Expert: David Prus - 6/25/2009

Question
Thank you for answering my past question:
1)Why was Rajasaurus so heavy for its length in comparison to Carnotaurus??
2)Which dinosaurs were possible prey items for Rajasaurus and Tarascosaurus??
3)Which were the apex predators in the following geological formations back then??
Kota Formation
Sânpetru Formation
Shishugou Formation
Tendaguru Formation

4)Which Abelisaurid has, in your opinion, the strongest set of jaws??

Answer
1. Rajasaurus had a proportionally larger head and slightly more heavily built than Carnotaurus with a deeper body. Furthermore, it has been measured differently that Carnotaurus. Carnotaurus' weight was based on the skeleton itself, while Rajasaurus' weight was measured from a rather beefy reconstruction made by the Indian Geological Survey.

2. Rajasaurus probably hunted the titanosaur Isisaurus and other sauropods. Tarascosaurus also lived in a titanosaur-heavy area, with species like Ampelosaurus but also some ornithopods like Rhabdodon

3) Kota Formation: The only Early Jurassic predator in India found is the scanty Dandakosaurus, a ceratosaur of some kind, perhaps an animal like Dilophosaurus. At this time, Pangea was in the process of breaking up, so it's likely that relatives of Dilophosaurus and Crylophosaurus were predators all over the globe

Sanpetru: As part of the Hateg Formation, small animals probably were the most efficient strategy. Dromeosaurus like Pyroraptor were probably the top predator.

Shishugou: There were three main predator: the allosaurid Sinraptor, the gracile primitive tyrannosaur Guanlong, and the basal allosaur Monolophosaurus. Sinraptor was the larger and probably the apex predator

Tendaguru: the two main predators are species of Allosaurus (A. tendagurensis, at 30 feet long) and Ceratosaurus (C. ingens, also about 30 feet long)

4. Since none of the Abelisaurs have jaws meant for crunching (like allosaurs, they probably used slashing bites), their jaws were fairly weak and flexible. However, based on size alone, it was probably Carnotaurus (with the measured bite force of 3000 N, and a short-skull). I suspect that Abelisaurus, Majungasaurus and Rajasaurus also had strong bites of their own