''Parahupehsuchus'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

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 na ...

n marine reptiles from the

Early Triassic The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which is a un ...

of China. The genus is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

, known from the single species ''Parahupehsuchus longus'' and based on a single specimen. Like other hupehsuchians, it had an elongated torso, a tail nearly as long as the rest of the body, short and paddle-like limbs, extra bones in the fore- and hind limbs, thick ribs and

gastralia Gastralia (singular gastralium) are dermal bones found in the ventral body wall of modern crocodilians and tuatara, and many prehistoric tetrapods. They are found between the sternum and pelvis, and do not articulate with the vertebrae. In thes ...

neural spine The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...

s of the vertebrae split into two parts, and bony plates over the neural spines. It differs from other hupehsuchians in having an even more elongated body and wider ribs that touch along their edges and have no spaces between them. The ribs connect with gastralia on the underside of the torso to form a bony "tube" around the body wall.

Description

''Parahupehsuchus longus'' is known from a single

type specimen In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes th ...

, WGSC 26005, measuring in length. It was found in 2011 from an outcrop of the Early Triassic (

Olenekian In the geologic timescale, the Olenekian is an age in the Early Triassic epoch; in chronostratigraphy, it is a stage in the Lower Triassic series. It spans the time between Ma and Ma (million years ago). The Olenekian is sometimes divided i ...

) Jialingjiang Formation in

Yuan'an County Yuan'an County () is a county in the west of Hubei province, People's Republic of China. It is under the administration of the prefecture-level city of Yichang. '' Yuanansuchus'', an extinct mastodonsauroid temnospondyl, is named after Yuan'a ...

Hubei Province Hubei (; ; alternately Hupeh) is a landlocked province of the People's Republic of China, and is part of the Central China region. The name of the province means "north of the lake", referring to its position north of Dongting Lake. The prov ...

, China. WGSC 26005 consists of a mostly complete left half of a skeleton lacking the skull and most of the tail. The torso of ''Parahupehsuchus'' is very elongated; it has 38 dorsal vertebrae, 10 more than in '' Hupehsuchus'' and the unnamed hupehsuchian IVPP V4070. The rib cage of ''Parahupehsuchus'' is narrow and tube-shaped, unlike the barrel-shaped rib cage of ''Hupehsuchus''. The ribs of ''Parahupehsuchus'' are unlike those of any other hupehsuchian. They are wide and flat, touching edge-to-edge to form a bony tube across the torso. Rows of gastralia on the underside of the torso form a bottom wall enclosing this tube. Each rib articulates with two dorsal vertebrae, wedged between the diapophysis and parapophysis of the vertebra in front of it and an anterior rib facet extending from the parapophysis of the vertebra behind it. Each rib sweeps backward from its connection with the vertebrae. The gastralia, which overlap the bottom ends of the ribs, sweep forward.

Phylogeny

References

Triassic ichthyosauromorphs Triassic animals of Asia Fossil taxa described in 2014 Paleontology in Hubei Ichthyosauromorph genera {{paleo-reptile-stub