Eohupehsuchus

Eohupehsuchus is a genus of extinct aquatic diapsid from the Upper Spathian (latest Early Triassic) of Hubei Province, located in Central China. The genus is monotypic and belongs to the order Hupehsuchia, whose members are characterized by toothless beak-like snouts, a row of dermal plates along their backs, and aquatic adaptations including paddle-shaped limbs and fusiform bodies with pachyostotic ribs.

Eohupehsuchus is known only from its holotype, WGSC (Wuhan Centre of Geological Survey, China) V26003. It is the smallest known hupehsuchian along with Nanchangosaurus, measuring about 40 cm (16 in) long. Phylogenetic analyses have repeatedly recovered it as the second-most basal member of the Hupehsuchia and as the sister group to the family Hupehsuchidae. A pathology on the left forelimb of the holotype was interpreted by its discoverers as a bite wound from a larger marine reptile, and used to argue an early onset for modern trophic structures in marine ecosystems following the Permian-Triassic mass extinction (see Paleoenvironment and paleoecology).

The generic name Eohupehsuchus comes from the Greek "eos" (Greek: ἠώς), meaning "early" or "dawn;" "Hupeh," an anglicisation of Hubei (Chinese: 湖北; pinyin: Húběi); and the Greek "Soûchos" (Greek: Σοũχος), meaning "Sobek." (The Greek name for Sobek is a common element of scientific names for animals that resemble crocodiles, and is often translated as "crocodile" in this context, but hupehsuchians are not close relatives of crocodilians, the order that includes modern crocodiles.) The specific name brevicollis comes from the Latin "brevis," meaning "short," and "collum," meaning "neck." Thus the generic name can be translated as "early Hubei crocodile," and the full binomial name as "short-necked early Hubei crocodile."

Discovery and history

WGSC V26003 was discovered in Yangping, a town in Yuan'an County in Hubei Province, Central China, and excavated by Chinese paleontologists Xiao-hong Chen and Long Cheng in 2011. Despite being exposed at the surface when discovered, the specimen is largely articulated and moderately complete, preserving much of the head, trunk, left pectoral girdle, and left forelimb, and parts of the left hindlimb and the anterior part of the tail. However, several of the preserved elements have been extensively damaged by erosion, including the left pelvic girdle, and other elements were completely destroyed by erosion before discovery, including the tips of the jaws.

The genus was named and formally diagnosed in a 2014 paper published in the open access journal PLOS One by paleontologists Xiao-hong Chen, Ryosuke Motani, Long Cheng, Da-yong Jiang, and Olivier Rieppel.