Sunday, September 18, 2016

Sunday nautiloids

An interesting fact concerning nautiloids and the Platteville Formation is that the biggest nautiloid shells are often found only partially preserved, because their diameters (up to around 10 in/25 cm) exceeded the depth of the Platteville ooze they sunk into (Webers 1972a, 1972b). This means that when you see a fossil of one of these big Platteville nautiloids where the cross-section is partly round and partly irregular, you can guess that the round part represents what was buried; the rest of it was eroded off. So, while a small nautiloid can be completely buried:


...the big guys aren't so lucky. Take these examples from Sogn, Minnesota:

The more impressive of the two, featuring the part that looks like a nautiloid.

The cross-section of this specimen. Round was down (in the mud), originally.

The cross-section of the other, less impressive nautiloid.

Half a nautiloid is better than none, and for these two nautiloids, it permits a bonus: other shells and organic fragments collected in the eroded nautiloids. Notice the off-white patch near the center of the first cross-section above? Here's a close-up:


This is a small lingulid brachiopod (modern cousin Lingula; see a larger relative from Oklahoma rocks of reasonably similar age to the Platteville here). There are several fossils larger than millimeter-sized chips visible on these nautiloids, and they all appear to be the same kind of lingulids. This is an interesting association, but I couldn't tell you what it means. Here are two of the better-preserved examples:



References:

Webers, G. F. 1972a. Paleoecology of the Cambrian and Ordovician strata of Minnesota. Pages 474–484 in P. K. Sims and G. B. Morey, editors. Geology of Minnesota: a centennial volume. Minnesota Geological Survey, St. Paul, Minnesota.

Webers, G. F. 1972b. Paleoecology of the Ordovician strata of southeastern Minnesota. Pages 25–41 in G. F. Webers and G. S. Austin, editors. Field trip guidebook for Paleozoic and Mesozoic rocks of southeastern Minnesota. Minnesota Geological Survey, St. Paul, Minnesota. Guidebook 4.

Sunday, September 11, 2016

Port Kennedy Bone Cave supplement

The National Fossil Day monthly feature for September is Port Kennedy Bone Cave, in Valley Forge National Historical Park. There is a Pleistocene theme this year, and caves are great for Pleistocene fossils. Port Kennedy Cave is the second cave-based feature I've written this year, after Rampart Cave, and the third cave feature total (we've also got Gypsum Cave). We've still got three months to go, and I could certainly see some more caves in there. Anyway, I'm writing this to direct you to a story on an unusual site (you get middle Pleistocene mammals, Edward Drinker Cope, Valley Forge, a rumored buried train, and bone preservation compared to "over-ripe pears"), and provide some supplementary material on the species described from the fissure.

Monday, September 5, 2016

Regarding Liaoningosaurus

By now you may have heard about the new paper by Ji Q. et al. on Liaoningosaurus, proposing some surprising things about the paleobiology of this ankylosaur. Andrea Cau already had a go at it over at Theropoda. I'm afraid I won't be as concise or insightful, but possible gut contents are involved, and having fought my own gut-content dinosaur to a truce, I think I can bring a distinct perspective to this paper. 

Wednesday, August 31, 2016

The Great Minnesota Brachiopod Caper of 1892

I've been looking to write something on Frederick Sardeson for a little while now, but Weiss (2000) has taken care of his biography in great detail, and there's enough going on there that to summarize it would still give you a long, long post. Instead, as I was working this particular incident stood out and volunteered to serve as a microcosm of his career. I present the Great Minnesota Brachiopod Caper of 1892. Weiss (1997) also got there before me, but this is a much more compact bite to take.

First, our cast of characters as they were in 1891–1892:
Christopher Hall, the head of the University of Minnesota's Department of Geology;
Frederick William Sardeson, former law student turned geology graduate student under Hall;
Charles Schuchert and Edward Oscar Ulrich, up-and-coming geologists/paleontologists out of Cincinnati; and
Newton Horace Winchell, the head of the Minnesota Geological and Natural History Survey.

