Saturday, January 19, 2019

Your Friends The Titanosaurs, part 8: Bonitasaura, Borealosaurus, and Brasilotitan

And so we reach Part 8, otherwise to be known as "Bonitasaura and these other two." Bonitasaura is one of the best-known sauropods, even if it isn't quite a household word, and also has some unusual jaw features going for it. Brasilotitan has some of the same jaw features, but is not known from nearly as much material and came along several years later. Borealosaurus has an uncertain grip on Titanosauria, and gripping things takes some creativity when you have either no fingers or just nubs.

Sunday, January 6, 2019

Crystal Ball for 2019

So we've come to 2019. I didn't do so well last year trying to apply a system, so that's gone. I'm trying to mix it up beyond "X# of new taxa"; the problem is "X#" is so easy to define and score.

Will the coming year bring, for no obvious reason, a photo of Simosuchus? (yes)

Sunday, December 30, 2018

2018 in Review

Five years in and I still can't say all that much about what people will like. I know that dinosaur posts attract more attention than posts on other topics. "The secret identity of 'Agathaumas'" was comfortably the most viewed post of 2018, although from my point of view as the writer, I thought it was only going to be a little historical goof. "Dryosaurus elderae and the revenge of Nanosaurus agilis" attracted the most comments (side note: I noticed at SVP that several Morrison posters had Nanosaurus where Othnielosaurus or other names might have been used, so it's something that has spread quickly.) The two titanosaur posts early in the year got a good reaction ("Titanosaurs all the way down" and "Titanosaurs in time and space"), inspiring the dive into "Your Friends The Titanosaurs", which may well kill me one of these days, but it's not like I was doing anything important otherwise. On the other hand, I thought "Tracking sloths and people at White Sands National Monument" would have attracted more interest; I mean, come on, giant sloths, human tracks, it sells itself! A couple were better ideas in concept than in writing ("Fossil Bison of the National Park Service" and "'Prorichthofenia': brachiopod horn corals" come to mind), and "Decorah gastropods (and some things that look like gastropods)" was definitely more work than reward. Something else: I'm sure I've said this before, but I think I've rather thoroughly mined Twin Cities geology for topics by this point.

Saturday, December 22, 2018

Your Friends The Titanosaurs, part 7.5: Baalsaurus mansillai

So now someone has gone and published a new titanosaur that would fit in the part of the alphabet we've already covered. We'll just have to kind of wedge it in, if you can buy the idea of wedging a titanosaur into anything.

When the news that a dinosaur named Baalsaurus had been published broke Monday on the Dinosaur Mailing List (thanks to Ben Creisler for keeping us all up to date!), I immediately wondered what the connection was with Baal, the Phoenician fertility god moonlighting as an Abrahamic heavy. (Spoiler: it's secondhand—"Baal" is the name of the locality.) I wasn't expecting a medium-sized, square-jawed, seemingly inoffensive South American titanosaur. Still, it works in a certain theological sense. Looking at it from a Phoenician point of view, titanosaurs clearly were doing something right with regard to fertility, so it's entirely appropriate for Baalsaurus to be a titanosaur. From the demonic usage of Baal, if you were thinking Baalsaurus would be something a bit more "heavy metal album cover", sure, you'd be disappointed. On the other hand, if you accept the proposition that forces of evil and suffering in the world are generally much more mundane than supernatural humanoids, a titanosaur is more fitting than a slavering theropod.

Sunday, December 16, 2018

Your Friends The Titanosaurs, part 7: Barrosasaurus, Baurutitan, and Bonatitan

We come now to a sauropod that acts as a titanosaurian frame of reference (Baurutitan britoi), a sauropod that gets overshadowed by another sauropod with a very similar name (Bonatitan reigi), and Barrosasaurus casamiquelai, which is kind of stuck waiting for the rest of Titanosauria to get sorted out.

Sunday, December 9, 2018

Ordovician updates

A few miscellaneous items to clear out of my Ordovician inbox, involving new members of Club Late Ordovician, conulariids, and pseudofossils:

Camp Nelson National Monument

Since we were introduced to Club Late Ordovician two years ago, two more parks have joined this exclusive organization for National Park Service units that include fossiliferous Upper Ordovician rocks. One is Saint Croix National Scenic Riverway, thanks to some isolated occurrences of the Platteville and Decorah that were protected from erosion by ancient faulting along the St. Croix Valley. These outliers represent the most northerly and landward outcrops of these formations, and are worth a post of their own at some point. The other new member is the newest NPS unit, Camp Nelson National Monument in Kentucky.

Right on cue, it's a map with a giant caption! (It's the map from the 2016 post with the two new points added, #9 and #14.) 1. Death Valley National Park; 2. Great Basin NP; 3. Yellowstone NP; 4. Grand Teton NP; 5. Bighorn Canyon National Recreation Area; 6. Big Bend NP; 7. Chickasaw NRA; 8. Mississippi National River and Recreation Area; 9. Saint Croix National Scenic Riverway; 10. Pictured Rocks National Lakeshore; 11. Effigy Mounds National Monument; 12. Buffalo National River; 13. Hot Springs NP; 14. Camp Nelson NM; 15. Stones River National Battlefield; 16. Natchez Trace Parkway; 17. Katahdin Woods & Waters NM; 18. Saratoga National Historical Park; 19. Delaware Water Gap NRA; 20. Chesapeake and Ohio Canal National Historical Park; 21. Denali NP & Preserve. The grey blob is the known extent of the Deicke K-bentonite.

Camp Nelson is rather more famous for its Civil War history, but the Camp Nelson area is also notable for its geology. In fact, per Andrews (2005), "Because of the quality of exposures, accessibility, and the importance of the site in research and geologic education, the Kentucky Society of Professional Geologists has named the Camp Nelson area as Distinguished Geologic Site 2."

The park overlays four Ordovician formations, in ascending order the Camp Nelson Limestone, Oregon Limestone, Tyrone Limestone, and Lexington Limestone (Wolcott 1969). They are all examples of your classic marine Ordovician limestones; no points for guessing that brachiopods and nautiloids are implicated in Camp Nelson NM joining Club Late Ordovician. (Not surprisingly, these limestone formations are also karst-formers, and caves and sinkholes are common in the area.) The Tyrone Limestone is known to include the Deicke K-bentonite (Kolata et al. 1996), making it partially correlative in time to the Decorah Shale. Redating of the Middle/Late Ordovician boundary may in fact put all four of these limestones into the Late Ordovician.

As the name indicates, the Camp Nelson Limestone was described from the area of Camp Nelson (Miller 1905); the type locality is a little to the south of the monument, around the area of the Kentucky River crossing. You can also find some nice faulting on the south side of the river (Andrews 2005). The Camp Nelson Limestone appears to be the oldest formation exposed in Kentucky. This was a bit surprising to me, and leads to the reflection that, thanks to accidents of geography and erosion, the bedrock at the surface in the entire state of Kentucky is younger than most of the bedrock exposed in Minnesota.

Hiding conulariids

I really hope to have a more complete update later, but suffice it to say that while tracking down references to a conulariid species from the Grand Canyon, I stumbled across George Winston Sinclair's 1948 thesis on conulariids. In this thesis there is a great deal of information about Minnesota's Ordovician conulariids that Sinclair did not publish in his lifetime, including several unpublished species. There is also the implication that at one time the University of Minnesota collections contained two-to-three-dozen conulariid specimens from the Glenwood Formation on up. This came as a surprise, because I did not recall having seen more than a half-dozen or so on my trips. Several possibilities presented themselves:
  • The conulariids were being kept separately from the other fossils when I visited, or were just somewhere I hadn't known to look;
  • The conulariids have been lost or stolen: if so, not much more can be added;
  • The conulariids passed into Sinclair's hands: this seemed worth following, because Sinclair built up a collection of conulariids and I knew that certain elements of the University of Minnesota collections had gone to others. For example, material from Berkey's Taylors Falls work was donated to the Smithsonian in recent years (Yochelson and Webers 2006).
I checked with folks at the University of Minnesota, University of Michigan Museum of Paleontology, and the Canadian Museum of Nature (the latter two institutions associated with Sinclair), but no luck to date. Hopefully this all works out in the wash. By way of apology, here's a photo of the type specimen of Ctenoconularia obex, one of the few Minnesota species Sinclair ended up publishing.

UMPC 6608, holotype of the conulariid Ctenoconularia obex, from the "Sprechs Ferry" (=lower Decorah) of Minneapolis.

One other conulariid note:
It turned out that one of the other conulariids Sinclair named came from the St. Peter Sandstone of Minnesota: Climacoconus humilis, described in Sinclair (1942) and promptly forgotten by virtually the entire universe (it's based on Carnegie Museum 4753 from Faribault, by the way). Maybe it's just my myopia showing, but it doesn't seem right that it's made almost no impression in the literature, even to be refuted. We are, after all, dealing not only with the St. Peter Sandstone, famous for having practically no body fossils, but also an uncommon and distinctive type of fossil!

Dystactophycus revisited

Back in July 2016, I showed a photo of a strange rock with concentric rings, which provided an excuse to riff on Dystactophycus, a possible trace fossil of a swirling crinoid. At the time, I thought it was unlikely that the photographed rock was Dystactophycus, or indeed of organic origin at all. A few months ago, the collector confirmed my general suspicions: he told me that mutual acquaintances have identified it as a modern fracture pattern, consistent with his later observations of features produced by air hammers punching into the Platteville.

References

Andrews, W. M., Jr. 2005. Geology and the Civil War in central Kentucky: Camp Nelson. Field Trip Guidebook, American Institute of Professional Geologists 42nd Annual Meeting.

Kolata, D. R., W. D. Huff, and S. M. Bergström. 1996. Ordovician K-bentonites of eastern North America. Geological Society of America, Boulder, Colorado. Special Paper 313.

Miller, A. M. 1905. The lead and zinc bearing rocks of central Kentucky, with notes on the mineral veins. Kentucky Geological Survey, Lexington, Kentucky. Bulletin 2.

Sinclair, G. W. 1942. The Chazy Conularia and their congeners. Annals of the Carnegie Museum 29(10):219–240.

Sinclair, G. W. 1948. The biology of the Conularida. PhD Thesis. McGill University, Montreal.

Wolcott, D. E. 1969. Geologic map of the Little Hickman Quadrangle, central Kentucky. U.S. Geological Survey, Washington, D.C. Geologic Quadrangle Map 792. Scale 1:24,000.

Yochelson, E. L., and G. F. Webers. 2006. A restudy of the Late Cambrian molluscan fauna of Berkey (1898) from Taylors Falls, Minnesota. Minnesota Geological Survey, St. Paul, Minnesota. Report of Investigations 64.

Sunday, December 2, 2018

Photos from Albuquerque

Back in October I attended the annual meeting of the Society of Vertebrate Paleontology, held at Albuquerque, New Mexico. The meeting was co-hosted by the New Mexico Museum of Natural History and Science. Part of the program of the annual meeting is a reception at a co-hosting institution, where the attendees can mingle among the institution's exhibits. I was fortunate enough to be in the company of JP and Sarah Hodnett, who are very familiar with the museum. (In fact, we'd actually spent most of that day there already, working the National Fossil Day event.) Thanks also to JP and Sarah for helping me get around Albuquerque!

We also had the able assistance of ceratopsids for National Fossil Day.