Stegosaurus Plate
This transverse cross section of a Stegosaurus plate, partially crushed during fossilization due to its lightweight construction, reveals vascular canals in the outer bone (red/purple). The inner support structure of the plate is now filled in with a rock matrix (white). Image courtesy of Russell P. Main.
From the article:
The outer surface of the plates was covered in a large number of blood vessels, and in thin section, "pipes" or open circular spaces were apparent. If connected to the vascular network outside of the scutes, the pipes could conduct blood to be cooled or heated by the environment. But the connection between the two could not be determined based on a single plate that was examined previously.
To find the connection between the vessels and the pipes, Main and his colleagues studied not only the structures of stegosaurs, but also of related armored species including their primitive ancestor, the Scutellosaurus, the younger Scelidosaurus and the ankylosaurs, a sister group of the stegosaurs. They made thin sections of the scutes and spikes from several specimens donated by museums.
