Afton graptolites revisited

There are two great lost fossil sites in the Twin Cities area. (The Brickyards don't count; they're not lost, they just aren't open to collection.) One is the Johnson Street Quarry, where workers cut into a bed in the Hidden Falls Member of the Platteville Formation that had unusually abundant echinoderms. As described in Sloan et al. 1987: 200, "Sardeson mined out a spot in this unit in the old Johnson Street Quarry in Minneapolis (now filled with garbage, and covered with Interstate 35) that produced about 20 specimens of the starfish Protopalaeaster narrawayi, several specimens of the crinoid Cremacrinus arctus (Fig. 16.2), edrioasteroids, cystoids, brachiopods, bryozoans, molluscs, and graptolites." This is slightly out of date; instead of a dump, there's now a Quarry Shopping Center with a Cub Foods, Home Depot, and Target, although even with all those options you can't get an edrioasteroid there anymore. Regardless of the exact character of the overburden, it seems unlikely that anyone will be doing any paleontological follow-up there anytime soon. The other locality is the Afton graptolite locality in the St. Lawrence Formation. We already had a post on why this locality was important; what I'm curious about is where exactly it was. A locality, even if "lost", had to have been *somewhere*, and apart from the scientific and historic interest, there very well could be similar fossils in rocks nearby. Indeed, Hughes and Hesselbo (1997) reported graptolites in the lowest strata of the St. Lawrence Formation in their Afton section, where collection may have postdated the road work that destroyed the classic location. For some reason, despite its “classic” nature, nobody ever saw fit to just put a pin on the map. What clues do we have?

More odds and ends

At the moment I'm preparing the grand annual update to The Compact Thescelosaurus. If you've been following along over the past couple of years, it doesn't take being Sherlock Holmes to guess what it will be. Actually, it doesn't even take being 1940s Radio Program Watson to guess, but do act surprised. In completely unrelated news, there's a taxon published this week I recommend you see: the little croc Thikarisuchus xenodentes. (What, you were expecting the theropod?) T. xenodentes, from the Cenomanian-age Blackleaf Formation of Montana, had a sharply triangular skull in top view and strongly differentiated teeth, among them the expected bitey teeth at the very front and long, low, narrow teeth at the back. This small croc may have had a taste for plants, or perhaps sliced up insects.

Something we love around here at Equatorial Minnesota is historical content about Minnesota geology. You may be familiar with the Minnesota Geological Survey's publication archive. It turns out that there are a bunch of MGS field notebooks scanned and available via the University of Minnesota libraries. You can find notebooks there from paleontologists such as Frederick Sardeson, Robert Sloan, and Clinton R. Stauffer, all of whom curiously have last names starting with "S". (Also interesting: Sardeson's field notebooks all have the left-hand pages filled out, but right-hand pages are much less frequently used. Was Sardeson a lefty?) There are also materials from the Department of Earth and Environmental Science.

Do you prefer to see your geology in the field? I came across a nice section of the St. Peter through Platteville under the I-94 bridge, on the east bank of the Mississippi. I'd been there years before but don't remember being so impressed with it. Maybe it wasn't as well-exposed then, or maybe I just wasn't experienced enough to appreciate it. The Platteville interval at the top was definitely exposed, but maybe this lower exposure is the result of more recent erosion or something. It definitely bears further photography and investigation, as it has a great view of the Glenwood.

The important part looks like this.

And here's what it looks like if I annotate all over it. I'm not entirely confident with the thickness of the Hidden Falls Member; for some reason the Mifflin is really grungy here. The Glenwood bits are open to interpretation (the Nokomis gets "Glenwood/St. Peter" because it's technically in the Glenwood but can't be distinguished from the St. Peter in well logs or gamma logs). The Tonti Member makes up most of the St. Peter Sandstone, if you're curious. There may be some Carimona at the very top. 

Oh yeah, also saw Bridal Veil Falls nearby, which has, y'know, seen better days, but is still running, after a fashion.

Or maybe you'd like some historical trivia? One of the things I wanted to find more about for the Mammoth Cave National Park paleo inventory was whatever became of the type specimen of Lithodrumus veryi, a Mississippian coral possibly collected from the park. It was described in 1904 by George Greene and the specimen has been lost to science since at least 1944. Greene's collection went first to the American Museum of Natural History and then to the National Museum of Natural History, but Lithodrumus veryi apparently went missing, as Easton (1944) couldn't find it at the AMNH. Just a few days ago I was looking up images of tabulate corals when I came upon a post at Louisville Fossils and Beyond that stated one cabinet had not been sold, and its contents were eventually going to the Indiana State Museum. Hope springs eternal! I've sent a message to the Indiana State Museum to see if perhaps L. veryi's type is there.

It's supposed to look like this (Greene 1904: Plate 49). Have you seen it, by any chance?

So that's what's going on around here. (Oh, that and some unusually intense bot "readership", or the whole of Hong Kong has suddenly discovered a passionate interest in the Ordovician fossils of Minnesota and Elliot Formation prosauropods. Maybe I'm cynical.) Tune in for the next post!

References

Allen, H. J., E. W. Wilberg, A. H. Turner, and D. J. Varricchio. 2025. A new, diminutive, heterodont neosuchian from the Vaughn Member of the Blackleaf Formation (Cenomanian), southwest Montana, and implications for the paleoecology of heterodont neosuchians. Journal of Vertebrate Paleontology e2542185. doi: https://doi.org/10.1080/02724634.2025.2542185

Easton, W. M. 1944. Revision of Campophyllum in North America. Journal of Paleontology 18(2): 119–132.

Greene, G. K. 1904. Contribution to Indiana palæontology 1(17): 168–175.

Whatever Happened to Euskelosaurus?

In principle, any dinosaur name considered dubious or a synonym can be brought back into use unless it is an objective junior synonym (based on the same specimen as a previous name) or suppressed by the International Commission on Zoological Nomenclature. In practice, some names are much more likely than others to rise out of the mire. For example, when was the last time you thought about Polyonax? (Is this the first time you've ever had occasion to think about Polyonax?) Then there are historical names based on questionable material that once were widely used but have now fallen completely out of favor. Think Monoclonius, Palaeoscincus, or Trachodon, long-time favorites that have staggered into obsolescence and cheap dinosaur toys.

