A new crocodylian, Dongnanosuchus hsui n. gen. n. sp., is described mainly based on four well-preserved skulls from the Eocene Youganwo Formation of the Maoming Basin, southeastern China. It is an alligatoroid and phylogenetically nested within the Orientalosuchina. Dongnanosuchus hsui n. gen. n. sp. differs from all other orientalosuchines primarily in certain features of the skull: (1) a preorbital ridge connects posteriorly with the dorsal orbital rim and a ridge around the anteroventral margin of the orbit, (2) the palatine is short and does not reach the posterior border of the suborbital fenestra, (3) the external mandibular fenestra is closed, and (4) the splenial joins the formation of the mandibular symphysis. The discovery of Dongnanosuchus hsui n. gen. n. sp. confirms the monophyly and North American origin of the Orientalosuchina but suggests that the clade dispersed to Asia via Beringia after diverging from the mainline rather than a sub-lineage of the Alligatoroidea in the Late Cretaceous.

UUID: http://zoobank.org/f8ca22f1-6323-462e-bf32-03c6a164c82e.

A partial skeleton of a short-necked plesiosaur excavated from the Upper Cenomanian of the Middle Yezo Group of Hokkaido, Japan, includes disarticulated vertebrae, the right half of the pectoral girdle, fragments of the pelvic girdle, ribs, gastralia, and gastroliths. Gastroliths are unusual in short-necked plesiosaurs. Skeletal characters indicate that the specimen belongs to the Family Polycotylidae, well known from North America, the former Soviet Republics, and possibly from New Zealand. They are rare in East Asia and hitherto unknown from Japan. Extensive ossification indicates that this specimen is an adult individual, yet it is smaller than the adult specimens of other known polycotylids. The elongated epipodial bones are a unique character of the specimen but are probably plesiomorphic. The fossil is evidence of biogeographical diversification of the family at the beginning of the Late Cretaceous.

A new species of polycotylid, Dolichorhynchops herschelensis, is described based on a well-preserved skeleton from the Upper Cretaceous (Campanian–Maastrichtian) Bearpaw Formation of Herschel, Saskatchewan. Its small size as an adult, the sharp rise in front of the parietal crest, and the straight ilium with narrow dorsal end are diagnostic features of this taxon. This is the first polycotylid plesiosaur described from the Bearpaw Formation, deposited during the critical period when polycotylids were disappearing from the Western Interior of North America.

Diandongosaurus acutidentatus Shang, Wu & Li, 2011 is restudied on the basis of a new specimen. The new specimen provides further information on the palate of the skull, the shoulder girdle, the gastralia and hind limbs, and permits revision of the diagnosis. Newly added or modified diagnostic characters include the presence of a few small vomerine teeth, the presence of an ectopterygoid, lateral elements of gastralia distally swollen and curving dorsally, boomerang-shaped interclavicle and clavicle with a distinct anterolateral process. Slight variations in the vertebral counts, girdle morphology, and phalangeal formulae are attributed to the intraspecific variations. A revised phylogenetic analysis demonstrates that Diandongosaurus is closely related to the Nothosauroidea and that certain Chinese taxa (e.g. Keichousaurus) previously affiliated with the Pachypleurosauridae are more closely related to the Nothosauroidea. The effect of inclusion or exclusion of fragmentary taxa in the phylogenetic analysis is observed in the branching pattern of the cladogram, but it has little effect on the morphological characterization of the major clades.