Compact Thescelosaurus Year Eight

It's that time again, for National Fossil Day (October 11 this year), a new sheet for The Compact Thescelosaurus, and the annual summary of what was added to the spreadsheet in the past 12 months. In addition to National Fossil Day events this month, the latest issue of Park Paleontology News is up for viewing. Also in breaking NPS paleontology news: additional dating of the fossil human tracks at White Sands National Park, and a previously overlooked record of a tyrannosaur tooth at Yellowstone National Park. [Update, 2023/10/10: And a tritylodont bonebed at Glen Canyon National Recreation Area was just announced; goes well with this new paper on a massive track block from the recreation area, too.]

Here at Equatorial Minnesota, we've passed 400 entries this year. Later this year, December 15 will mark 10 years of posting. (Also, anyone know why this nautiloid post would have spiked in interest?) The Compact Thescelosaurus has been around for 8 of those years, and it's traditional to add a new sheet. For this year, first I considered all of Pseudosuchia (except for the aetosaurs, covered already), but decided against it due to the number of species. I then looked at doing just Mesozoic pseudosuchians before being discouraged by whatever it is Thalattosuchia has been doing over the past 200 years. So, for now it's just Triassic forms, with the intent to expand over time.

Prestosuchus threatening an Eoraptor in the "Ultimate Dinosaurs" exhibition at the Science Museum of Minnesota, May 2014.

Now, the yearly roundup: Again there were 78 updates since our last check-in, on October 9, 2022. Of these, on the credit side there were 57 new species, 3 overlooked species, 1 moved to a new genus, and 1 added after further consideration. On the other hand, 9 previously established species were sunk, making this our busiest year for synonymizations. The flow of updates was fairly constant, with lows in October, December, March, and April, a high in November, and a head of steam building since about May. The headline group, Dinosauria, took it on the chin most of the year, with practically all of the new names coming over a couple of weeks in November, a couple of weeks in June, a week in July, and a week in September. Subtracting two sauropods that had been previously overlooked, I'm mildly surprised to find that this period matched the previous for dinosaurs, 28 to 28, but it's not 2023's doing; 10 of the 28 came in the last three months of 2022. Go figure.

Chronologically, of the 57 new species, 11 were Triassic (2 Early, 1 Middle, 1 Middle or Late, and 7 Late). 10 were plain Jurassic (1 Early, 1 Middle, 2 Middle or Late, and 6 Late), and there were 2 Late Jurassic or Early Cretaceous. As usual, the Cretaceous came off the best, with 34 (10 Early and 24 Late). I keep adding Triassic groups but it doesn't seem to inspire them.

Geographically, 17 names came from Asia (omitting India as doing its own thing in the Mesozoic, 13 came from Europe, 12 came from North America, 7 came from South America, 4 came from Africa (omitting Madagascar), 3 came from India, and 1 came from Madagascar. Country-wise the distribution tailed off quickly after China (12) and the United States (10). Spain was the surprise third place with 5, then Argentina, Brazil, Germany, and India tied with 3, and several others had 2 (Egypt, Kazakhstan, Morocco, Portugal, United Kingdom) or 1 (Canada, Chile, Denmark [Greenland], Japan, Madagascar, Mongolia, Romania, and Thailand). Several usual competitors turned in low figures (Argentina, Brazil, Canada, Mongolia, the UK).

Taxonomically, we had:

2 new aetosaur species:
Kryphioparma caerula
Venkatasuchus armatum

3 new basal avemetatarsalian species:
Amanasaurus nesbitti
Mambachiton fiandohana
Venetoraptor gassenae

3 new ichthyosaur species:
Eurhinosaurus quenstedi
Nannopterygius mikhailovi
Nannopterygius yakimenkae

6 new mosasauroid species:
Carentonosaurus algorensis
Carentonosaurus soarensis
"Hainosaurus" boubker
Halisaurus hebae
Sabarosaurus dahli
Stelladens mysteriosus
A pretty good year for mosasauroids, all told.

3 new phytosaur species:
Colossosuchus techniensis
Jupijkam paleofluvialis
Mystriosuchus alleroq

3 new plesiosaur species:
Chubutinectes carmeloi
Plesioelasmosaurus walkeri
Styxosaurus rezaci

5 new pterosaur species:
Balaenognathus maeuseri
Eopteranodon yixianensis
Lusognathus almadrava
Petrodactyle wellnhoferi
Shenzhoupterus sanyainus

4 new basal sauropterygian species:
Chusaurus xiangensis
Luopingosaurus imparilis
Prosaurosphargis yingzishanensis
Wumengosaurus rotundicarpus

7 new theropod species (classic dinosaurs only):
Daspletosaurus wilsoni
Daurlong wangi
Fujianvenator prodigiosus
Migmanychion laiyang
Natovenator polydontus
Protathlitis cintorrensis
Tyrannomimus fukuiensis
The diversity was all right if you like coelurosaurs; otherwise October 2022 to October 2023 was probably not exciting.

8 new sauropod species:
Caieiria allocaudata
Chucarosaurus diripienda
Garumbatitan morellensis
Igai semkhu
Jiangxititan ganzhouensis
Ruixinia zhangi
Tharosaurus indicus
Yuzhoulong qurenensis
Again, the diversity was great if you like somphospondylans, otherwise not.

2 new thyreophoran species:
Patagopelta cristata
Vectipelta barretti

1 new nebulous neornithischian species:
Minimocursor phunoiensis

2 new marginocephalian species:
Furcatoceraops elucidens
Platytholus clemensi

8 new ornithopod species:
Calvarius rapidus
Gonkoken nanoi
Iani smithi
Malefica deckerti
Nevadadromeus schmitti
Oblitosaurus bunnueli
Transylvanosaurus platycephalus
Vectidromeus insularis
It was a good year for ornithopods that weren't hadrosaurids.

1 species was transferred to a new genus:
Huaxiapterus corollatus to Huaxiadraco

1 species was added upon further review:
Galtonia gibbidens (to the aetosaur tab)

3 previously overlooked species were recognized:
Bashunosaurus kaijiangensis (from 2004)
Trematospondylus macrocephalus (overlooked by almost everyone since 1858!)
"Shunosaurus" jiangyiensis (from 2004)

9 species were sunk:
Gravitholus albertae into Stegoceras validum
Hansuessia sternbergi into Stegoceras validum
Huaxiapterus atavismus into Sinopterus dongi
Huaxiapterus benxiensis into Huaxiadraco corollatus
Huaxiapterus jii into Sinopterus dongi
Sinopterus hui into Sinopterus dongi
Sinopterus lingyuanensis into... Sinopterus dongi (what a twist!)
Onychosaurus hungaricus into Zalmoxes robustus
Trigonosaurus pricei into Baurutitan britoi