Asked by kororaa

why do the bigger theropods have those tiny holes at the front of their jaws?

The pits you see on the maxilla, premaxilla and mandible are called neurovascular foramina. Some (like the ones that run in a line on the maxilla) may have housed arteries, although the scattered foramina on the rostrum are unique to spinosaurids. Here’s an excerpt from Dal Sasso et al. (2009): “we postulate the presence of croc-like pressure receptors [in Spinosaurus], that might have given its mouth, when positioned on the air-water interface, an unexpected tactile function, useful to catch swimming preys without relying on sight.” So the foramina on the rostrum may have held pressure receptors that aided in catching prey. Pretty cool. 

Here’s a picture from Dal Sasso et al. 2005 of the rostrum of Spinosaurus (MSNM V404), showing detail of the foramina.

Posted 5 months ago — 4 notes