Prosauropod rehab

I once wrote that "When you get interested in something, what's already there when you arrive will seem like it has always been there, and everything that comes along later will always seem a little new to you, even if it has been decades." Taxonomic fashion is one of those things. When I got into dinosaurs in the mid-1980s, prosauropods had shrunk to something like a half-dozen well-regarded genera plus some dross and a few names that were too new for someone to have gotten around to sinking. One of the survivors was always Ammosaurus, which somehow parlayed a few pelvic differences from Anchisaurus into family-level separation (Ammosaurus the plateosaurid, Anchisaurus the anchisaurid). Meanwhile, all of Africa's prosauropod diversity was being crammed, with varying degrees of success, into Euskelosaurus, Massospondylus, these things called "roccosaurids", and Aristosaurus. (Aristosaurus? You had to be there.) Since I had no personal memory of the work that had gone on in years before, and at five years old wasn't really pouring through the primary literature, it seemed like things had always been that way. This is not the case, though. The vast majority of this synonymization had taken place in the previous 10–15 years and was the work of just a few authors. What had come before that?

Well, obviously, what had come before that were the decades of describing and naming scads of prosauropods; otherwise, there wouldn't have been anything to synonymize. It seems like people loved to name them and then forget about them. The history of their research is littered with misconceptions, some of which seem blindingly obvious in hindsight (big predatory prosauropods? You sure you're not just looking at shed crowns from carnivorous animals?). It's a matter of lack of respect and interest: If dinosaurs were a sideshow to the evolution of important things (i.e., mammals), prosauropods were a sideshow to the sideshow, a couple of card tables featuring a guy with a big unibrow and someone doing "pull my finger" jokes.

Skip ahead a few decades. Some of my readers will have never heard of Aristosaurus (well, okay, nobody living has heard of Aristosaurus except me and maybe 10 other people who have been sworn to secrecy, and now I've lost my membership in the group for a cheap gag) and know only of Euskelosaurus as this thing that nobody talks about except to badmouth in the "Background" section of papers. You wouldn't remember the heady days of the '00s, when that genus collapsed under the weight of its synonyms. Instead, it will have always been a nomen dubium to you, and if it somehow returned (stranger things have happened), it wouldn't be a resumption of your interrupted Euskelosaurus service but something new. (Why, yes, I do have a sense I'm getting older. The only thing that saved me from being older than all MLB players this year was four games and 3 2/3rds innings from Rich Hill.)

Anyway, I've long had a soft spot for prosauropods. They're never been supremely popular and had the poor marketing insight to go extinct before they could be menaced by particularly charismatic theropods, but they have a subtle charm, like small bipedal ornithischians. Over the past year or so, there's been a series of papers providing redescriptions and historical analyses of some of the most venerable genera and species of prosauropods, including comments on some of those 1970s–1980s synonymizations. They include Barrett and Chapelle (2024) on Massospondylus, Barrett and Choiniere (2024) on Melanorosaurus, and Regalado Fernández et al. (2023) and Schaeffer (2024) on Plateosaurus.

Massospondylus

Another instance of perception not matching up with chronology: one of the things that comes out of Barrett and Chapelle (2024) was that before the 1970s, Massospondylus was kind of a dog of a taxon. It achieved its present exalted status mostly by getting there first and being less of a dog than the other choices. If Richard Owen had decided to lead with Leptospondylus or Pachyspondylus in 1854 instead of Massospondylus, it wouldn't have had that first point in its favor, and then where would we be? When a name was needed to absorb the mid-sized prosauropods of the Early Jurassic of southern Africa, M. carinatus was there waiting. Some of the new material was good enough to support a name, and our conception of Massospondylus carinatus drifted from the varied bones named by Owen to that material, which eventually supplied a neotype (a type or name-bearing specimen selected after a species was named, to replace a type that was lost or not specified). The original material was no longer available to query, having been destroyed in World War II, but casts and line drawings of some of it remain, and Barrett and Chapelle (2024) provided redescriptions of as much as they could. In the end, it's just as well that the species is now represented by a neotype, because that original material is not diagnostic beyond the level of Massospondylidae at best. The drift of the conception of Massospondylus, plus the uncritical assignment of a lot of material since the 1970s, leaves the possibility of surprises once "Massospondylus" specimens are thoroughly examined. This also applies to Melanorosaurus and Plateosaurus. (Granted, I'm not convinced that every new genus and species will stand the test of time, but that's for another time, when the pendulum eventually swings back to consolidation.)

Massospondylus as a flowchart. Figure 4 of Barrett and Chapelle (2024). CC BY 4.0.

Melanorosaurus

Proposed synonymizations don't always pan out, of course (one reason not to go overboard committing to the conclusions of New Paper Of The Week). The proposed sinking of Lufengosaurus and Yunnanosaurus into Massospondylus at the height of prosauropod consolidation did not attract much support, and the proposed sinking of Melanorosaurus into Euskelosaurus fared only marginally better. Although it escaped that fate, Melanorosaurus has never seemed to get much respect. It's almost a reflex for authors to mention its questionable type material, as if apologizing for trotting it out. Barrett and Choiniere (2024) went back to the original syntype series (a group of specimens used to bear a name) to see what could be salvaged.

M. readi, like many a species, was based on your standard pile o' bones of unclear association. Barrett and Choiniere (2024) regarded a subset, including several partial or complete vertebrae, an ulna, a radius, an ilium, a partial pubis, two tibiae, a fibula, and parts of four metatarsals, as representing one skeleton that they designated a lectotype (a name-bearing specimen selected from a syntype series). Furthermore, they were able to find several diagnostic features. It's not the prettiest type, but it *is* useable. The authors compared the lectotype to several other specimens frequently used as Melanorosaurus exemplars in the literature. Unfortunately, this part doesn't go quite so well for M. readi; NMQR 3314, one of the more important specimens (including a skull), is excluded on both anatomic and stratigraphic grounds. Another specimen, NMQR 1551, is considered consistent with M. readi but an assignment is not confirmed. (I personally hope it is, because I don't want an excuse for someone to try to bring back "Roccosaurus" as a name.) The upshot is M. readi is valid but not particularly helpful at the moment, pending reclamation of more complete material.

