STL Science Center

STL Science Center

16 August 2013

Othniel Honored

Running herd cast at the Denver Museum of Nature and Science; Tad Williams
In 1878 Othniel Charles Marsh named a small ornithischian dinosaur Laosaurus consors; "kindred stone lizard". Since that time other species were attributed to Laosaurus by Marsh and Gilmore but subsequent and current research has determined that Laosaurus is a nomen dubium. Instead, the basal hypsilophodont Othnielosaurus consors has been renamed in honor of OC Marsh. As of 2007, the most current analysis of Othnielosaurus, Peter Galton has upheld a 1990 paper by Bakker et al that placed Othnielia, another previous placement of Othnielosaurus, in a position of being more basal than the most basal hypsilophodonts; in other words Othnielosaurus is primitive enough that it may be a common ancestor, a splitting point, of hypsilophodonts and another group of animals. Current cladograms, however, simply place Othnielosaurus at the base of a split between Thescelosauridae and Hypsilophodontidae, making them more basal than both but not a common ancestor from which the families are both derived; systematics and cladistics gets confusing rather quickly sometimes. Regardless, this is a rather basic ornisthischian dinosaur, the kind that looks like a large and active lizard and does not stand out like a Triceratops or a Dilophosaurus from the rest of the dinosaurs.

No comments:

Post a Comment