And the situation:
Winchell was not a paleontologist, but he had a lot of fossils. In order to deal with them, he assembled a group of paleo-hotshots. For our purposes, the most significant are Schuchert, a budding brachiopod expert, and Ulrich, who could deal with a wide range of fossil groups. They'd already worked together on projects for the surveys of other states, so were experienced in this line of work. Winchell's team described hundreds of fossil species, with the culmination of their work being the great multi-volume "Geology of Minnesota" series. It is the creation of this series that led to Sardeson getting bluffed out of six brachiopod species by Ulrich and Winchell. For brevity, let us describe the events like this:

  1. Winchell brings in Schuchert to describe the numerous brachiopods.
  2. Hall directs Sardeson to bring Schuchert up to speed on the local brachs. Hall had previously worked with Winchell on the survey and dislikes him, although he is generous enough in this case.
  3. Sardeson and Schuchert have an informal deal that Sardeson will not publish any new brachiopod taxa until Schuchert has his work out.
  4. The "Geology of Minnesota" series is taking a long time to complete. The draft of the brachiopod chapter (Winchell and Schuchert 1895) is pretty much ready to go by late March of 1892, though, and Schuchert leaves town. In the meantime, Sardeson has nearly completed his graduate work, and has prepared a joint publication with Hall on the local Paleozoic rocks. An essential part of this is Sardeson's biostratigraphy, which incorporates a number of undescribed taxa. Hall insists that descriptions be published in advance of the joint paper.
  5. Ulrich finds out that Sardeson is preparing descriptions of new species, including brachiopods, which he promised not to do per point 3. This manuscript will be ready to go by early April. Winchell is not pleased by this turn of events.
  6. Winchell and Ulrich opt to extract part of the manuscript prepared by Schuchert to preempt Sardeson. It just so happens that the Winchell family owns a journal and Winchell himself is the editor (The American Geologist, which later kind of turns into The Pan-American Geologist). This is convenient. However, Sardeson's descriptive work, coincidentally enough due to be published in a journal edited by Hall (Bulletin of the Minnesota Academy of Natural Sciences), is almost ready for publication. There isn't enough time for Winchell and co. to preserve priority, or is there?
  7. Fittingly enough, on April 1, 1892, Ulrich provides Sardeson with a fake preprint of the extracted article, bluffing that it has already been mailed out. This has not happened, and in fact only two copies of the April 1 preprint are known to exist: Sardeson's copy and a copy kept by Ulrich.
  8. Sardeson's own article is mailed out April 6.
  9. An actual preprint of Winchell's article is mailed out April 21, with a note on the title page that it was first distributed April 1, 1892. The note does not explain that the distribution consisted of the single copy supplied to Sardeson.

Aftermath:
The immediate result is that perfidy is rewarded, at least as far as Sardeson is concerned; the community takes it at face value that the April 1, 1892 date on the Winchell and Schuchert article is legit. Sardeson is "scooped" on six brachiopods: Orthis minnesotensis, taken by Winchell and Schuchert's Orthis meedsi; Orthis petrae, taken by Orthis proavita; Rhynchonella sancta, taken by Rhynchotrema inaequivalis var. laticostata; Streptorhynchus subsulcatum, taken by Strophomena scofieldi; Strophomena halli, taken by Leptaena charlottae; and Zygospira aquila, taken by Hallina nicolleti. The episode does not reflect well on any of the participants: Hall forced Sardeson into the mess, Sardeson broke his word to Schuchert, and Winchell, Ulrich, and to a lesser extent Schuchert came up with a new twist on the time-honored game of "screw over the grad student". For good measure, Winchell's team also appropriated the framework of Sardeson's biostratigraphic zones without giving him much credit. In the long run, the episode blows over as another quaint example of academic hardball. Hall is more or less forgotten today. Schuchert works with the U.S. Geological Survey and the National Museum of Natural History before moving on to Yale for the long term, where he becomes the god of brachiopods and eventually makes up with Sardeson. Ulrich goes on to the USGS, where he continues working on the lower Paleozoic and unsuccessfully proposes two additional periods out of the Cambrian and Ordovician (the Ozarkian and Canadian). Winchell successfully guides the Survey work to completion, retires to archeology, gets a number of things named after him, and is now more or less the only geologist based out of Minnesota that anyone has ever heard of. Sardeson embarks on a tempestuous career.