Plateosaurus

If Massospondylus is what you get when specimen assignment goes to the last species standing, Plateosaurus is what happens when people care too much. For sheer mind-numbing taxonomic complexity in the world of dinosaurs, it's hard to beat the adventures of Upper Triassic European prosauropods. An extensive historical review can be found in Regalado Fernández et al. (2023), along with detailed reports on many of the significant specimens involved in the story. One of the things I find useful is rather than synonymize the many lesser lights with a species of Plateosaurus, the authors treat them as dubious species. Why is this useful? Keeping them separate helps to keep the concept of the host species from drifting. It's not as if there's some prize for having the tidiest faunal list, after all; specimens should only be assigned to the level of confidence.

Stratigraphic distribution of German Plateosaurus and friends. I could quote every figure in this article, but then I might as well reproduce the whole thing. Figure 2 in Regalado Fernández et al. (2023) CC BY 4.0.

Coming at Plateosaurus from a different angle, Schaeffer (2024) redescribed the holotype (singular name-bearing specimen) of P. trossingensis, which became the type species of Plateosaurus a few years back (another long story). This gets right at the heart of the taxonomic drift: you have to establish your basis of comparison before you can compare anything to it. Continuing with this, Schaeffer ran a phylogenetic analysis of sauropodomorphs with Plateosaurus trossingensis based just on the holotype. Fortunately, the species behaved predictably in terms of general location and neighbors.

References

Barrett, P. M., and K. E. J. Chapelle. 2024. A brief history of Massospondylus: its discovery, historical taxonomy and redescription of the original syntype series. Palaeontologia africana 58: 97–131.

Barrett, P. M., and J. N. Choiniere. 2024. Melanorosaurus readi Haughton, 1924 (Dinosauria, Sauropodomorpha) from the Late Triassic of South Africa: osteology and designation of a lectotype. Journal of Vertebrate Paleontology 44(1): e2337802. doi: https://doi.org/10.1080/02724634.2024.2337802

Regalado Fernández, O. R., H. Stöhr, B. Kästle, and I. Werneburg. 2023. Diversity and taxonomy of the Late Triassic sauropodomorphs (Saurischia, Sauropodomorpha) stored in the Palaeontological Collection of Tübingen, Germany, historically referred to Plateosaurus. European Journal of Taxonomy 913(1): 1–88. doi: https://doi.org/10.5852/ejt.2023.913.2375

Schaeffer, J. 2024. Osteological redescription of the holotype of Plateosaurus trossingensis (Dinosauria: Sauropodomorpha) from the Upper Triassic of SW Germany and its phylogenetic implications. Journal of Systematic Palaeontology 22(1): 2335387. doi: https://doi.org/10.1080/14772019.2024.2335387

Secrets of "Secrets Of The Dinosaur Mummy", or: How I Got An IMDb Entry

A few days back I did something I hadn't done since 2008: I watched "Secrets of the Dinosaur Mummy". This was mostly because I had a friend over and wanted to show her what the Leonardo thing was all about, along with my minor claim to small-screen fame. Obviously going that road brought out the memories, so I thought maybe it was time to have a look back. Getting the "Truth in Advertising" out of the way up-front: I don't actually have a lot of secrets about "Secrets of the Dinosaur Mummy", but I do know a title when I see one!

It turned out to be unexpectedly difficult to get a good photo of the cover, being moderately glossy and dark, but you get the idea. One of these two blurbs is good for a chuckle, given the prominence of the speaker in the documentary.

Campus fossils of the University of Michigan

For the previous week I was attending the North American Paleontological Convention, held this year in Ann Arbor, Michigan by the University of Michigan. While walking and wandering on the campus, it became clear that many of the buildings include fossiliferous rock, so I began to look for interesting examples.

Like that. That's interesting. (coin in all examples with coins is a US quarter)

Fossil Collections of the Ancestral Puebloans

Although the ancient biological origin of fossils has only been widely appreciated in the past couple hundred years, people have collected fossils for various reasons for millennia. One of my favorite instances is recorded by Roman biographer Suetonius, who noted that Augustus had a collection of bones of "sea and land monsters" at Capri. (By the way, if you're also a sucker for ancient history as written by ancient historians, "The Twelve Caesars" is a great book.)

One of the things I've come across working with National Park Service paleontology is that the Ancestral Puebloans, represented by numerous locations in the NPS, had a notable interest in fossils. This is something that took a while for me to realize because most of the evidence is in the archeological literature and as a paleontologist, I didn't know to look in it. On the flip side, the archeologists generally didn't make a big deal of finding run-of-the-mill fossils among the artifacts at their sites; for them, fossils were just one class of objects among many. I haven't made an exhaustive survey, but a couple of sites stand out.

Pecos Pueblo is the namesake feature of the complex Pecos National Historical Park. The pueblo was excavated between 1915 and 1925 by Alfred Vincent Kidder of the Robert S. Peabody Museum of Archaeology (Phillips Academy, Andover, Massachusetts). Kidder (1932) reported finding "many hundreds" of fossils at Pecos Pueblo. They were predominantly marine fossils from "the limestone formations underlying the red sandstones of the valley", which appears to correspond to the Pennsylvanian-age Alamitos Formation of the Madera Group. Among these were corals, brachiopods ("bivalves" of the photo caption), snails, and crinoids. Not all were marine; among them was a partial rhino tooth, and there were also many pieces of petrified wood, including colorful Chinle wood and brown or gray wood typical of the area southwest of Santa Fe, possibly selected for its unusual cleavage and the "clear, resonant tone which it gives when tapped". Kidder observed that the majority of the fossils were found in rubbish and suggested they were collected as curios, but I have to wonder. It takes some effort to collect hundreds of fossils (although admittedly Pecos Pueblo was inhabited for a long time).

