In Depth Fresnosaurus was a late Cretaceous era elasmosaurid plesiosaur that seems to have the signature feature of this group of a very long neck proportionately greater than in earlier and more primitive plesiosaur forms. Like with these other genera, Fresnosaurus was probably a specialist hunter of fish and soft bodied cephalopods like squid. Fresnosaurus … Read more
In Depth Albertonectes is one of the best preserved elasmosaurid plesiosaurs to be discovered in Canada, and has a total of 76 cervical (neck) vertebrae . Elasmosaurid pesiosaurs like Albertonectes are noted for having their long necks that are proportionately much longer than earlier plesiosaur types. This would have been a specialist feeding adaptation allowing … Read more
In Depth Described from a single partially preserved skull, Alexandronectes was an elasmosaurid plesiosaur that swam in the waters around what is now New Zealand during the late Cretaceous. These were dangerous waters as fossils of large mosasaurs such as Taniwhasaurus are also known from the same formation as Alexandronectes, and these predators were certainly … Read more
In Depth With remains that were found in Campanian age rocks Terminonatator was possibly one of the last elasmosaurid plesiosaurs to swim in the ocean. This is a far cry away from the Jurassic heyday of the plesiosaurs when they were one of the most common types of marine reptile in the ocean. In the … Read more
In Depth Fluvionectes is a genus of elasmosaurid plesiosaur that lived in North America during the late Cretaceous. The first fossils of this genus were recovered from the Dinosaur Park Formation in Canada, a location that has yielded numerous though fragmentary and scattered plesiosaur fossil for some time. Perhaps the most stand out fact about … Read more
In Depth Nakonanectes is a genus of elasmosaurid plesiosaur that would have hunted in the Western interior seaway during the late Cretaceous period. Nakonanectes is noted for having short cervical vertebrae and an estimated length of only about five and a half meters at most for the holotype individual. This is small for an elasmosaurid … Read more
In Depth Aphrosaurus seems to have been a middle sized lightweight elasmosaurid plesiosaur. Elasmosaurid plesiosaurs (those similar to Elasmosaurus) are known for having proportionately long legs, and like with others, half of the total length of Aphrosaurus was neck. This neck was one of the primary feeding adaptations that would have allowed it to reach … Read more
In Depth Callawayasaurus was originally known as a species of Alzadasaurus until Kenneth Carpenter studied the remains and found that they actually represented a new genus. On a related note the type specimen of Alzadasaurus today only exists as a synonym to Thalassomedon and Styxosaurus. Carpenter named the new genus in honour of fellow palaeontologist … Read more
In Depth Because the holotype specimen of Morenosaurus is incomplete, it is hard to establish a precise classification of his plesiosaur, especially since the skull is unknown. It is probable however that Morenosaurus is an elasmosaurid (similar to Elasmosaurus) since these were the dominant kinds of plesiosaurs during the late Cretaceous. Additionally if this is … Read more
In Depth Although Alexeyisaurus was described from partial remains, it seems that further material was actually present at the site of its discovery. Still, the material recovered is enough to suggest that Alexeyisaurus is one of the earliest known elasmosaurid plesiosaurs, the group of plesiosaurs that had proportionately much longer necks than the more ‘standard’ … Read more