Sunday, April 16, 2017

Mea culpa and Moabosaurus

I apologize for having been light on the whole "Minnesota" and "invertebrates" part of the blog for this year. Having been doing this for a few years now, the low-hanging fruit is picked, and of course the winter is not the best time to be out and about in the rocks, even if "winter" came with quotation marks instead of snow this year. I'm currently on a short trip to Reston, Virginia, to do some work at the USGS, but I thought I'd at least try to put in something relevant for those topics. Then, of course, there’s a sauropod.

Sunday, April 9, 2017

David Dale Owen and the first geological survey of Minnesota

Although Keating, Featherstonhaugh, and Nicollet made significant contributions to Minnesota geology, the first true geological survey in what is now Minnesota would have to wait until 1847. At this point, the future state was split between Wisconsin Territory and a leftover chunk of Iowa Territory, and with the pending organization of Wisconsin into a state it was actually touch-and-go for a while how the boundaries would fall out. The convergence of St. Croix Valley interests versus the rest of Wisconsin with the old Northwest Territory stipulation that a maximum of five states be made out of the territory, and a dash of underlying slave state versus free state politics, could have led to anything from a super-Wisconsin incorporating much of what is eastern Minnesota to a separate state centered on the St. Croix Valley with Stillwater as the capital (the story can looked at briefly here). Anyway, in 1847 Congress authorized a geological survey in Minnesota and neighboring areas, and appointed David Dale Owen to conduct the work (Hendrickson 1945).

A portrait of Owen, found on p. 206 of Owen (1852).

Sunday, April 2, 2017

The return of "Anatomical terms of location"

Having done a relatively large number of dinosaur-related posts in the past few months, I've found myself running into anatomy and anatomical terms of location (dorsal, lateral, etc.). Given that not everyone knows all about the jargon, parenthetical glosses tend to slow things down, and I had perfectly serviceable glossaries for these subjects on the late Thescelosaurus!, I decided to revisit that information. I've started by putting the anatomical terms of location on their own separate page. Wikipedia has a useful summary as well, but if you aren't a wiki fan, like having the information on hand here, or just like diagrams featuring the excellent Wild Safari Sauropelta, this is for you. Eventually, I plan to put up skeletal anatomy as a page, and probably a geologic time scale as well (or at least a link to one).

Sunday, March 26, 2017

Five minutes with Ornithoscelida

If you are the kind of person who reads a blog like this, you've probably already heard the news about a new analysis (Baron et al. 2017) finding that sauropodomorphs and theropods may not be the closest of evolutionary siblings, as we've long believed. Instead, theropods were paired with ornithischians, and Sauropodomorpha got to pair with the herrerasaurids in the settlement. For the new alliance of bitey (theropod) and beaky (ornithischian) dinosaurs, the authors went back into the mists of time and pulled out Ornithoscelida, a name first proposed by Thomas Henry Huxley for a roughly similar grouping of dinosaurs. There has already been a lot of discussion about the publication, and apart from some criticisms of the exclusion of certain forms and how names were redefined, the tone at this moment is open-minded.

The idea that the relationships of the three major lineages of (non-avian, or "classic") dinosaurs are not what we thought them to be is not far-fetched. The earliest theropods, sauropodomorphs, and ornithischians all had the same grandparents, so to speak. Unsurprisingly these early forms all look kind of similar, had similar lifestyles, and thus are liable to be mixed up by later observers, especially when the observation is happening 230 million years later and the subjects have been reduced to skeletons. (It's a common problem for species near the base of branching lineages to be difficult to place.) Going from (S+T)+O to S+(T+O) does require some rethinking on how and when certain features appeared. It also throws a bit of a kink into the branch-swapping basal saurischians: Eoraptor, herrerasaurids, and friends. Eoraptor had seemed reasonably comfy among the sauropodomorphs and herrerasaurids with the theropods, and here they are switching places.

