Roundup on Thunderstorm Ridge: keeping up with Petrified Forest NP

Last week's publication of the stem-caecilian Funcusvermis reminded me that I really ought to show off Petrified Forest National Park (PEFO) more often. Since the last spotlight, on the "biloph" trilophosaur Trilophosaurus phasmalophus in spring 2020, four more species of Triassic vertebrates have been described from fossils found in the park, to go along with a bushel of reports on anatomy, identifications of rare forms, vertebrate trace fossils, stratigraphy and geochronology, and other topics, to say nothing of conference abstracts and papers that mention PEFO fossils in wider contexts. (SVP conferences are usually good for a handful of PEFO topics.) Because we're talking the Late Triassic, the taxonomic diversity is wide. There's a little bit of almost everything.*

*Interestingly enough, that includes Paleozoic marine invertebrates: reworked fossiliferous cobbles of the Permian Kaibab Formation have been found in the park's Chinle Formation outcrops, particularly the Sonsela Member. There are also limited Neogene deposits with Hemphillian vertebrates.

Classically, as with most places that have produced vertebrate fossils for more than a century, big singular fossils were long the focus (e.g., skulls of phytosaurs). Although there is still interest in those kinds of fossils, increasingly study has focused on bonebeds and microvertebrates, with much more care given to stratigraphic placement. It turns out that PEFO holds a whole weird and wonderful landscape of everything that gave it a go in the Late Triassic, before a couple of groups of archosaurs took over land management for the rest of the Mesozoic. (And if you don't like vertebrates, the plants are just about as wild in their own way, and there are freshwater and terrestrial invertebrates as well.) It practically begs for a book like those on Florissant, Fossil Lake, the Morrison, and the White River Badlands.

Here's a strat column to help keep the geologic units straight, borrowed from the park website.

With all of that in mind, here are a few quick hits from the past few years of research at PEFO:

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).

Platteville fossils in Cottage Grove

Cottage Grove, Minnesota is not noted as a geological wonderland, although Cottage Grove Ravine Regional Park certainly has its charms if you are willing to put in a little shoe leather. There are also scattered outcrops of the St. Peter Sandstone. However, persistence may be rewarded. Back in November I came across a couple of small fossiliferous blocks in town.

The first thing to do was to figure out the stratigraphy. The rocks were not in situ, but they were not heavily worn, either; in other words, they hadn't fallen off a glacier. The rocks of the area included outcrops of the St. Peter, and initially I wondered if I'd stumbled on a stray carbonate lens in the upper part of the formation. A rather more likely identity, though, is as erosional lag from the Platteville. In fact, the rocks look not unlike the occasional poorly dolomitized intervals I've seen in the Mifflin, and the fossils are certainly appropriate.

A (relatively) large brachiopod shell, among numerous teeny-tiny crinoid columnals and other fragments.

They include a mix of the BBC (brachiopods, bryozoans, and crinoids). There is also one object that looks like a whorl of a small Phragmolites sticking out. A couple of notable features include the small size of the fossils, particularly the crinoids; and the density of small fossil fragments and elements.

A different relatively large brachiopod shell among numerous teeny-tiny crinoid columnals and other fragments; note some nice bryozoan fragments on the left.

A hash of tiny fragments.

See what looks like tire tread near the center? That's what reminds me of Phragmolites.

Before we sign off for the year, I'd like to note that for some reason, over the past few weeks the "Fossil Felids of the National Park Service" post has been attracting a few dozen views a week. (Considering I don't do any external promotion and have reduced my social media presence from "negligible" to "zero", this is a lot!) I have no idea where this is coming from (probably picked up by a group somewhere that doesn't register in stats) or why it should have attracted interest (well, felines, I suppose, or maybe Pleistocene megafauna or predators in general), but I'm not complaining! Someone who actually knows something about cats could probably make an interesting and well-attended series like "Your Friends The Titanosaurs".

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.

Your Friends The Titanosaurs: Caieiria allocaudata

This edition of "Your Friends The Titanosaurs" is a little different in that not only are we welcoming a new friend, we are saying goodbye to an old friend. The latter is something that should come as no surprise; with well over a hundred species, notorious for incomplete material, some of them are eventually going to turn out to be the same.

(Also, I should have mentioned this, but I moved the external links to a separate page to conserve space on the sidebar.)

Quick Guide to Fossils at Uŋčí Makhá Park

So I went back to Uŋčí Makhá Park last weekend and spent a couple of hours taking photos of fossils, because it makes such an ideal place to see the upper Platteville fauna. After all, a winter of freezes and thaws may not leave these new exposures looking as nice as they do now. Here's a quick guide to what can be seen there. (Let's see how many photos I can squeeze into one post, and how many species I can misidentify!)

Determining where you are stratigraphically

First of all, I'd just like to reiterate the stratigraphy. Most of the vertical extent is in the Magnolia Member of the Platteville Formation, with the upper part composed of the Carimona Member of the Decorah Shale. I'm thinking more or less the entire extent of the Carimona is exposed, based on thickness; at any rate the next thing up would be the shaly part of the Decorah, and there isn't a trace of it to be seen. I'm suspicious because the difference is just so darn clear, but at this site there is an unmistakable color change between the two units: the Carimona is the upper blue-gray interval and the Magnolia is the light tan-gray interval below. The Deicke K-bentonite is the lower and thicker of the two bentonite gaps in the Carimona. (Note that the Carimona is sometimes supplemented or replaced by landscaping, but this is pretty obvious.) As you walk from south to north, the "floor" goes up stratigraphically, so it's not all one bedding plane but a gently rising series of planes, until by the exit you're close to the color change.

The color change is quite evident here. The Deicke K-bentonite is the cut-in about halfway up the blue-gray Carimona (above the scale bar in the center of the photo).

Here we've gone north, and the floor has risen. The Deicke is still the seam in the middle of the blue-gray rocks.