2016 in Review

And so we close 2016, having gone from Death Valley, to Chickasaw National Recreation Area, to Fort Union Trading Post, to Interstate State Park, and back home. We contemplated paracrinoids, waded through 19th century shenanigans, got locked in a hadrosaur, withstood earthquakes and volcanoes, and were swarmed with crocodiles. (And occasionally I filled space with a random dinosaur or some photos.)

And in honor of that, an interesting triangular fossil in Platteville building stone on the St. Paul campus of the U of M. A hyolith?

Club Late Ordovician

As I write this, it is about 10 degrees F below zero, with a windchill about 20 below. It's a good time to think about warmer things, like, well, equatorial Minnesota. When I work with the paleontology of the National Park Service, one thing I like to do is to compare fossil records across different parks. Several years ago, we combed through our various records and compiled a sort of database (okay, it's functionally almost nothing like a database, but that's the simplest way to describe it) on NPS paleontology. This compilation is such that now we can say, "Give us a rundown on all of our records for Middle Triassic park fossils," and the computer will do nothing because it isn't programmed to respond to verbal commands, but you can rest assured that we can very quickly find that information. It is therefore simple for me to pick out, say, the Late Ordovician records and make some thumbnail observations. I can thus present to you the exclusive Club Late Ordovician, as shown in the following map. (I could have called it Club Upper Ordovician, but it just didn't have the same ring.)

One of my famous giant captions. 1. Death Valley National Park (DEVA), California–Nevada; 2. Great Basin National Park (GRBA), Nevada; 3. Yellowstone National Park (YELL), Idaho–Montana–Wyoming; 4. Grand Teton National Park (GRTE), Wyoming; 5. Bighorn Canyon National Recreation Area (BICA), Montana–Wyoming; 6. Big Bend National Park (BIBE), Texas; 7. Chickasaw National Recreation Area (CHIC), Oklahoma; 8. Mississippi National River and Recreation Area (MISS), Minnesota; 9. Pictured Rocks National Lakeshore (PIRO), Michigan; 10. Effigy Mounds National Monument (EFMO), Iowa; 11. Buffalo National River (BUFF), Arkansas; 12. Hot Springs National Park (HOSP), Arkansas; 13. Stones River National Battlefield (STRI), Tennessee; 14. Natchez Trace Parkway (NATR), Alabama–Mississippi–Tennessee; 15. Katahdin Woods & Waters National Monument (KAWW), Maine; 16. Saratoga National Historical Park (SARA), New York; 17. Delaware Water Gap National Recreation Area (DEWA), New Jersey–Pennsylvania; 18. Chesapeake and Ohio Canal National Historical Park (CHOH), Maryland–Virginia–West Virginia; 19. Denali National Park & Preserve (DENA), Alaska. The gray blob over much of the eastern half of the US is the distribution of Late Ordovician bentonite beds as per Kolata et al. 1996 (also the source for the discussion of correlations below); the beds may also go somewhat farther to the west in the subsurface.

Fossil Crocs of the Science Museum

Although the dinosaurs get the most press, the Science Museum of Minnesota's paleontology department has a strongly diversified portfolio of ancient reptiles. In particular, champsosaurs and crocodyliforms (modern crocodilians and their closest extinct relatives) are well-represented in the collections and on exhibit. The Science Museum features mounts of four fossil crocs, each one filling different places in their ecosystems: an apex terrestrial/freshwater croc (Borealosuchus formidabilis), a large estuarine croc with elongate jaws living alongside whales (Gavialosuchus carolinensis), a medium-sized terrestrial/freshwater croc from a dinosaur-dominated setting ("Goniopholis"), and a house-pet-sized terrestrial/freshwater generalist (Wannaganosuchus brachymanus). This diversity shouldn't be too surprising. Crocodylomorphs, with around 225 million years of time on their hands, have done quite a bit of experimentation, including truly marine thalattosuchians and small, terrestrial, occasionally dinosaur-like "sphenosuchians".

Parksosaurus

For a small herbivorous dinosaur with no crest, horns, etc., Thescelosaurus has managed to sweep through a respectable number of species. There's the type species (T. neglectus), T. assiniboiensis, T. edmontonensis, T. garbanii, Bugenasaura infernalis, and the subject of today's entry, which entered science as Thescelosaurus warreni but which is better known as Parksosaurus (warreni or warrenae, depending on how you feel about far-after-the-fact emendations).