There is also an interesting question concerning the origin of ornithischians. Historically, Triassic ornithischians have been a problem due to their frustrating insistence on not being there. After a few decades of redating various formations and reassessing a bunch of teeth, we're down to Pisanosaurus (which is itself attracting questions) and Eocursor. Woo-wee. Under the traditional Saurischia–Ornithischia split, there should be more Triassic ornithischians, because of the record of Triassic saurischians. Pairing ornithischians with theropods has the potential to resolve this if it should turn out that ornithischians and theropods actually branched later in the Triassic (which also results in some "theropods" becoming basal ornithoscelidans, but it's not as if current basal theropods haven't been living under taxonomic instability). The results of the current study don't support this, but you never know. (In fact, the authors find that ghost lineages may go back all the way to nearly the beginning of the Triassic, because Nyasasaurus has suddenly started acting like a massospondylid, but then again the rocks it came from may be younger than currently thought.)

At any rate, an injection of controversy is good for the field. Either other studies support the authors, in which case we learned something new, or they don't, in which case the authors got people looking at dinosaur relationships and evolution from new angles, which is also good. In fact, now that I'm thinking about it, it's kind of odd that we have as much consensus as we do. Off the top of my head, for persistent trouble spots we've got Triassic groups and species that can't seem to make up their minds about where they belong, megaraptorans as carnosaurs or coelurosaurs, the knot of undecideds where Dromaeosauridae, Troodontidae, and birds meet, and what to do with various "hypsilophodonts". This doesn't count a few other areas that are questionable because of lack of attention, like the Box of Mystery that is Titanosauria.

All that said, I *am* going to let the issue sit before, say, updating The Compact Thescelosaurus; publications find things all the time that are not supported by later analysis (hey, Phytodinosauria, the hip alternative of the '80s and '90s). Also, redefining Saurischia to hold just sauropodomorphs and herrerasaurs was a mis-step. Just let herrerasaurs into Club Sauropodomorpha, let Saurischia go into dignified retirement, and call it a day.


Baron, M. G., D. B. Norman, and P. M. Barrett. 2017. A new hypothesis of dinosaur relationships and early dinosaur evolution. Nature 543(7646):501–506.

Sunday, March 12, 2017


Two dinosaurs were published on February 16, 2017. One of them was Isaberrysaura mollensis, which has gotten a lot of press because it's a weird basal ornithischian with gut contents. The other was Xingxiulong chengi, which hasn't gotten as much attention, although the Wikipedia article is pretty extensive. Xingxiulong is among what we used to call "prosauropods", now known as basal sauropodomorphs. It is represented by most of the skeleton, excepting the tips of the jaws, most of the hands, and the coracoids and sternal elements. It also provides me a half-point on my prediction for "prosauropods", which I'll take because it's been kind of a slow year so far.

Sunday, March 5, 2017

Joseph Nicollet

Judging by place names, Joseph Nicollet must have been a much more popular man than George William Featherstonhaugh. (Or maybe it was just the fact that it took sixteen letters to spell George's name while only taking seven to say it that proved unappealing.) I'm not sure if anyone in Minnesota attached George's name to anything, whereas Nicollet is the namesake for such pieces of geography as Nicollet County, Nicollet Mall, and Nicollet Island. His name was even attached to a ballpark, the long-time home of the old Minneapolis Millers, although probably the adjacent Nicollet Avenue was the main inspiration.

