Irenesauripus is a type of ichnogenus, also known as a trace fossil or ichnofossil. Specifically, it is a kind of dinosaur footprint from the Cretaceous of North America. It was first discovered in the 1930's in Peace River, British Columbia, but has since been recorded in Alberta, the Yukon, and Texas. Albertan Irenesauripus tracks are typically found in the area of Grand Cache. These fossils are all three-toed and found in trackways. They represent an animal that walked on two legs (bipedal), walked on its toes (digits) rather than flat-footed, and had widely spaced impressions of the toes. They have evenly distributed weight, and show evidence of claws on each toe. In the original description, it was described as a theropod, and several studies have since agreed [1-3] while one has even gone further in declaring it a member of the Megalosauroidea . These prints represent large theropods, as they are typically 28-40 cm in length.
|Example of Irenesauripus from Richard McCrea|
That's it for this week. Hopefully we introduced you to another side of palaeontology that you may not have thought about before, as well as a new area in Alberta where dinosaur fossils can be found! Stay tuned for 'J' next week, which unfortunately will be from outside of Alberta.
Other 'I' dinosaurs from Alberta:
Ichthyornis - a bird (remember, birds technically are dinosaurs!)
1. Kuhn, O. 1963. Pars 101. Ichnia Tetrapodorum. In F. Westphal (ed.), Fossilium Catalogus. I: Animalia. Ysel Press, Deventer, Netherlands. 176 pages
2. M. G. Lockley. 1992. Cretaceous dinosaur-dominated footprints assemblages: their stratigraphic and palaeoecological potential. In N.J. Mateer & P.-J. Chen (eds.) Aspects of Cretaceous Geology. China Ocean Press, Beijing, 269-282.
3. Gangloff, R. A., et al. 2004. An early Late Cretaceous dinosaur tracksite in central Yukon Territory, Canada. Ichnos 11: 299-309.
4. Haubold, H. 1971. In O. Kuhn (ed.) Handbuch der Palaeoherpetologie. Part 18. Ichnia Amphibiorum et Reptiliorum Fossilium. Gistav Fischer Verlag, Stuttgart. 1-124.