Pecos Pueblo is hardly a patch on Pueblo Bonito of Chaco Culture National Historical Park, though. Pepper (1920) documented fossils in 18 rooms, not counting artifacts made of petrified wood. Most had just a few, but Room 12 is something else. Room 12 has a floor area less than 10 square meters (108 square feet; a bit less than 3.7 by 2.7 m or 12 ft by 9 ft), and when excavated contained a 1.5 m (5 ft) thick layer including the following:

• 1,000+ small fossil shells
• 300 fragments of crinoid stems
• 140+ water-worn pebbles
• 125+ chalcedony concretions
• 125+ fragments of contemporary Pacific shells
• 50 to 75 specimens of crystals or other rocks and minerals of beauty or interesting form

This is the largest intentional accumulation of fossils predating the rise of museums that I've come across. Furthermore, unlike Pecos Pueblo, a significant chunk of the paleontological collection could not have been collected more or less "in the backyard". Judd (1954) provided taxonomic identifications of some of the fossils from a re-excavation. Chaco Canyon is over Campanian (Late Cretaceous) bedrock. The taxa identified from Room 12 include several Pennsylvanian-age brachiopod species known from central New Mexico, a Cenomanian ammonite (Metoicoceras whitei) with its nearest occurrences in the Black Mesa area of Arizona, and a snail (Gyrodes compressa/Euspira compressa) known from Upper Cretaceous rocks of the Pacific coast of California. This is a gathering of fossils that took some effort.

What exactly were the inhabitants of Pueblo Bonito doing with 1,300+ fossils? Agostini and Notterpek (2020) suggest that the fossil shells, together with the water-worn pebbles and concretions, were symbolic of water and a "past watery world". The canyon itself would also be symbolic of the action of water. It's an interesting idea, although again I do marvel at the sheer number of fossils. The scientific romantic in me wonders if there was someone there who just found fossils and minerals interesting, maybe even had them arranged in some pleasing setup (even sorted by morphology), and perhaps cultivated the collection of rare and unfamiliar objects. Or, maybe concentrating all of those fossils in one small place amplified their power. Or, maybe it was something like a museum, or at least a place to display and contemplate these objects. But what do I know?

References

Agostini, M. R., and I. Notterpek. 2020. Cosmological expressions and medicine stones in the Ancestral Pueblo world. KIVA 86:(4):4030–427. doi: https://doi.org/10.1080/00231940.2020.1832406.

Judd, N. M. 1954. The material culture of Pueblo Bonito. Smithsonian Miscellaneous Collections 124.

Kidder, A. V. 1932. The artifacts of Pecos. Yale University Press, New Haven, Connecticut.

Pepper, G. H. 1920. Pueblo Bonito [large file]. Anthropological Papers of the American Museum of Natural History 27.

G. Suetonius Tranquillus. 121. The twelve Caesars. Penguin Books, London, England. 1989 reprint of 1957 translation by Robert Graves.

On the concept of "100 Dinosaurs from A to Z"

Back in the 1980s, there were books aimed at the kid market that promised 100 (or 101) alphabetical dinosaurs. This was about the last time in dinosaurological history when a book with that premise could still boast a fairly comprehensive selection of reasonably well-known dinosaurs. To be honest, it's a little unclear in hindsight why books with 100 dinosaurs would be compelling when there were competing books on the market that gave the reader more dinosaurs and were not significantly more difficult reading. Maybe they were seen as more kid-friendly, but then again, someone who's up for "100 Dinosaurs" is probably going to age out of it and go for "A Field Guide To Dinosaurs" pretty quickly. The market seemed to agree, because the books turned into just "Dinosaurs A-Z" by the end of the decade and then disappeared.

Most of them were not actually complete alphabets, simply because the dinosaur alphabet wasn't completed until 1983 (Quaesitosaurus and Xiaosaurus), and for several other letters, the choices were pretty dismal. F would always be Fabrosaurus, which may well have helped it hang around after taxonomic obsolescence by lodging in the brains of impressionable children. (Otherwise there was Fulgurotherium, but it was poorly known, space was limited, and Muttaburrasaurus and perhaps Rhoetosaurus were already there to represent Australia.) U would be "Ultrasaurus", because it was huge and in the news and the only other option was Unquillosaurus. J? It's a choice between the two immortals Jaxartosaurus or Jubbulpuria, or just skipping it. (In related news, I've had a soft spot for Jubbulpuria for decades. Us "J"s have to stick together!)

With a minimal knowledge of 1980s dinosaurs, it's easy enough to figure out most of the genera that would be in these books.

• First you have the superstars: Tyrannosaurus, Triceratops, Stegosaurus, Apatosaurus (with obligatory comments about Brontosaurus). Today, that inner ring would include Spinosaurus and Velociraptor (even if Deinonychus did the heavy lifting), and Brontosaurus would swap for Apatosaurus.
  
• Then there's the B-listers, names like Allosaurus, Parasaurolophus, Styracosaurus, Brachiosaurus, and Iguanodon, and lots of entries from the Morrison and Late Cretaceous of North America.
• Then you descend into a grab-bag of C-listers, geographic and stratigraphic tokens and oddities, and flavors-of-the-month, some of which would go on to better things, while others didn't. (Yaverlandia! "Ultrasaurus"!)
• Finally, there's Geranosaurus and Altispinax. (Altispinax never had it so good as it did in the 1980s.)
  

Today, with more than 1600 formally described species of non-avian dinosaur that a reasonable person (i.e., me) would recognize (with some sleeping dubious dogs being left to lie to avoid inconvenient issues of priority), promising "100 dinosaurs" is not impressive. At the moment, one could write "100 dinosaur" books just on specific countries. Argentina, China, Mongolia, the United Kingdom, and the United States of America all qualify (granted, the UK edition would have a distinctly scrappy and Victorian flavor), with Canada almost there. In fact, with China and the US both well over 300 species, "100 dinosaur" books for them would be omitting more than 2 out of 3 species. Surprisingly, complete alphabets of dinosaurs from these prolific countries are not possible at this time; Argentina (missing "Y") and China (missing "U") get the closest, with the U.S. a distant third with no "Q", "W", or "X".

