''Pantosaurus'' ("all lizard") is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

plesiosaur The Plesiosauria (; Greek: πλησίος, ''plesios'', meaning "near to" and ''sauros'', meaning "lizard") or plesiosaurs are an order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared ...

from the

Late Jurassic The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the name ...

( Oxfordian) of what is now

Wyoming Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the south ...

. It lived in what used to be the

Sundance Sea The Sundance Sea was an epeiric sea that existed in North America during the mid-to-late Jurassic Period of the Mesozoic Era. It was an arm of what is now the Arctic Ocean, and extended through what is now western Canada into the central western ...

. It was originally named ''

Parasaurus ''Parasaurus'' (meaning "near lizard") is a genus of pareiasaur known from fossils collected in the Kupferschiefer in Germany (Hesse, Thuringia and Lower Saxony), dating to the Late Permian (Wuchiapingian). The type species, ''Parasaurus geinit ...

'' ("near lizard") by

Othniel Charles Marsh Othniel Charles Marsh (October 29, 1831 – March 18, 1899) was an American professor of Paleontology in Yale College and President of the National Academy of Sciences. He was one of the preeminent scientists in the field of paleontology. Among h ...

in reference to ''

Plesiosaurus ''Plesiosaurus'' (Greek: ' ('), near to + ' ('), lizard) is a genus of extinct, large marine sauropterygian reptile that lived during the Early Jurassic. It is known by nearly complete skeletons from the Lias Group, Lias of England. It is disting ...

'', but that name was preoccupied, and Marsh changed it. The species ''Muraenosaurus reedii'' is in fact a

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...

of ''Pantosaurus''. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

YPM 543 is a partial articulated

skeleton A skeleton is the structural frame that supports the body of an animal. There are several types of skeletons, including the exoskeleton, which is the stable outer shell of an organism, the endoskeleton, which forms the support structure inside ...

, partially prepared to yield a distal

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

, four articulated

carpal The carpal bones are the eight small bones that make up the wrist (or carpus) that connects the hand to the forearm. The term "carpus" is derived from the Latin carpus and the Greek καρπός (karpós), meaning "wrist". In human anatomy, th ...

s, a fragment of the coracoid, and several isolated cervical

vertebra 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 ...

e from the Upper Member of the Sundance Formation. Other material includes USNM 536963, USNM 536965, UW 3, UW 5544 and UW 15938.

Palaeobiology

''Pantosaurus'' possesses between 35 and 40 cervical vertebrae, which are very similar in proportion and morphology to those of '' Muraenosaurus leedsii'' from the Oxford Clay Formation (

Callovian In the geologic timescale, the Callovian is an age and stage in the Middle Jurassic, lasting between 166.1 ± 4.0 Ma (million years ago) and 163.5 ± 4.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the ...

Middle Jurassic The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations co ...

) of

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

. The forelimb of ''Pantosaurus'' however can be differentiated from that of ''Muraenosaurus'', such as the relatively large size of the radius and the corresponding humerus-radius articulation. No ''Pantosaurus'' cranial material has yet been discovered.

Feeding

The discovery of an partially digested embryonic ichthyosaur (probably ''

Baptanodon ''Baptanodon'' is an ichthyosaur of the Late Jurassic period (160-156 million years ago), named for its supposed lack of teeth (although teeth of this genus have since been discovered). It had a graceful long dolphin-shaped body, and its jaws we ...

'') inside of a fossil referable to ''Pantosaurus striatus'' was the first evidence of the consumption of ichthyosaurs by plesiosaurs.

References

{{Taxonbar, from=Q7131914 Cryptoclidids Sauropterygian genera Late Jurassic plesiosaurs Late Jurassic reptiles of North America Jurassic plesiosaurs of North America Fossil taxa described in 1893 Taxa named by Othniel Charles Marsh

Palaeobiology

Feeding

See also

References