Compact Thescelosaurus Year Nine

October and National Fossil Day have rolled around again (check out the fall 2024 Park Paleontology News, too!), so it's time to take a look at the previous year's changes to The Compact Thescelosaurus and welcome some new content. First, the new stuff: I'm sure you'll be shocked to find out I've followed up Triassic pseudosuchians with... Jurassic pseudosuchians. I'm rearranging the pseudosuchian content a bit, to have the non-crocodylomorphs on one sheet and the crocodylomorphs on another. This was done to forestall the deployment of an unwieldy number of "subdivision" columns. Provided I get far enough along, something similar might have to happen with the new sheet around Crocodylia or so. Anyway, the main takeaways I got out of Jurassic pseudosuchians are 1) there's been a lot of work on thalattosuchians over the past couple of decades, and 2) I've discovered I'm not very fond of thalattosuchians and certainly don't mind that they conk out midway through the Cretaceous.

Hey, it's the Science Museum "Goniopholis" again! (Most Jurassic pseudosuchians are thalattosuchians, but North America is largely bereft of the darlings, so we make do with crocs like these.)

The past twelve months were quite a bit more busy than we saw for the 2023 or 2022 updates, with 101 entries in the update sheet. For new taxonomy, there were 73 new species (1 of which had to be given a new genus name due to preoccupation) and 5 existing species were transferred to new genera; 2 older genus names were also revalidated. For removals, 1 species was sunk into another, and 7 were removed altogether as representing groups outside of the purview of The Compact Thescelosaurus. The closest thing to a lull was August, with "only" 4 updates.

In terms of geologic time, the 73 new species were overwhelmingly Cretaceous (11 Early, 40 Late, and 2 uncertain Cretaceous). Otherwise, there were 8 from the Triassic (4 Middle, 1 Middle or Late, and 3 Late) and 12 from the Jurassic (3 Early, 5 Middle, shockingly, and 4 Late).

Geographically, 20 names came from Asia (omitting Jordan as having been on the African Plate during the Cretaceous), 18 came from North America, 15 came from South America, 11 came from Europe, 7 came from Africa, and there was 1 each from Antarctica and Australia. You'll never believe this but the top three countries were China (13), the United States (13), and Argentina (8). After those it was a jump down to Brazil with 5 and Morocco and the United Kingdom with 4, then Japan and Mexico with 3, Canada, Germany, Mongolia, and Spain with 2 apiece, and 12 countries (or continents with no countries) with 1 apiece (Angola, Antarctica, Australia, Colombia, France, Jordan, Kyrgyzstan, Portugal, Russia, Switzerland, Uruguay, and Zimbabwe).

Taxonomically, we had:

1 new aetosaur species:
Garzapelta muelleri

4 new ichthyosaur species:
Argovisaurus martafernandezi
Ichthyotitan severnensis
Mixosaurus luxiensis
Platypterygius elsuntuoso (which for my purposes gets quotation marks around the genus name)

7 new mosasauroid species:
Bentiabasaurus jacobsi
Ectenosaurus shannoni
Ectenosaurus tlemonectes
Jormungandr walhallaensisi
Khinjaria acuta
Megapterygius wakayamaensis
Yaguarasaurus regiomontanus
Another great year for mosasaurs.

3 new plesiosaur species:
Franconiasaurus brevispinus
Marambionectes molinai
Unktaheela specta

2 new pseudosuchian species:
Benggwigwishingasuchus eremicarminis
Parvosuchus aurelioi

8 new pterosaur species:
Akharhynchus martilli
Ceoptera evansae
Cratonopterus huabei
Haliskia peterseni
Inabtanin alarabia
Meilifeilong youhao
Propterodactylus frankerlae
Torukjara bandeirae
That's also a pretty good haul for pterosaurs.