Sardeson was the one left holding the bag, which becomes something of a pattern for him. He was a fascinating paleontologist who combined aspects of 19th century heroic geology with brilliant insights on topics such as paleobiology, paleoecology, and biostratigraphy, along with very un-19th-century ideas on when to name new species. Over several decades he amassed a collection of thousands of fossils from the Ordovician of Minnesota, carefully plotted stratigraphically. Unfortunately, for all of his gifts, he also had an uncanny knack for marginalizing himself through sarcasm, paranoia, and professional contempt. (I'm not going to get into chicken-and-egg, but the events of 1892 probably did not increase his trust in others.) He quarreled with most of the geologists he encountered and entered into several long-running feuds which, despite whatever justification, did him more harm than good. He came up with the earliest name for what we now call the Platteville Formation and Decorah Shale (Beloit Formation, 1896), but was ignored in favor of the Platteville Formation, coined years later by a USGS geologist (Bain 1905). He was prevented from working on the geology of the St. Croix Valley by Ulrich and Charles Walcott (not counting the fact that Sardeson and Ulrich were not exactly buddies, Ulrich had staked out that area as part of his turf, and Walcott was wary of anyone who might show him up in his Cambrian sections, and Sardeson did not mind showing people up). He was dismissed from the University of Minnesota in 1913 and ended up blacklisted from all of the geology journals except the eccentric Pan-American Geologist. Through it all, he displayed superhuman perseverance. He was publishing up to 1940, into his 70s.

References:

Bain, H. F. 1905. Zinc and lead deposits of northwestern Illinois. U.S. Geological Survey, Washington, D.C. Bulletin 246.

Sardeson, F. W. 1892. The range and distribution of the lower Silurian fauna of Minnesota with descriptions of some new species. Bulletin of the Minnesota Academy of Natural Sciences 3(3):326–343, 408–413.

Sardeson, F. W. 1896. The Galena and Maquoketa shales. Part 1. American Geologist 18:356–368.

Weiss, M. P. 1997. Falsifying priority of species names: a fraud of 1892. Earth Sciences History 16:21–32.

Weiss, M. P. 2000. Frederick William Sardeson, geologist 1866–1958. Minnesota Geological Survey, St. Paul, Minnesota. Bulletin 48.

Winchell, N. H., and C. Schuchert. 1892. Preliminary descriptions of new Brachiopoda from the Trenton and Hudson River groups of Minnesota. The American Geologist 9:285–294.

Winchell, N. H., and C. Schuchert. 1895. Sponges, graptolites, and corals from the Lower Silurian in Minnesota. Pages 55–95 in Lesquereux, L., C. Schuchert, A. Woodward, E. Ulrich, B. Thomas, and N. H. Winchell. The geology of Minnesota. Minnesota Geological and Natural History Survey, Final Report 3(1). Johnson, Smith & Harrison, state printers, Minneapolis, Minnesota.

Sunday, August 21, 2016

Champsosaurus: Adventures in 19th century taxonomy

It all started innocently enough with a couple of paragraphs in the 1870 Proceedings of the Academy of Natural Sciences, submitted on behalf of Joseph Leidy. The item notes that Leidy had received a reptilian vertebral centrum (the body of the vertebra, minus all the processes and such) collected by Ferdinand Vandeveer Hayden from the Moreau River, probably from Cretaceous rocks. It reminded Leidy of the vertebrae of marine reptiles, specifically Nothosaurus, so he proposed to name it Nothosaurops, type species N. occiduus. So far, so good. He got around to a longer description in 1873, in which he mostly repeated the 1870 information, but also included some figures of the fossil. Unfortunately, somebody goofed, because the text refers to something called Nothosaurus occiduus, but the plates and captions are using Nothosaurops occiduus. This would not be of much modern interest except for the fact that there is a good chance the specimen is the first described fossil of Champsosaurus.

Sunday, August 14, 2016

Fort Union Trading Post National Historic Site

About a week ago I returned from Fort Union Trading Post National Historic Site, where I'd been dispatched on official business. Fort Union Trading Post NHS, not to be confused with Fort Union National Monument in New Mexico, is located just north of the Missouri River on the North Dakota–Montana border. The reconstructed trading post itself is in North Dakota, but just barely; you can park in Montana and walk to it in less than five minutes (and gain an hour doing so, because you're also crossing time zones. Watch out for time paradoxes!). The fort was established for the American Fur Company in 1828 and lasted until 1867, after the fur boom years had passed. When people talk about forts in the American West, they often conjure images of cavalry, cattle, covered wagons, warfare with Native Americans, and so on. Fort Union, although it has appropriate prickly pears and yucca, was not a military post, although some of its building materials did become part of the Army's Fort Buford just down the river. Instead, as the name makes plain, it was a trading post, where Native Americans from many tribes traded furs for goods. At the time, it was ideally situated right above the Missouri River, but rivers get restless and this one has moved well south on its floodplain. Fort Union itself is not a hotspot for finding fossils, although an occasional inch-scale fragment of petrified wood can be seen, not an unusual thing for North Dakota (and if you do visit the fort and see such a piece, please don't take it!). However, the fort has a place in the historic development of North American paleontology.

