Friday, November 28, 2014

Thescelosaurus: hello old friend

Thescelosaurus is near and dear to my heart, and Clint Boyd's recent publication on the skull of T. neglectus (Boyd 2014) makes it a good time to ruminate on this animal. Thescelosaurus is one of the most common dinosaur genera from the end of the Cretaceous in North America, and close to a dozen good specimens have at least been mentioned in the literature, to say nothing of the plethora of stray vertebrae, teeth, and limb elements littering the Hell Creek, Lance, Scollard, Frenchman, and other formations. This set of end-Cretaceous formations in western North America is best known for Tyrannosaurus, Triceratops, and the Duckbill Formerly Known As Trachodon/Anatosaurus/Anatotitan (Edmontosaurus annectens), but your standard End-K toybox also comes with Ankylosaurus, Pachycephalosaurus, Torosaurus (depending on where you buy your toys), the original Ornithomimus, this spring's darling Anzu, various nameless dromaeosaurids (perhaps mostly Acheroraptor) and troodontids, and of course Thescelosaurus. Oddly, many of these are among the largest examples of their lineages.

USNM 7757, the type specimen of Thescelosaurus neglectus, as it had been exhibited at the National Museum of National History; we'll see how it looks after the renovation. The neck and skull are reconstructions.

This is more or less how it was found as well, with the neck and skull absent. The right leg was also repositioned (it had been disarticulated from the hip and forming a right angle with the long axis of the body). From Gilmore (1915).

Sunday, November 23, 2014

Paleontology of the Santa Fe Trail

As the note says with my bio, I am a "researcher and writer who has been helping to inventory and catalog the fossil resources of the National Park Service." A lot of the work I've done has been geared around Inventory & Monitoring networks. The I&M program groups parks with significant natural resources into networks based on their geography and the types of natural resources they contain, with geology and paleontology being among these natural resources. We are gearing up to prepare a revised and updated summary for the Southern Plains Network (SOPN), which includes 11 units in Colorado, Kansas, Oklahoma, New Mexico, and Texas. Although the I&M networks have served as the broad framework for a lot of our work, only 270 of the various units of the NPS are included. Granted, most of those that aren't included are usually small urban sites with little paleontological potential (except for fossiliferous building stone, which is more abundant than you might think; you can scarcely go past a large building in Washington, D.C., without finding Salem Limestone, aka Indiana Limestone, or in other words uncounted itty-bitty fragments of Paleozoic marine invertebrates), but it would be foolish to a priori dismiss them. Thus, when I work on a network, I also like to cover the non-network units that are geographically within that network. In the case of the Southern Plains Network, one of those is the Santa Fe National Historic Trail.

Sunday, November 16, 2014

National Park Service military sites and fossils

As of this writing, there are 403 units in the National Park System, although in practice the number of sites with some connection to the NPS is larger: there are many national trails, rivers, heritage areas, and affiliated units that are not included in that total. Of these, 252 are currently known to have some sort of paleontological resource, from the obvious (any unit with "Fossil" in the name, for example) to much more subtle occurrences, such as fossils in building stone at many East Coast units, or one unusual case in which a fossil fish (quite possibly from Fossil Butte National Monument, interestingly enough) is in the collections of Marsh-Billings-Rockefeller National Historical Park because it had been in the holdings of one of the families that had owned the site.

Sunday, November 2, 2014

Out in the fall: the southeastern metro

There is a brief period of time during the fall in the Twin Cities metro after the heat, humidity, insects, and plant growth of the summer have subsided, but before the first significant snowfall has hidden the ground. It usually starts around the middle of October and lasts until about Thanksgiving, depending on temperature and moisture. It's a great time to be outside, if you don't mind the increasing chill, and it gives you one last chance at the rocks. There's one area of bedrock outcrops on the Mississippi before we get to the confluence with the St. Croix, from about Grey Cloud Island and downstream, and we've only really stopped there once, although the rocks are covered here as well. However, there's a reason it hasn't been discussed much: there's not as much to see. If you're down in the area, though, here's the rundown: