Sunday, June 17, 2018

Your Friends The Titanosaurs, part 1: Adamantisaurus, Aegyptosaurus, and Ampelosaurus

This is the first in what I plan as a periodic ongoing series. The response from this year's two previous titanosaur posts was better than I expected, especially considering what I thought was some dry subject matter, so if people are liking the big lugs, why not have them around more often? There are certainly plenty of species, and hopefully they don't become overwhelming if they feature once a month or so, when some other topic isn't coming together. The plan is to briefly cover three species in a post, in more or less alphabetical order. For example, in this post we have Adamantisaurus mezzalirai, Aegyptosaurus baharijensis, and Ampelosaurus atacis, taking us from Brazil to Egypt to France. The third species would have been Aeolosaurus colhuehuapensis, but because there are three species of Aeolosaurus I thought it made sense to hold it back and make the next post all Aeolosaurus. The next one would have been Alamosaurus sanjuanensis, but I have other plans for it. Therefore, Ampelosaurus atacis gets the call.

Sunday, June 10, 2018

Postglacial fragments, featuring Hartman's Cave

Although eastern North America contains many things, it is not noted for its terrestrial Cenozoic sedimentary deposits. Conditions just weren't favorable for the long-term preservation of extensive terrestrial sedimentary formations. Therefore, our knowledge of terrestrial life in this region is largely confined to some transitional coastal settings and what we might call "point sources" in comparison to the great formations of the West: sedimentary deposits of caves, fissures, bogs, ponds, and so on. These in turn are strongly biased to just the Pleistocene and Holocene. We've visited a few of these sites before, around Minnesota (Hidden Falls, I-35, Kirchner Marsh, Loring Park, and in general), and in the District of Columbia, Kentucky (Mammoth Cave), and Pennsylvania (Marshalls Creek Mastodon, Port Kennedy Bone Cave). Here is another site in northeastern Pennsylvania, plus some brief commentary on sites nearby.

Sunday, June 3, 2018

Bagualosaurus agudoensis: another sauropodomorph ahead of its time

Our subject today is the newly described Bagualosaurus agudoensis from lower Upper Triassic rocks of southern Brazil. If I'd known back in March 2016 that I'd have the opportunity in a couple of years to write about another "prosauropod" that was "ahead of its time", and that it would include a partial skull justifying a terrible "head" pun, maybe I'd have come up with another title then. Oh, well; spilled milk and all that.

Sunday, May 27, 2018

Midwest Ordovician craters: Decorah and Rock Elm

Life in the Ordovician of the Upper Midwest wasn't all warm tropical seas and all the organic particles you could filter. We've already run into giant volcanic eruptions spreading ash far and wide. There was also a significant glaciation at the end of the Ordovician; the ice itself didn't get to tropical North America, but it did lead into major extinctions. We don't have to go to the poles or volcanoes off the coast of North America for dramatic geologic events, though: we only have to go as far as west-central Wisconsin and northeastern Iowa.

Sunday, May 13, 2018

The secret identity of "Agathaumas"

If you've been at this dinosaur thing for a while, you've probably encountered this piece of Charles Knight artwork, labeled as Agathaumas:

Agathaumas, Charles Knight's work via Wikimedia Commons.

Sunday, May 6, 2018

Titanosaurs in time and space

Nothing too earth-shattering this week, just an adjunct to "Titanosaurs all the way down" featuring these lovingly crafted charts of titanosaur distribution taken from The Compact Thescelosaurus (so you know all mistakes are mine). Given 101 described species to work with, I split the titanosaurs between South America and all of the other landmasses. As with other charts, you'll need to click to embiggen.

Sunday, April 29, 2018

Tracking sloths and people at White Sands National Monument

Earlier this week came some of the biggest news concerning National Park Service paleontology in quite some time: the discovery of tracks, including overlapping tracks, of extinct ground sloths and humans at White Sands National Monument, New Mexico. These finds were published in an article by Bustos et al. (2018), which can be accessed here (don't forget the supplement; less technical summary here). It's a pretty darn substantial way of showing humans and extinct sloths as contemporaries, and new evidence on the early history of humans in the Americas and the twilight of the Pleistocene megafauna. About the only ways you could make the tracks more notable would be to have them continue into the end of a hunt, or to have some dateable material that placed them significantly pre-Clovis.

Part of Figure 2 from Bustos et al. (2018). Part B has some faint sloth tracks (when poorly preserved, it can be difficult to distinguish similarly sized human and sloth tracks). Part C shows a "flailing circle" where a sloth appears to have swung its arms at a human. Part E shows a human track inside a much larger sloth track.