Most of Fort Union from just outside the southwest bastion
 
This all goes back to a fortunate convergence of geography and company policy.  The AFC, via the Chouteau family, was noted for its support of artists and scientists, including such notables as John James Audubon, George Catlin, Joseph Nicollet, and Prince Maximilian of Weid, and encouraged their activities (Chaky 2015). Alexander Culbertson, the bourgeois (or manager) of Fort Union from 1837 to 1847, at times traveled from Fort Union to Fort John on the Laramie River, via Fort Pierre in what is now South Dakota. Fort John is better known as Fort Laramie, which incidentally also did not start out as an Army post, but as a fur trading post. It only became an Army post in 1849. The Fort Pierre–Fort John route took him across the Mauvaises Terres (spelled various ways in various sources), today better known as the White River Badlands. On these trips, he would occasionally collect fossils. He is probably the source of the first scientifically reported Badlands fossil, a jaw fragment which became named Paleotherium prouti and which is now known to have belonged to a brontothere (Wischmann 2000). He definitely provided the fossils that Joseph Leidy described as Poebrotherium wilsonii (a camel) and Merycoidodon culbertsonii (an oreodont, in fact "the" oreodont) (Chaky 2015), kick-starting vertebrate paleontology in the Badlands and west of the Mississippi in general. Early press on these finds in the late 1840s attracted other geologists. Among them was David Dale Owen, at that time working on a survey of Iowa, Minnesota, and Wisconsin. He dispatched subordinate John Evans to the Badlands in 1849. Evans returned with another load of vertebrate fossils which was sent to Leidy, whose descriptions of the bones makes up a chapter in Owen's massive 1852 survey publication. The AFC got into the act by sending Alexander's brother Thaddeus with another group in 1850 to make additional collections. In 1853 there was even an early foretaste of the Bone Wars when a government railroad survey crew including Evans butted heads with Ferdinand Vandeveer Hayden and Fielding Bradford Meek (Chaky 2015).

Another lasting trace of the early paleontological work in the area is the name of a rock unit that is commonly exposed in western North Dakota and eastern Montana: the Fort Union Group (North Dakota Geological Survey name) or Fort Union Formation (Montana Bureau of Mines and Geology name). This Paleocene-age sedimentary unit is the source of the Wannagan Creek fossils which can be viewed at the Science Museum of Minnesota, and makes the picturesque badlands of Theodore Roosevelt National Park and Little Missouri National Grassland. It does not appear to be exposed within Fort Union Trading Post NHS, although it is exposed in the uplands just beyond. Hayden used Fort Union as his base of operations in 1854 and early 1855, making collections of nonmarine mollusks from sites around the fort (Hartman 1999; Chaky 2015).

The Fort Union Group in the North Unit of Theodore Roosevelt NP

References:

Chaky, D. 2015. Fossils and the fur trade: the Chouteaus as patrons of paleontology. We Proceeded On 41(2):12–23.

Hartman, J. H. 1999. Western exploration along the Missouri River and the first paleontological studies in the Williston Basin, North Dakota and Montana. Proceedings of the North Dakota Academy of Science 53:158–165.

Owen, D. D. 1852. Report of a geological survey of Wisconsin, Iowa, and Minnesota; and incidentally of a portion of Nebraska Territory. Lippincott, Grambo & Co., Philadelphia, PA. Available at http://archive.org/details/mobot31753000174885 or http://books.google.com/books?id=Y_ZYAAAAYAAJ.

Wischmann, L. 2000. Frontier diplomats: Alexander Culbertson and Natoyist-Siksina' among the Blackfeet. University of Oklahoma Press, Norman, Oklahoma.

Sunday, July 31, 2016

(former) Ash beds in St. Paul

Although many Minnesotans are aware of the great Midcontinent Rift that runs across the state, it's less generally well-known that evidence of some of the largest known volcanic eruptions in the history of the planet can be found in the Twin Cities. In fact, you can easily put your hand on a layer of former volcanic ash by taking a short walk at our old friend Shadow Falls Park, at the end of Summit Avenue.