It is also possible to have entire "100" books on certain groups. Maniraptors? No sweat, at just over 200 (which gives some wiggle room for reclassification of entire lineages). Old-timey prosauropods? Yep, they just make it. Titanosaurs? Room to spare (as we observed in great detail). Ankylosaurs just make it, too (you can throw in stegosaurs for more thyreophoran charm and bump some of the underachievers). Ceratopsians cross easily, and while hadrosaurids by themselves don't quite make it, going down to Hadrosauromorpha to pick up traditional basal hadrosaurs also crosses the threshold. Complete alphabets are still a problem, though. (You can do it with titanosaurs if you make Wintonotitan an honorary member.) Why someone should *want* to write a book on 100 dinosaurs of a country or a specific group, I'm not sure (if you were going to go to the trouble, you might as well cover *all* of them and not just an arbitrary number), but someone certainly *could*.

When I started drafting this post, I thought about coming up with my own list of 100 dinosaurs, for the fun of it. Then I realized I would basically pick 100 dinosaurs I remembered as important from the 1980s. While classics are classics for a reason, it isn't any fun to come up with the same old list that any of us could have picked. Nor was the idea of consciously selecting some kind of quota (geographic, stratigraphic, taxonomic, year of description, etc.). So, I decided to leave it up to fate. I copied the genera and species from The Compact Thescelosaurus, then took some pity and eliminated every nomen dubium, which removed 315 entries. (Before I did this, I tried it once and got all three entries for Cionodon. Yay?) The remaining 1,313 were run through the Google Sheets random sort function and the first 100+ entries were grabbed to produce the following lightly curated list (the entries were at the species level but the books always worked at the genus level, so I scratched multiple entries from the same genera). If you don't like Dravidosaurus or would rather have 101, the genus on deck is Tyrannotitan. If both conditions apply, then Rugocaudia is up next.

Behold, 100 Random Dinosaurs From A To Z:

Acristavus	Dracovenator	Leptorhynchos	Scutellosaurus
Acrotholus	Dravidosaurus	Lirainosaurus	Shidaisaurus
Adamantisaurus	Ekrixinatosaurus	Lufengosaurus	Similicaudipteyx
Adasaurus	Eomamenchisaurus	"Mamenchisaurus" sinocanadorum	Soriatitan
Adelolophus	Epachthosaurus	Mendozasaurus	Spinosaurus
Afrovenator	Eucnemesaurus	Miragaia	Stenopelix
Albertonykus	Euhelopus	Monolophosaurus	"Syntarsus" kayentakatae
Alioramus	Euoplocephalus	Nambalia	Tendaguria
Altirhinus	Europasaurus	Nanosaurus	Timimus
Anhuilong	Ferganocephale	Nanuqsaurus	Torosaurus
Antetonitrus	Graciliceratops	Neuquenraptor	Torvosaurus
Aviatyrannis	Hesperornithoides	Nigersaurus	Tototlmimus
Bahariasaurus	Hypselospinus	Notatesseraeraptor	Tsintaosaurus
Beipiaognathus	Hypsilophodon	Ouranosaurus	Unenlagia
Caenagnathasia	Iguanacolossus	Patagonykus	Utahceratops
Camarillasaurus	Incisivosaurus	Patagosaurus	Valdosaurus
Camposaurus	Isanosaurus	Piveteausaurus	Vouivria
Camptosaurus	Iyuku	Plateosaurus	Wuerhosaurus
Carcharodontosaurus	Jeyawati	Plesiohadros	Xenoceratops
Ceratosaurus	Jingshanosaurus	Polacanthus	Xiaosaurus
Chaoyangsaurus	Juravenator	Regaliceratops	Yandusaurus
Chirostenotes	Kaatedocus	Ruehleia	Yangchuanosaurus
Citipes	Klamelisaurus	Saichania	Yehuecauhceratops
Dongbeititan	Leaellynasaura	Saltriovenator	Yixianosaurus
Dracoraptor	Leptoceratops	Sanxiasaurus	Zhongjianosaurus

You know what? I feel pretty good about this list. It's got an interesting spread in time, space, lineage, and fame. It gets 25 out of 26 letters, too (no Q, which didn't show up until 257 with the much-beloved Qinlingosaurus, but that's randomness for you).

Historical miscellany, including O.P. Hay, Whitesburg fossils, and the "Scientific Swindler"

A selection of brief historical items for your approval:

If you're like me and have an interest in Pleistocene megafauna, you've probably spent some time tooling around Neotoma and NeoMap (which unfortunately doesn't work anymore), as well as the Paleobiology Database. (In fact, it's kind of necessary to use multiple databases because they don't all have the same information.) Compiling datasets like these can be a thankless job. The actual business of making one is time-consuming and requires access to a vast array of scholarly (and less-scholarly) resources. To make it more efficient, you can bring in a crowd to contribute smaller parts, with the obvious trade-off that quality control is harder to maintain (and participants may disagree strongly about things like taxonomy). Synthesizing material doesn't get as much respect as producing new information. It takes a certain kind of personality to compile these things (I ain't about to name any characteristics, because I'd just be pointing in the mirror). You also want to be very, very sure you get it right, because sometimes people just accept the compendium and forget to check the original sources.

