Pistosaurus
Pistosaurus (pistos in Greek meaning 'credible' and sauros 'lizard') is an extinct genus of aquatic sauropterygian reptile closely related to plesiosaurs. Fossils have been found in France and Germany, and date to the Middle Triassic. It contains a single species, Pistosaurus longaevus. Pistosaurus is known as the oldest "subaquatic flying" reptile on earth.
| Pistosaurus Temporal range: Middle Triassic, | |
|---|---|
| Fossil | |
| Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Superorder: | †Sauropterygia |
| Family: | †Pistosauridae Zittel, 1887 |
| Genus: | †Pistosaurus Meyer, 1839 |
| Type species | |
| †Pistosaurus longaevus Meyer, 1839 | |
The skull of Pistosaurus generally resembles that of other Triassic sauropterygians. However, there are several synapomorphies that make Pistosaurus distinguished: the long, slender, snout; the possession of splint-like nasals that are excluded from the external naris; and the posterior extension of the premaxilla to the frontals. Based on synapomorphies such as the small nasals size and the presence of interpterygoid vacuity, Pistosaurus is more closely related to Plesiosauria than to Nothosaurus.
Pistosaurus is often mistaken with Nothosaurus and Plesiosauria. Nothosaurus belongs to the clade Nothosauroidea from the middle Triassic (approximately 199-251 million years ago); while Pistosaurus belongs to stem group Plesiosauria; and both Pistosaurus and Plesiosauria belongs to clade Pistosauroidea from Triassic. Both Nothosauroidea and Pistosauroidea belong to Sauropterygia.