Internal vascularity of the dermal plates of Stegosaurus (Ornithischia, Thyreophora) |
| |
Authors: | James O Farlow Shoji Hayashi Glenn J Tattersall |
| |
Institution: | (1) Department of Geosciences, Indiana-Purdue University, 2101 East Coliseum Boulevard, Fort Wayne, IN 46805, USA;(2) Department of Earth and Planetary Sciences, Graduate School of Science, Hokkaido University, N10 W8, Sapporo 060-0810, Japan;(3) Department of Biological Sciences, Brock University, St. Catharines, ON, Canada |
| |
Abstract: | X-ray computed tomography and petrographic thin sectioning were used to study internal features of the plates of the thyreophoran
dinosaur Stegosaurus and the osteoderms of Alligator. Infrared thermographic imaging of basking caimans was used to examine possible differential blood flow to osteoderms and
other parts of the skin. Multiple large openings in the Stegosaurus plate base lead to a linear, mesiodistally oriented vestibule, which in turn apically sends off multiply branching “pipes”.
The pipes are best developed in the basal half of the plate, and communicate with cancellous regions (some of which presumably
were vascular spaces) throughout the plate interior. Some internal vascular features also connect with vascular pits and grooves
on the plate surface. Alligator osteoderms show a similar internal vascularity. In crocodylians, the osteoderms serve as armor
and help to stiffen the back for terrestrial locomotion, but their vascularity enables them to be used as sources of calcium
for egg shelling, as sites of lactate sequestration, and possibly for heat exchange with the external environment, as suggested
by our infrared thermographic imaging of basking caimans. Thyreophoran osteoderms presumably had multiple functions as well.
In Stegosaurus the potential thermoregulatory role of the plates may have been greater than in other thyreophorans, by virtue of their extensive
external and internal vascularity, their large size, thin cross-sections above the plate base, dorsal position, and alternating
arrangement. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|