The first tracks were found atW3 Bird site in the summer of 1998 during the large-scale mapping of the W3 Main tracksite. A faint bipedal trackway of a large theropod (Irenesauripus mclearni) marches across an intensely rippled substrate. There are also very distinct claw impressions scattered throughout the same surface, but these are most likely crocodilian swim traces.

A large theropod trackway on a rippled surface.


Claw impressions from a swimming reptile on a rippled surface.


In another area there are the footprints and trackways of small, short-legged birds which are currently being described, and also a few tracks of  large, long-legged birds (Aquatilavipes curriei). The Grande Cache tracksites are among the richest in the world for bird footprints.

Several small bird footprints (10cm scale)


A single bird footprint (scale in centimetres).