|
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