1 new basal sauropterygian species:
Dianmeisaurus mutaensis

15 new theropod species:
Alpkarakush kyrgyzicus
Asiatyrannus xui
Caletodraco cottardi
Diuqin lechiguanae
Dornraptor normani
Eoneophron infernalis
Harenadraco prima
Hypnovenator matsubaraetoheorum
Jaculinykus yaruui
Kiacursor longipes
Koloken inakayali
Labocania aguillonae
Riojavenatrix lacustris
Tyrannosaurus mcraeensis
Urbacodon norelli
With 15 species, there was a decent phylogenetic and geographic spread, albeit almost entirely in the Cretaceous (Alpkarakush and Dornraptor being the exceptions). The one group with an unusually good year was Troodontidae, with Harenadraco, Hypnovenator, and Urbacodon norelli. Also of note: 3 of the species went to existing genera. Tyrannosaurus isn't all that surprising, but Labocania and Urbacodon were probably not high on anyone's predictions for receiving new species.

2 new "prosauropod" species:
Musankwa sanyatiensis
Qianlong shouhu

11 new sauropod species:
Ardetosaurus viator
Bustingorrytitan shiva
Campananeyen fragilissimus
Gandititan cavocaudatus
Inawentu oslatus
"Jingia" dongxingensis (preoccupied, quickly renamed Jingiella)
Qunkasaura pintiquiniestra
Sidersaura marae
Tiamat valdecii
Titanomachya gimenezi
Udelartitan celeste
As you might guess from the numerous links, most of these were titanosaurs. Of the rest, Campananeyen and Sidersaura were rebbachisaurids and Ardetosaurus viator was another diplodocoid, leaving only Jingiella to represent the rest of Sauropoda.

1 new basal ornithischian species:
Gondwanax paraisensis

4 new thyreophoran species:
Bayinosaurus baojiensis
Datai yingliangis
Thyreosaurus atlasicus
Yanbeilong ultimus
Only Datai is not a stegosaur. It's pretty rare to get even 1 stegosaur in a year, so getting 3 is pretty unusual.

1 new nebulous neornithischian species:
Fona herzogae

5 new marginocephalian species:
Gremlin slobodorum
Lokiceratops rangiformis
Sasayamagnomus saegusai
Sphaerotholus lyonsi
Sphaerotholus triregnum
Another scatter, including two pachycephalosaur species added to Sphaerotholus, two hornless horned dinosaurs, and centrosaurine Lokiceratops.

8 new ornithopod species:
Ampelognathus coheni
Chakisaurus nekul
Coahuilasaurus lipani
Comptonatus chasei
Hesperonyx martinhotomasorum
Minqaria bata
Qianjiangsaurus changshengi
Tietasaura derbyiana
There's a couple of elasmarians (Chakisaurus and Tietasaura), a couple of hadrosaurids (Coahuilasaurus and Minqaria), and a bunch of everything else.

5 species were transferred to new genera:
Plesiosaur Dolichorhynchops bonneri to Martinectes
Plesiosaur Dolichorhynchops tropicensis to Scalamagnus
Pseudosuchian Prestosuchus loricatus to Schultzsuchus
Pterosaur Shenzhoupterus sanyainus to Meilifeilong
Plesiosaur Simolestes keileni to Lorrainosaurus

2 old genera were redeployed:
Megapnosaurus for Coelophysis rhodesiensis
Myopterygius for Platypterygius campylodon and P. bannovkensis

1 species was sunk:
"Gyposaurus" sinensis into Lufengosaurus huenei

Finally, 7 species were removed:
Actiosaurus gaudryi (from Choristodera; had only been there because of similarities to Pachystropheus rhaeticus [see below])
Lusitanosaurus liasicus (from Dinosauria)
Pachystropheus rhaeticus (choristodere to thalattosaurian, which is not the same thing as a thalattosuchian)
Taveirosaurus costae (from Dinosauria)
Teratosaurus bengalensis (pseudosuchian to proterosuchid)
Tsylmosuchus donensis (ditto)
Tsylmosuchus jakovlevi (ditto)

And that takes care of us for another year! If you're not interested in Mesozoic reptiles but are looking for more Minnesota invertebrates, may I recommend an article I wrote for Agate?