Hell Creek Formation Life: Frequently Asked Questions

Hell Creek Formation Life: Frequently Asked Questions
Q: Why on earth would anyone create such a list of animals and plants found in only one layer of rock?

A: That's a good question! Because of my geology training, I tend to think of early life in terms of it's stratigraphic context, and I became interested in creating such a list about 10 years ago while working on a soil-stability project in eastern Montana. The Hell Creek Formation has interested me because it forms beautiful badlands and because it has been one of the most intensely studied rock units in North America. Therefore, there is a lot of published information on the fossils that it contains. Usually, this information is quite scattered throughout the scientific literature. Some of these sources are obscure. I have seen very partial flora and fauna lists of the Hell Creek Formation before, but nothing as complete as I wanted. I also wanted to create a concise, updatable list that could be useful to anyone studying the paleoecology of the Formation. Since the K/T boundary is found within the Hell Creek Formation, anyone working on an extinction study may find this list (and it's references) particularly useful. Others may not. To each his/her own. :-)

Q: What was the habitat like in Montana and the Dakotas back in the latest Cretaceous?

A: There is widespread agreement that the Hell Creek Formation was deposited in a well-drained, semi-tropical (humid) environment with abundant rivers and with open forests. It was NOT swampy. Seasonal weather change was very mild.

Q: Why did you just make it a Montana/Dakotas list? Why not include other states/countries that have rocks of the same age?

A: As I noted above, the list is primarily meant to be an ecosystem compilation: a listing of all living things that have been reported from a particular spot on the planet and a particular point in time. Within that context, it is scientifically useful. Many of these animals and plants probably interacted with each other on a daily or a seasonal basis. The dinosaur species, in particular, seem to be common to Montana and the Dakotas. However, taking geographic liberties has it's limits. For instance, if I had added the latest Maastrichtian flora and fauna from the Lance Formation, I may no longer have an accurate ecosystem list. Instead, I may have a list of plants and animals that may not have interacted with each other. Furthermore, it appears that the Lance Formation in southern Wyoming and Colorado may have been deposited in a slightly drier climate than was the Hell Creek Formation. Buck and Mack (1995) have found evidence that the Hell Creek-correlative McRae Formation in south-central New Mexico was deposited in an arid environment. Even a slightly drier climate could significantly change the populations, population ratios, and bio-diversity.

Reference: Buck, B.J., and G.H. Mack. 1995. Latest Cretaceous (Maastrichtian) aridity indicated by paleosols in the McRae Formation, south-central New Mexico. Cretaceous Research 16(5): 599-572.

Q: What about the life that existed on the "other side" of the K/T boundary? When are you going to compile that list?

A: Whew!! You folks don't realize how much work it can be to dig through myriad obscure paleontology journals, looking for key words like "Hell Creek", and extract any new species names buried within the reams of pages! Seriously, it is sort of fun to add to the list, but it can be time-consuming to get the project started. Presently, I don't have time to compile a life-list for the overlying Paleocene-age Tullock Formation. Maybe someone else can take up the challenge!

Q: Please put more pictures of some of the plants and animals on your web page.

A: I will do my best. However, my web provider only allocates a small amount of space for personal web pages and e-mail cache, combined (1MB). I still have room for more .jpgs, and I will be putting up some more fossil photos. But you won't see many .jpgs of life restorations. This is primarily a paleontology (fossil) page. Besides, there are many other paleo web sites that contain good quality paleo-art.

Q: Technical question: why don't you create a subpage for each group of animals/plants?

A: Obviously, it would be a better situation for the net-surfer, I agree. I chose not to break-up the list because I consider it to be one document. It is copy-righted as one entity. I fear that if I put each group of animals on their own subpage there exists a small possibility that web search engines may link to only one of the subpages and not to the other subpages. The same concern applies to bookmarks on people's home computers. Regardless of whether that possibility is remote or not, I don't want my Hell Creek list fragmented. The list would lose nearly all of it's scientific value. However, I have added internal links in the document, and that should make it a lot easier for visitors to find their way around.

Q: How did you find all the information for your list?

A: I get the information from technical journal articles and word of mouth; the references to which are usually provided to me by both professional and amateur paleontologists. So if you know of some Hell Creek Formation species that I have overlooked, please let me know! I can be reached at: bigelowp AT juno DOT com