There are many state-level compendia of Pleistocene finds for the US, and at least one excellent regional resource (for the southwestern US and northwestern Mexico). They don't exist for every state, though, and unfortunately many are in the neighborhood of a century old. (If anyone wants a reference for a specific state, I can see what I can do.) By far the most monumental of these monuments to industry are the three volumes produced by Oliver Perry Hay in the 1920s, the "Vertebrated Animals of North America" series. Hay was no stranger to compiling information, with two bibliographies on North American fossil vertebrates under his belt. For people used to the Internet, it takes a moment to realize the staggering amount of work that must have gone into these books, which cover the entire continental US and Canada from the beginning of scientific documentation of fossils to his own day. Even granting that the field was smaller and there were fewer publications, the number of references he must have seen must have been immense (to say nothing of the work of tracking them down). That there are occasional errors and omissions is not the wonder; the wonder is that these books exist at all. I've included citations to several of his volumes at the end; all are freely available for download at the moment except the third volume of the "Vertebrated Animals" series, but even this one can be read online.

I've referred to Hay's works many times in my own work; on this occasion he came to mind because I happened upon a seemingly forgotten Pleistocene fauna from northeastern Tennessee that he described with five other Pleistocene collections (Hay 1920). The Smithsonian had received a collection made by USGS geologist Ira Sayles in 1885 from "one mile north of Whitesburg, Hamblen Co., Tenn." Matrix with the bones indicated that the site had once been a cave, now eroded. Hay recognized twenty species from the fauna, eight of which were extinct and three of which were new species (turtle Testudo munda, tapir Tapirus tennesseae, and deer Sangamona fugitiva; none of them is considered valid anymore, which tends to happen with supposed new Pleistocene species in North America, but Sangamona fugitiva is a nice name). What gets me is that there's never been any real follow-up outside of Hay's own 1923 compendium of Pleistocene sites. The actual location is still unknown to this day, if it could even be rediscovered. That's one of the things that I love about these compilations and databases: there's a story behind every site, even if it's not known in detail.

Finally, I wanted to mention a historical story I came across this spring while working on another topic. It is a story of fraud in science, but not the usual "unscrupulous scientist scoops another worker or commits a nefarious action against a graduate student." It goes like this: from the mid-1880s to the early 1890s there was a man operating in the Midwest and Northeast who would use false pretenses to swindle scientific books, equipment, and fossils from unsuspecting geologists, to sell them. Among his methods were pretending to be deaf-mute and stealing the identities of other geologists, including such luminaries as Leo Lesqueroux and Charles Walcott. His trail can be followed by a series of letters in scientific journals reporting encounters and giving warnings, but he was able to operate for years. The icing on the cake is that he was actually a competent paleontologist, as attested by several of the victims. It's a fascinating story worthy of a journal article, and fortunately we have what amounts to one in a lengthy blog post, so if you're looking for something to read, it's well worth the time!

References

Hay, O. P. 1902. Bibliography and catalogue of the vertebrata of North America. U.S. Geological Survey, Washington, D.C. Bulletin 179.

Hay, O. P. 1908. The fossil turtles of North America. Carnegie Institution of Washington Publication 75.

Hay, O. P. 1914. The Pleistocene mammals of Iowa. Iowa Geological Survey Annual Report 23(1):1–662.

Hay, O. P. 1920. Descriptions of some Pleistocene vertebrates found in the United States. Proceedings of the United States National Museum 58:83–146.

Hay, O. P. 1923. The Pleistocene of North America and its vertebrated animals from the states east of the Mississippi River and from the Canadian provinces east of longitude 95°. Carnegie Institution of Washington Publication 322.

Hay, O. P. 1924. The Pleistocene of the middle region of North America and its vertebrated animals. Carnegie Institute of Washington Publication 322A.

Hay, O. P. 1927. The Pleistocene of the western region of North America and its vertebrated animals. Carnegie Institute of Washington Publication 322B.

Hay, O. P. 1929. Second bibliography and catalogue of the fossil vertebrata of North America, volumes I and II. Carnegie Institution of Washington Publication 390.

Musings on Hanyusuchus

Every year a handful of new croc taxa are described. If you're strictly in this business for the dinosaurs, you ought to see what the croc side of Archosauria has been up to from time to time; they were quite versatile in palmier days. Even though they aren't quite as diversified as they used to be, it turns out they had hitherto-unsuspected tricks up their sleeves even as recently as a few hundred years ago. This spring a new genus and species of gavialid was described from the Holocene of south China: Hanyusuchus sinensis. This is fascinating, for many reasons. The obvious is that here we have a species of [insert expletive of choice] 20-foot-long gavial that existed up to perhaps a few hundred years ago in full contact with one of the most thoroughly documented civilizations in history, and it was completely overlooked. It may not have gone extinct until the time of the Ming dynasty. This is something like discovering that bears in Greek and Roman mythology were actually Arctodus, only if Arctodus was the size of a pickup truck. China, of course, is noted for the extant Alligator sinensis, but although the Chinese alligator is many things, not even on its best days has it been a 20-foot-long gavial.

Figure 2(s) from Iijima et al. (2022). Depicted: Hanyusuchus sinensis (composite, scaled to holotype) and 1.8 m (5.9 ft) tall human. Not pictured: Alligator sinensis (to imagine, mentally scale the Hanyusuchus to be about the same size as the human). CC BY 4.0.

Another fascinating aspect is the namesake. Han Yu was a significant writer, philosopher, and politician of the Tang dynasty. At one point in his life, he got in trouble at court and was packed off to Chaozhou in Guangdong, southeastern China to serve as prefect. In this capacity, he issued a proclamation in 819 concerning the crocodilian population. This in itself is not remarkable, except for the audience: he issued it to the crocodiles themselves. A translation of the statement can be found here (well worth a read). The icing on the cake is that the crocodiles reportedly did as instructed and departed, although we can presume that if they *did* indeed vanish from the area, strong hands wielding metal implements (like the Bronze Age weapons that left marks on some specimens) were more important in enforcing the departure. The reader may suppose that Han Yu's action was just a quaint old-time delusion; after all, there is a long history of animals being prosecuted for crimes. However, as the author of the translation notes drily, "Tang prefects did not habitually make formal verbal addresses to the local fauna" (footnote 7, p. 60). One wonders if perhaps Han Yu, who was noted for a sense of humor, had his tongue firmly in cheek.