Sunday, February 26, 2017

Subsurface paleontology of Lafayette Square and the Washington Monument

Washington, D.C. is not generally ranked in the first order of fossiliferous areas. It can hardly be considered a bust, though. The "Middle" Cretaceous Potomac Group (due to a tragic geologic oversight, there is no formal Middle Cretaceous) has been reasonably kind for plants; see Fontaine (1889, 1896), Knowlton (1889), Ward (1895), Ward et al. (1905), and Sinnott and Bartlett (1916) for some of the gory details. Something you may notice from that list is that all of those publications are at least a century old. The obvious problem is that Washington is a city first and foremost, so it's not like there are a lot of outcrops for prospecting any more. The Potomac Group has also produced some scrappy dinosaur remains, and anywhere that the Potomac River once flowed is liable to have cobbles with Skolithos tubes, eroded from Cambrian rocks up in the mountains. The classic Potomac Skolithos cobbles are rounded pieces of orangeish quartzite with simple vertical Skolithos burrows, similar to skinny pencils and with a tendency to stand out from the host rock. Washington is also blessed with a profusion of fossiliferous building stone, particularly the inevitable "Indiana Limestone" (Salem Limestone). But I digress. In a city, we cannot come to the outcrop, so the outcrop must come to us. This is where subsurface explorations come in handy. We talked about taking cores from lake sediments a few weeks ago. The subsurface of Washington, like any major city, has been picked at innumerable times, uncovering fossils from places such as just north of the White House and near the Washington Monument.

Sunday, February 19, 2017

Isaberrysaura, and the further revenge of gut contents

This week saw the publication of two new dinosaurs. Both of them have something to recommend them, but given my own preoccupations we'll have to leave Xingxiulong for someone else, or for another time. (Feel free to hop over to the paper, though!) Instead, we shall meet Isaberrysaura mollensis, a basal ornithischian packing an identity crisis and a belly full of seeds.

Saturday, February 11, 2017

George William Featherstonhaugh

I've been looking at some of the early geological expeditions in the United States for work, and I thought I'd take a couple of posts to look at some of the pre-Civil War geologists who visited the Twin Cities area of Minnesota. We've already briefly looked at William Keating and the Stephen Long expedition of 1823, so I thought I'd move on to the next figure of note, George William Featherstonhaugh.

George William Featherstonhaugh, borrowed from Wikimedia Commons, who borrowed it from the Minnesota Historical Society.

Sunday, January 29, 2017

Kirchner Marsh and the use of lake sediments

As we've seen from time to time with packrat middens, there are many ways of looking at past ecological conditions. A common method in more humid environments that the deserts and mountains of the Southwest is studying lake deposits, which is quite well-suited to the Land of 10,000 Lakes. Many types of paleoecologically useful fossils can be extracted from lake sediments, ranging from diatoms ("algae" with silica cell walls), to spores and pollen, to mollusks, to ostracodes, to the jaw parts of certain midge larvae. (There are, of course, other kinds of fossils that can be found in lakes, but they aren't as commonly used for paleoecological work. A single mammoth, while certainly of great interest, is not as versatile for this kind of thing as innumerable pollen grains spread over thousands of years.) Spores and pollen are part of a group of fossils known as palynomorphs, organic-walled microfossils. There are several other types of palynomorphs, including various cysts and so forth, but for the purposes of upper Pleistocene and Holocene lake sediments in Minnesota, spores and pollen are clearly the stars of the show.

Sunday, January 22, 2017

Mammoth roundup

A couple of new publications concerning mammoths in National Park Service units have crossed my desk recently, so it seemed like a good opportunity to say a few further words on behalf of extinct proboscideans in the National Parks. I present to you first the finely wrought map below, which shows the various parks where body fossils of mammoths, mastodons, and their friends have been reported. At press time, there were 37 parks, monuments, and so forth with confirmed records, and another six with possible records (cases where the locality is not clear). This map has the novelty of differently colored and shaped symbols, which aside from providing a splash of color, show a preponderance of mastodons in the northeast and mammoths in the southwest. I've relied on the literature and such, so there's definitely the chance that some of the "mammoths" are mastodons, and vice-versa. Most of these records are from the Pleistocene, but there are a few that are older; notably, John Day Fossil Beds National Monument and Niobrara National Scenic River have both gomphotheres and mastodons of pre-Pleistocene age. The great majority of the mammoth reports in the lower 48 are likely Columbian mammoths, Mammuthus columbi (M. exilis of Channel Islands National Park being a notable exception), but given the ambiguities in North American mammoth taxonomy, I figured it wasn't worth the time to try to split them up.

