Clade †Xenopsaria Phylum Chordata Rank Family | Scientific name Cimoliasauridae Higher classification Plesiosauria Order Plesiosauria | |
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Lower classifications Elasmosaurus, Futabasaurus, Kimmerosaurus | ||
Elasmosauridae was a family of plesiosaurs. They had the longest necks of the plesiosaurs and survived from the Late Triassic to the end of the Cretaceous. Their diet mainly consisted of crustaceans and molluscs.
Contents
Size
The earliest elasmosaurids were small, about 3 m (9.8 ft). At the end of the Cretaceous, elasmosaurids grew as large as 14 m (46 ft), such as Elasmosaurus. Their necks were the longest of all the plesiosaurs, with anywhere between 32 to 76 (Albertonectes) cervical vertebrae They weighed up to several tons.
Taxonomy
The family Elasmosauridae was erected by Cope in 1869, and anchored on the genus Elasmosaurus.
Phylogeny
Elasmosauridae (Cope, 1869) is a stem-based taxon defined in 2010 (and in earlier studies in a similar manner) as "all taxa more closely related to Elasmosaurus platyurus than to Cryptoclidus eurymerus, Leptocleidus superstes, Plesiosaurus dolichodeirus or Polycotylus latipinnis". The cladogram below follows, showing only Elasmosauridae interrelationships, the results of O’Gorman et al. (2015) who performed the most inclusive phylogenetic analysis focusing on Elasmosauridae interrelationships to date.