There's also a melancholic existential aspect to the discussion. H. sinensis was part of the fabric of life in southern China for thousands of years. Descriptions of the species can be identified in historical sources, now that we know what to look for. Dynasties, cultural flowerings and renaissances, wars, conquerors, travelers like Marco Polo and Ibn Battuta, all came and went while 6-m gavials patrolled the southern rivers. They took livestock and killed people. They were apparently very noisy, probably the source of reportedly "thunder-like sounds in the night". Then they were driven into extinction and basically forgotten for hundreds of years.

References

Iijima M, Qiao Y, Lin W, Peng Y, Yoneda M, and Liu J. 2022. An intermediate crocodylian linking two extant gharials from the Bronze Age of China and its human-induced extinction. Proceedings of the Royal Society B: Biological Sciences 289:20220085. doi:10.1098/rspb.2022.0085.

A comment on the history of the venomous Iguanodon

There's a funny little piece of trivia attached to Iguanodon on the Internet, that once upon a time someone suggested that the famous thumb spikes were not merely wielded as pointed instruments of close-quarters defense, but may have also delivered venom. This tidbit is most readily found in the Iguanodon entry on Wikipedia, where up until recently the idea was described as coming from Tweedie (1977) and being refuted in Naish and Martill (2001) and a Dinosaur Mailing List post by Darren Naish based on the absence of any anatomical evidence (e.g., hollow spike, grooves, open tip). All in all, the whole thing just comes across like an example of an out-there Dinosaur Renaissance concept.

There is a catch, though. "Love in the Time of Chasmosaurs" recently covered Tweedie's book in two posts, but the venomous Iguanodon did not make an appearance, as documented in the comments. I vaguely remembered reading the same thing about Iguanodon back in the day, though, so I thought I'd have a look, and I already had another source in mind: "Dinosaur Mysteries", a pop-sci-type dinosaur book from 1987 (Elting and Goodman 1987). (Coincidentally enough, LITC covered this book almost nine years ago to the day in their old digs.)

Problem: while I used to have a copy of this book (in fact, I think I had two at one point, there being relatively few dinosaur books available for many relatives looking for birthday and Christmas presents in the late 1980s), I don't now. Solution: it just so happened that Internet Archive includes a copy in their surprisingly thorough dinosaur collection. I simply signed in and there I was. Right there in the Table of Contents was "The Case of the Poisoned Spike". On page 46 was this passage:

"But could the spikes have contained poison—the way a snake's fang's hold venom? One scientist thinks that poisoned thumbs might have been a good form of protection. That is a mystery still to be solved."

And there we have it: a reference to venomous Iguanodon. It has about as much substance as your typical daydream ("one scientist" would have Wiki editors reaching for their templates), but it exists. But what of Tweedie?

It turns out Tweedie does have something to say. On page 69, we read this:

"It [the thumb spike] is usually regarded as a defensive weapon but no one has explained how it could have been effective against the great claws and rending teeth of a large theropod. There are many things concerning dinosaurs that the fossil record can never tell us about. If these living animals were known to us only as fossils, who would be bold enough to suggest that the spur on the hind leg of the platypus or the spine on a sting-ray's tail were weapons charged with venom? Dinosaurs must have been very diversely adapted animals, and it is reasonable to suppose that most of the more obvious defensive devices seen among modern animals were evolved by them."

This is a fascinating piece of work. Nowhere in it does the author explicitly propose that Iguanodon had venomous thumb spikes. Read as a whole, though, the effect is that the reader is drawn to that conclusion. To me, someone involved in the writing of this book really, really wanted to include a venomous Iguanodon but either couldn't pull the trigger on stating it plainly or was argued (or edited) out of it. Did Elting and/or Goodman read this passage and come to the unstated conclusion, making Tweedie "one scientist"? Fittingly, Naish and Martill (2001) write that Tweedie "implied" this conclusion.

References

Elting, M., and A. Goodman. 1987. Dinosaur mysteries. Platt & Munk, New York, New York.

Naish, D., and D. M. Martill. 2001. Ornithopod dinosaurs. Pages 60–132 in D. M. Martill and D. Naish, editors. Dinosaurs of the Isle of Wight. The Palaeontological Association, London, United Kingdom. Field Guide to Fossils 10.

Tweedie, M. W. F. 1977. The world of the dinosaurs. Weidenfeld & Nicolson, London, United Kingdom.

Theory and Application of Hypsibema

The dance of splitting and lumping will go on as long as there are two people and something to classify. On the one hand are the creators of new names. Are they revealing the hidden biological diversity of the past and present, or are they necessary evils at best, scurrilous egotistical rogues who turn taxonomy into tacky monuments to their own questionable genius at worst? On the other hand are the lumpers. Are they providing clarity against confusing multiplicity, or are they cranky reactionary gatekeepers who secretly (or not-so-secretly) flatter themselves as lonely upright crusaders against disorder and incompetence? Well, fellas, you can make questionable decisions splitting or lumping!

Consider, for a moment, the case of Hypsibema:

Late in 1869, Edward Drinker Cope presented a group of bones from North Carolina to the Academy of Natural Sciences of Philadelphia. He proposed to name the assortment Hypsibema crassicauda. The description takes up a grand total of 112 words (no illustrations, of course) and is reprinted below in its entirety:

"He [Cope] exhibited a number of remains of fossil reptiles, from Sampson Co., North Carolina, of cretaceous age, which were intrusive in miocene beds. Among these were humerus, tibia, fibula, metatarsus, caudal vertebra, and perhaps cervical vertebrae and ungueal phalange of a Dinosaur, discovered together by Prof. W. C. Kerr, Director of the Geological Survey of North Carolina. The remains indicated a species having the same general form and size as the Hadrosaurus foulkei. The caudal vertebra was of very different form, and resembled more that of Hylaeosaurus, minus the diapophyses. This vertebra was elongate, depressed and angulate. The animal presented various other points distinguishing it from Hadrosaurus, and was named Hypsibema crassicauda."

