In Depth The original 2012 paper of the plesiosaur Spitrasaurus included the description of not one but two species for the genus. The type species, S. wensaasi (PMO 219 718) is described from sixty articulated cervical vertebrae believed to have come from a juvenile individual. S. larseni (SVB 1450) is also known from cervical vertebrae, … Read more
In Depth Augustasaurus was the second member of the Pistosauroidea group of Triassic marine reptiles discovered. Given that the first (and currently only other of known) member of the group, Pistosaurus, is known from Europe, this reveals that the pistosauroid sauropterygians had at least a reasonable geographic range. Like with Pistosaurus, Augustasaurus resembles early plesiosaur … Read more
In Depth Edgarosaurus seems to have been one of the first polycoylid plesiosaurs to swim in the late Cretaceous Western Interior Seaway, a shallow sea that submerged much of central North American during the Cretaceous. Like its relatives, Edgarosaurus had a typical plesiosaur body but a short neck an elongated jaws, features reminiscent of the … Read more
In Depth Keichousaurus looks like a miniature plesiosaur, and indeed many have looked into the possibility that it may either be a direct ancestor, or representative of an ancestral form that led to the evolution of the giant plesiosaurs. As well as resembling the later plesiosaurs, Keichousaurus may have moved like them too, using their … Read more
In Depth The type specimen of Megacephalosaurus was originally assigned to the Brachauchenius genus, leading to the idea that Brachauchenius was one of the biggest of its time. The removal of this skull has led to a size revision of Brachauchenius, and the establishment of a new genus, Megacephalosaurus. However this still means that there … Read more
In Depth Named after the legendary island of Avalon (and supposed resting place of King Arthur), Avalonnectes was a rhomaleosaurid plesiosaur. Aside from being related to the type genus of the group, Rhomaleosaurus, this meant that Avalonnectes is noted as being a genus of shorter necked plesiosaurs. Avalonnectes has been considered to be a more … Read more
In Depth Acostasaurus is a genus of pliosaur that lived during the early Cretaceous period. Acostasaurus was a small to middle sized pliosaur that seems to have differed from brachauchenisine pliosaur that were otherwise common at the time and location. This could suggest that Acostasaurus had a different lifestyle/feeding preference to other larger pliosaurs. Further … Read more
In Depth Atychodracon was originally named as a species of Plesiosaurus back in 1846 when the first specimen was described by Samuel Stuchbury. At this time Plesiosaurus had fast become a wastebasket taxon with any fossils remotely similar to Plesiosaurus being almost immediately attributed to the genus as a new species. Many former species of … Read more
In Depth Paludidraco is a genus of nothosaur known to have lived in Western European waters of the late Triasssic period. Paludidraco is thought to have been similar to the Simosaurus genus, yet while Simosaurus is thought to have been an active predator, the markedly different dentition of Paludidraco suggest a different lifestyle. The jaws … Read more
In Depth Eopolycotylus is another example of one of the short necked/long jawed polycotylid plesiosaurs of the Cretaceous era. The genus name Eopolycotylus means ‘Dawn Polycotylus’ and is a reference to the earlier appearance of Eopolycotylus in the fossil record to Polycotylus, the type genus of the Polycotylidae. The type species name honours David O. … Read more