FROM AUTHOR]

A fragment of a right dentary with one postcanine tooth from the Upper Triassic (Rhaetian) Scots Bay Member of the McCoy Brook Formation at Wasson Bluff, Nova Scotia, Canada, represents the first record of the tritylodontid cynodont Oligokyphus from the early Mesozoic of eastern North America. In addition, three dissociated postcranial bones from the same horizon and locality are referable to derived cynodont therapsids. One of these elements, a nearly complete right humerus, can be assigned to Tritylodontidae. Two other bones, an ulna and incomplete ischium, belong to indeterminate derived cynodonts but show no features allowing more precise taxonomic identification. The presence of Oligokyphus in the McCoy Brook Formation provides additional evidence for the remarkably wide geographic distribution of many latest Triassic and Early Jurassic continental tetrapods. [ABSTRACT FROM AUTHOR]

The group of Permo-Carboniferous tetrapods known as Recumbirostra have recently been hypothesized to represent the earliest radiation of fossorial reptiles. Therefore, understanding the anatomy and diversity of this clade is essential to understanding the origin and early evolution of amniotes. Here, we redescribe the diminutive 'microsaur' Odonterpeton triangulare from the Moscovian-age deposit of Linton, Ohio, revealing new details on the structure of the cranium and palate, including the presence of a conspicuous transverse flange of the pterygoid, which is a feature traditionally associated with early amniotes. Phylogenetic analysis supports the placement of Odonterpeton triangulare within Recumbirostra as sister taxon to the recently described Joermungandr bolti from the slightly older Mazon Creek, Illinois, Lagerstätte. Together, these two diminutive recumbirostrans are placed in an Odonterpetidae clade. Furthermore, we provide a discussion of newly recognized anatomical features in recumbirostrans and discuss major features of recumbirostran phylogeny. We designate a new recumbirostran clade, Chthonosauria (Brachystelechidae + Molgophidae), which is supported by a number of shared derived cranial features. [ABSTRACT FROM AUTHOR]

The holotype of cf. Halticosaurus orbitoangulatus Huene, 1932, comprises an incomplete and macerated but associated skull of an archosaurian reptile from the middle (second) Stubensandstein (middle Löwenstein Formation; Upper Triassic: Norian) of Baden-Württemberg, Germany. It was originally interpreted as a theropod dinosaur but more recently it has been suggested that this taxon has crocodylomorph affinities. Detailed preparation of the holotype of cf. H. orbitoangulatus has revealed much new anatomical information and permitted reassessment of its affinities. The maxilla lacks both a distinct antorbital fossa and a medial bony lamina bordering the antorbital fenestra. The lateral surface of the dentary bears a pronounced horizontal ridge. The squamosal differs from that of basal crocodylomorphs in being L-shaped rather than arcuate in dorsal view, lacking a dorsolateral overhang, and lacking an interlocking contact with the paroccipital process as, for example, in the basal crocodylomorph Saltoposuchus connectens from the same horizon and locality. Phylogenetic analysis placed cf. H. orbitoangulatus amongst loricatan pseudosuchians (but not amongst Crocodylomorpha) rather than amongst theropod dinosaurs. The holotype of cf. H. orbitoangulatus represents a previously unrecognized taxon of loricatan pseudosuchian, which is here named Apatosuchus orbitoangulatus and set apart from other known Norian-age non-crocodylomorph loricatans by its apparently much smaller size. © 2013 The Linnean Society of London [ABSTRACT FROM AUTHOR]

This paper presents a detailed description of the skull and part of the mandible of the crocodyliform reptile Hamadasuchus rebouli from the Kem Kem beds (Upper Cretaceous: Albian–Cenomanian) of south-eastern Morocco. This taxon of deep-snouted ziphodont crocodyliform can be diagnosed by a number of autapomorphies. Phylogenetic analysis of a diverse array of crocodylomorph taxa found strong support for a clade comprising H. rebouli, Peirosauridae, and Sebecus. The name Sebecia nom. nov. is proposed for this grouping, which is diagnosed by numerous characters, including the participation of the quadratojugal in the mandibular condyle. The distribution of this diverse and long-lived clade lends further support to the biogeographical hypothesis that faunal connections existed between Africa and South America well into mid-Cretaceous times. © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society, 2007, 149, 533–567. [ABSTRACT FROM AUTHOR]

Present‐day crocodylians exhibit a remarkably akinetic skull with a highly modified braincase. We present a comprehensive description of the neurocranial osteology of extant crocodylians, with notes on the development of individual skeletal elements and a discussion of the terminology used for this project. The quadrate is rigidly fixed by multiple contacts with most braincase elements. The parabasisphenoid is sutured to the pterygoids (palate) and the quadrate (suspensorium); as a result, the basipterygoid joint is completely immobilized. The prootic is reduced and externally concealed by the quadrate. It has a verticalized buttress that participates in the canal for the temporal vasculature. The ventrolateral processes of the otoccipitals completely cover the posteroventral region of the braincase, enclose the occipital nerves and blood vessels in narrow bony canals and also provide additional sutural contacts between the braincase elements and further consolidate the posterior portion of the crocodylian skull. The otic capsule of crocodylians has a characteristic cochlear prominence that corresponds to the lateral route of the perilymphatic sac. Complex internal structures of the otoccipital (extracapsular buttress) additionally arrange the neurovascular structures of the periotic space of the cranium. Most of the braincase elements of crocodylians are excavated by the paratympanic pneumatic sinuses. The braincase in various extant crocodylians has an overall similar structure with some consistent variation between taxa. Several newly observed features of the braincase are present in Gavialis gangeticus and extant members of Crocodylidae to the exclusion of alligatorids: the reduced exposure of the prootic buttress on the floor of the temporal canal, the sagittal nuchal crest of the supraoccipital projecting posteriorly beyond the postoccipital processes and the reduced paratympanic pneumaticity. The most distinctive features of the crocodylian braincase (fixed quadrate and basipterygoid joint, consolidated occiput) evolved relatively rapidly at the base of Crocodylomorpha and accompanied the initial diversification of this clade during the Late Triassic and Early Jurassic. We hypothesize that profound rearrangements in the individual development of the braincases of basal crocodylomorphs underlie these rapid evolutionary modifications. These rearrangements are likely reflected in the embryonic development of extant crocodylians and include the involvement of neomorphic dermal anlagen in different portions of the developing chondrocranium, the extensive ossification of the palatoquadrate cartilage as a single expanded quadrate and the anteromedial inclination of the quadrate. [ABSTRACT FROM AUTHOR]

A recent survey of the middle Cenomanian Dunvegan Formation along the Peace River, Alberta, has yielded a partial skull of a large acipenseriform fish. The fossil was from an animal approximately 5 m in length, based on comparisons with living relatives. Though incomplete, this represents an important record of mid-Cretaceous fish from northern North America, as formations of this age are virtually unexplored in northern regions. This fossil is the oldest acipenserid from North America, and one of the most northerly known. [ABSTRACT FROM AUTHOR]