Note that Cope had received them second-hand, with no other information about their association other than they were "together". He was young at this time, not yet 30 and just getting started in this dinosaur business, but this was just one example of a worrying tendency that would show up again in his career: despite all of his undoubted paleontological acumen, he never seemed to twig to the idea that perhaps collections of bones found in the same general area did not necessarily belong to the same species or even genus. (See also Monoclonius.)

Because H. crassicauda was thought to have hadrosaurian affinities, Lull and Wright (1942) naturally included it in "Hadrosaurian Dinosaurs of North America". By that point Cope's bounty had been reduced to a caudal vertebra, the distal end of a humerus, a tibial shaft, and a partial metatarsal II, catalogued as USNM 7189 (National Museum of Natural History, Washington, D.C.). Lull and Wright passed the following judgment: "The material is too meager and uncharacteristic to permit a real definition of the genus and species, and the form must therefore be considered a nomen nudum [as mentioned here, basically a nomen dubium as understood today]. It indicates, however, the presence in North Carolina of Cretaceous hadrosaurs of uncertain affinities." Well, hallelujah, and so forth; insert your own uproar as the mood strikes. (One slightly disconcerting note: Lull and Wright thought the caudal resembled the caudal of fellow North Carolina form Hadrosaurus tripos. Hadrosaurus tripos is now regarded as a Pliocene whale.)

In hindsight it is very easy to say that Cope shouldn't have bothered naming Hypsibema crassicauda. The material isn't great and there is no real evidence that any of the bones belong to the same thing. It can be counter-argued that he didn't know any better and was acting within the bounds of mid-19th century vertebrate paleontology, but it still is not his finest hour. (None of the surviving bones can even articulate, for crying out loud. Even if they'd been found in an area the size of a square foot they could still easily be a hydraulic concentration of random fauna, and here he is thinking they're the same thing after getting them second-hand at best?)

So much for the 19th century.

Elsewhere and elsewhen, in 1942 geologists of the Missouri Geological Survey were studying clay units in southeastern Missouri. One of them, Dan Stewart, came into contact with Lulu Chronister, who told him about bones found on the Chronister farm during the digging of a well. One thing led to another, and in early 1945 Stewart and Charles Gilmore (of Thescelosaurus and Alamosaurus fame around here) published a description of 13 caudal centra (neural arches apparently lost around the time of discovery) and two fragments, catalogued as USNM 16735. They used the bones as the basis of new sauropod Neosaurus missouriensis (Gilmore in Gilmore and Stewart 1945). If you've never heard of Neosaurus missouriensis, it's because Neosaurus turned out to be preoccupied, and Gilmore quickly substituted Parrosaurus (Gilmore 1945). Gilmore (in Gilmore and Stewart 1945:25) commented that "[t]he specimen on which the present paper is based consists only of caudal centra that in the ordinary course of events would be considered too meager for generic designation, but in view of the uniqueness of both its geographical and geological occurrence the name Neosaurus missouriensis is proposed for its reception."

Neither Hypsibema crassicauda nor Parrosaurus missouriensis garnered much attention over the next few decades. Then, in 1979 Donald Baird and Jack Horner published a review of Cretaceous North Carolina dinosaurs. Things did not go well for Hypsibema crassicauda at first; Baird and Horner determined that the type material was chimeric. They restricted the type to just the caudal vertebra, because Cope had based the species name ("thick-tailed") on it, and identified it as belonging to a sauropod. They then pulled the tibial and metatarsal fragments as hadrosaurian, and identified the "humerus" as the distal end of a tyrannosaurid femur. So far, this is just another case of the clinical dissection of an obscure questionable name.

Then, though, the authors brought out Parrosaurus missouriensis. Technically speaking, with a publication title of "Cretaceous dinosaurs of North Carolina" they could have ignored P. missouriensis and nobody would have felt shortchanged, but they opted to go the extra mile. In fact, they went farther than the extra mile, sinking Gilmore's species into Cope's species: "Now that Hypsibema has been freed of hadrosaurian encumbrances its genetic identity with Parrosaurus becomes obvious. Every morphological feature cited for the Missouri vertebrae can be matched in those from North Carolina. Indeed, the possibility of specific identity cannot be dismissed..."

The bit about sauropod (mis)identification is a topic for another time and place. For the moment, the critical piece is sinking one poorly known species into a different poorly known genus on the basis of exactly one piece of overlapping material: the caudal of H. crassicauda, with remnants of the neural arch (which you don't even get with P. missouriensis). Even if they are very similar, that's asking a lot out of dinosaurian caudal centra, which are not generally noted for having unusually high concentrations of apomorphies. Implicitly this classification is saying that the rest of the body of the two forms will not differ significantly, a bold statement all around. Whether or not you agree with the synonymization, I suspect you'd probably agree that it's not an ideal situation.

Because for many years there was little interest in the disposition of H. crassicauda and P. missouriensis (although missouriensis became the state dinosaur of Missouri during that time frame), the generic synonymization has persisted. Recent developments in Missouri bode fair to spur a reassessment, though.

[Note: despite the url for this entry, I did not write it in August 2018, I only started working on a post with a couple of the ideas and gave it a custom url because I didn't like the automatic version. (For that matter, the present entry owes much more to another and even older post idea.) Of course, I had long forgotten about the custom link when I dusted it off. Seeing as there's no critical reason to change it, I'll let it stay.]

References

Baird, D., and J. R. Horner. 1979. Cretaceous dinosaurs of North Carolina. Brimleyana: The Journal of the North Carolina State Museum of Natural History 2:1–28.

Cope, E. D. 1869. [Remarks on Hypsibema crassicauda and Hadrosaurus tripos.] Proceedings of the Academy of Natural Sciences of Philadelphia 21:192.

Gilmore, C. W. 1945. Parrosaurus, n. name, replacing Neosaurus Gilmore 1945. Journal of Paleontology 19(5):540.

Gilmore, C. W., and D. R. Stewart. 1945. A new sauropod from the Upper Cretaceous of Missouri. Journal of Paleontology 19(1):23–29.

Lull, R. S., and N. E. Wright. 1942. Hadrosaurian dinosaurs of North America. Geological Society of America Special Paper 40.