A new marine reptile from the Triassic of China, with a highly specialized feeding adaptation.
The Luoping fauna (Anisian, Middle Triassic) is probably the oldest of Triassic faunas in Guizhou-Yunnan area, China. The reptilian assemblage is comprised of ichthyosaurs, a number of sauropterygians (pachypleurosaur-like forms), saurosphargids, protorosaurs, and archosauriforms. Here, we report on a peculiar reptile, newly found in this fauna. Its dentition is fence or comb-like and bears more than 175 pleurodont teeth in each ramus of the upper and lower jaws, tooth crown is needle-like distally and blade-shaped proximally; its rostrum strongly bends downward and the anterior end of its mandible expands both dorsally and ventrally to form a shovel-headed structure; and its ungual phalanges are hoof-shaped. The specializations of the jaws and dentition indicate that the reptile may have been adapted to a way of bottom-filter feeding in water. It is obvious that such delicate teeth are not strong enough to catch prey, but were probably used as a barrier to filter microorganisms or benthic invertebrates such as sea worms. These were collected by the specialized jaws, which may have functioned as a shovel or pushdozer (the mandible) and a grasper or scratcher (the rostrum). Our preliminary analysis suggests that the new reptile might be more closely related to the Sauropterygia than to other marine reptiles.
Wuhan Institute of Geology and Mineral Resources, 69 Gangyao Road, Wuhan, 430223, People's Republic of China, clong@cgs.cn.
Long
L
Cheng
Xiao-Hong
XH
Chen
Qing-Hua
QH
Shang
Xiao-Chun
XC
Wu
D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D059001:Aquatic Organisms; D002681:China; D003817:Dentition; D005580:Fossils; D007568:Jaw / Q000033:anatomy & histology; D012104:Reptiles / Q000033:anatomy & histology* / Q000145:classification*; D013045:Species Specificity; D014070:Tooth / Q000033:anatomy & histology