New dinosaur tribes named
4 Jan 2017 by qwqcdhhcbc.d qwqcdhhcbc.d
Scientists have named two new clades, or tribes, of horned dinosaurs based on fossils collected in the United States and Canada.
Scientists have named two new clades, or tribes, of horned dinosaurs based on fossils collected in the United States and Canada.
These horned dinosaurs (ceratopsians) were herbivorous, beaked dinosaurs that existed during Cretaceous Period. The two new tribes have been labelled Nasutoceratopsini and Centrosaurini.
They grew up to six metres long, weighed more than two tons and had large shields on the back of their skulls like Triceratops. Nasutoceratopsins are distinguished by having large, broad frills that lacked well-developed ornamentation as well as two long brow horns above their eyes.
Dr. Michael Ryan, from the Cleveland Museum of Natural History and first author, said: “We believe the skull ornamentation was important for attracting mates. If nasutoceratopsins lacked bony ornamentation, it's possible that they may have used distinctive coloration patterns, social behaviours or vocalisations, like modern birds do in their courtship behaviours. But we'll never know for sure since those latter features don't fossilise.”
Centrosaurini, the second new clade, possessed highly ornamented frills with short brow horns. The two clades were found together over a large distance in rocks of the same age suggesting they would have lived alongside one another.
Dr Jordan Mallon, from the Canadian Museum of Nature, and co-author, said: "It's probably similar to how two species of rhinoceros can broadly overlap in their geographic ranges, but do not actually compete with each other for resources. Black rhinos will feed on woody browse, while white rhinos are primarily grass grazers.
“Thus, the two species tend to utilise different parts of the same environments. The assumption that centrosaurins and nasutoceratopsins may have had different feeding strategies is supported by the fact that the two tribes had different types of jaws, with the lower jaws of nasutoceratopsins being shorter and deeper.”
These discoveries form part of the Southern Alberta Dinosaur Project, which aims to fill in knowledge gaps about Late Cretaceous dinosaurs and study their evolution.
The study was published in the Canadian Journal of Earth Sciences.