I use the base map a lot, don't I? Definitely a "click to embiggen" this time, to enjoy the various colored symbols. Inventory of points: 1) Nez Perce National Historical Park, multiple states; 2) John Day Fossil Beds National Monument, Oregon; 3) Hagerman Fossil Beds National Monument, Idaho; 4) Lava Beds National Monument, California; 5) Golden Gate National Recreation Area, California; 6) Death Valley National Park, California–Nevada; 7) Tule Springs Fossil Beds National Monument, Nevada; 8) Lake Mead National Recreation Area, Arizona–Nevada; 9) Mojave National Preserve, California; 10) Channel Islands National Park, California; 11) Santa Monica Mountains National Recreation Area, California; 12) Joshua Tree National Park, California; 13) Noatak National Preserve, Alaska; 14) Kobuk Valley National Park, Alaska; 15) Bering Land Bridge National Preserve, Alaska; 16) Denali National Park and Preserve, Alaska; 17) Yukon-Charley Rivers National Preserve; 18) Arches National Park, Utah; 19) Glen Canyon National Recreation Area, Arizona–Utah; 20) Grand Canyon National Park, Arizona; 21) Wupatki National Monument, Arizona; 22) Colorado National Monument, Colorado; 23) Florissant Fossil Beds National Monument, Colorado; 24) Great Sand Dunes National Park and Preserve, Colorado; 25) Bent's Old Fort National Historic Site, Colorado; 26) Salinas Pueblo Missions National Monument, New Mexico; 27) White Sands National Monument, New Mexico; 28) Lake Meredith National Recreation Area, Texas; 29) Big Bend National Park, Texas; 30) Amistad National Recreation Area, Texas; 31) Waco Mammoth National Monument, Texas; 32) Padre Island National Seashore, Texas; 33) Big Thicket National Preserve, Texas; 34) Buffalo National River, Arkansas; 35) Vicksburg National Military Park, Louisiana–Mississippi; 36) Niobrara National Scenic River, Nebraska; 37) Mississippi National River and Recreation Area, Minnesota; 38) Mammoth Cave National Park, Kentucky; 39) Potomac Heritage National Scenic Trail, multiple states; 40) Valley Forge National Historical Park, Pennsylvania; 41) New Jersey Pinelands National Reserve (affiliated), New Jersey; 42) Fort McHenry National Monument and Historic Shrine, Maryland; 43) Colonial National Historical Park, Virginia.

Sunday, January 15, 2017

Hyoliths II: The Hyolithening

Sorry, but I don't seem to have a better picture of local hyoliths, unless the things mentioned in this post or this post are hyoliths.

This week, the big paleontological news had nothing to do with dinosaurs, or mammals, or anything with bones at all for that matter. Instead, hyoliths got to be the subject of dozens of news articles, for the happy reason that their relationships are no longer quite so enigmatic. Undergrad Joseph Moysiuk of the University of Toronto and colleagues have presented research on the little guys showing that they were equipped with a tentacle-laden feeding apparatus, making them next cousins to...

[drum roll]

Sunday, January 8, 2017

Crystal Ball for 2017

Making predictions about paleontology is kind of awkward, at least if your predictions are based on what is published. Because there's usually five to ten years between a discovery and its publication, there's often a sense of what is out there, just not when it will appear. After all, we've got abstracts, press releases, photos on social media, etc... But what the hey? We're just having fun (hopefully). Lots of links to names are included in case you're mostly here for the Ordovician and aren't familiar with the lingo. Below are my predictions for dinosaur paleontology in the year 2017, after the photo of actual dinosaurs taken at much expense and personal risk via a secret and unfortunately now-lost technology.

Actual photo from the late Campanian of Canada. Things were surprisingly geometric then. Note that dinosaurs in their natural environment kind of hang around as if they are on coffee break, instead of constantly being on murderous rampages.