''Parahupehsuchus'' is an extinct

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of hupehsuchian

marine reptile Marine reptiles are reptiles which have become secondarily adapted for an aquatic or semiaquatic life in a marine environment. Only about 100 of the 12,000 extant reptile species and subspecies are classed as marine reptiles, including mari ...

s 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 251.9 Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which ...

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 "unisp ...

, 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 (: 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 these reptil ...

neural spine Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal ...

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 wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to ancho ...

, 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 (geology), age in the Early Triassic epoch (geology), epoch; in chronostratigraphy, it is a stage (stratigraphy), stage in the Lower Triassic series (stratigraphy), series. It spans the time betw ...

)

Jialingjiang Formation The Jialingjiang Formation (嘉陵江组) is a geologic feature associated with the Sichuan Basin of China, generally underlying the area of the basin, with its origins dating to the Early Triassic period of geologic time, around a quarter of a b ...

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 Temnospondyli (from Gre ...

Hubei Province Hubei is a province in Central China. It has the seventh-largest economy among Chinese provinces, the second-largest within Central China, and the third-largest among inland provinces. Its provincial capital at Wuhan serves as a major politi ...

, 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 vertebra In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebrae of intermediate size between the cervical and lumbar ve ...

e, 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

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