Hupehsuchia

Hupehsuchia is an order of diapsid reptiles closely related to ichthyosaurs. The group was short-lasting, with a temporal range restricted to the late Olenekian age, spanning only a few million years of the Early Triassic. The order gets its name from Hubei Province, China, from which many specimens have been found. They are probable members of the clade Ichthyosauromorpha.

==Description== Hupehsuchians display an unusual combination of characteristics. The overall shape of the body is fusiform, with a long tail and large, paddle-like limbs. The skull is elongated and the jaws are edentulous. The rostrum is flattened with the premaxilla thought to form most of the dorsal and lateral surface, while the maxilla is mostly restricted to the ventral surface beyond the base of the rostrum. An opening between the nasal and the prefrontal bones in one hupehsuchian specimen (known as IVPP V3232) was initially interpreted as an antorbital fenestra, but is now thought to be an artifact caused by the damage of the surrounding bones during preservation. Its position is not indicative of a narial opening, either. More likely, the naris lies between the nasal and the maxilla in an area anterior to that of the supposed antorbital fenestra, although the preservation of this area in known specimens is too poor to prove definitively that it is the external naris and not an artifact of preservation, as is the case for the fenestra.