It is somewhat older than the Tyrannosaur although still of the late Cretacic period, and may have been ancestral to it.

A fine series of limbs and feet as also skull, tail, etc., are in the Museum's collections.

At or about this time carnivorous dinosaurs of slightly smaller size are known to have inhabited New Jersey; a fragmentary skeleton of one secured by Professor Cope in 1869 was described as _Laelaps_ (=_Dryptosaurus_).[10] _Ornitholestes._ In contrast with the _Allosaurus_ and _Tyrannosaurus_ this skeleton represents the smaller and more agile carnivorous dinosaurs which preyed upon the lesser herbivorous reptiles of the period.

These little dinosaurs were probably common during all the Age of Reptiles, much as the smaller quadrupeds are today, but skulls or skeletons are rarely found in the formations known to us.

The _Anchisaurus_, _Podokesaurus_ and other genera of the Triassic Period have left innumerable tracks upon the sandy shales of the Newark formation, but only two or three skeletons are known.