Sunday, October 9, 2022

Compact Thescelosaurus Year Seven

Here we are at the second weekend of October, which means it's time for three things: National Fossil Day; a new sheet for The Compact Thescelosaurus; and our annual roundup of what's been added to the spreadsheet. National Fossil Day falls on Wednesday, October 12 this year, although events occur throughout the month (especially the weekends before and after), so check your nearest museum or National Park System unit for events! Our fall Park Paleontology newsletter is also up for viewing (including more fun with packrats).

For this year's addition to The Compact Thescelosaurus, I have chosen phytosaurs. One particular challenge with them is that for a while it seemed that every few years half the species switched to different genera. Annoyingly enough many have stuck on Machaeroprosopus. (I say annoyingly because I hate writing Machaeroprosopus, about as much as I hate writing Ophthalmosaurus.) I relied on two recent publications, Stocker and Butler (2013) and Jones and Butler (2018), for the basics. To be honest I have no business putting up an authoritative-looking spreadsheet on phytosaur species, but I could say the same thing about all of them after the original.

A phytosaur attacks a dicynodont at the New Mexico Museum of Natural History and Science.

Now, for our yearly accounting: Since October 10, 2021, there have been 77 updates. There were 55 new species (well, technically 56 but Javelinadactylus sagebieli and Wellnhopterus brevirostris are the same thing), 4 existing species moved to new genera, 4 reinstated species (including 1 given a new genus), and 2 sunk species. These were not spread evenly throughout the year. Rather, there was a slug in November–December 2021, another bunch in February–March 2022, burps in May and July, and a final burst August–September.

Considering the 55 new additions, in terms of age the Cretaceous again supplied the most, but the slant was not as strong and the Triassic had a strong showing. 14 came from the Triassic (1 Early, 5 Middle, and 8 Late). 10 came from the Jurassic (2 Early, 1 Early–Middle, 3 Middle, 1 Middle–Late, and 3 Late). 29 came from the Cretaceous (1 overall, 6 Early, and 22 Late). Finally, there were 2 from the Paleocene (choristoderes).

Geographically, Asia led with 17 species, followed by South America (15), Europe (10), North America (8), Africa (4), and Australia (1). (For anyone checking my numbers, the 2 Russian species included 1 Asian and 1 European form, and the species from Denmark was counted as North American because it came from Greenland.) Argentina and China tied for most productive country with 9 apiece, followed by the USA (7), a three-way tie between Brazil, Mongolia, and the UK with 4, Germany and Russia with 2, and then the field (Angola, Australia, Chile, Colombia, Denmark, Japan, Kazakhstan, Morocco, Portugal, South Africa, Spain, Switzerland, Uzbekistan, and Zimbabwe with 1 each).

Taxonomically, we had:

2 new basal avemetatarsalian species:
Gamatavus antiquus
Maehary bonapartei

2 new choristodere species:
Champsosaurus norelli
Kosmodraco magnicornis

6 new ichthyosaur species:
Auroroborealia incognita
Basiesaurus robustus
Cymbospondylus duelferi
Kazakhstanosaurus efimovi
Kazakhstanosaurus shchuchkinensis
Magnipterygius huenei
Another good year for ichthyosaurs.

1 new mosasaur species:
Thalassotitan atrox

3 new plesiosaur species:
Eardasaurus powelli
Eiectus longmani
Serpentisuchops pfisterae

9 (or 10) new pterosaur species:
Cascocauda rong
Dearc sgiathanach
Epapatelo otyikoloko
Lingyuanopterus camposi
Pachagnathus benitoi
Quetzalcoatlus lawsoni
Thanatosdrakon amaru
Wellnhopterus brevirostris (Javelinadactylus sagebieli)
Yelaphomte praderioi
Nobody went out of their way to coin easily spelled pterosaur names over the past twelve months. It's a fairly wide spread across the pterosaurian spectrum.

4 new basal sauropterygian species:
Honghesaurus longicaudalis
Nothosaurus luopingensis
Pomolispondylus biani
Prosantosaurus scheffoldi

12 new theropod species (classic dinosaurs only):
Berthasaura leopoldinae
Dzharaonyx eski
Elemgasem nubilus
Guemesia ochoai
Iberospinus natarioi
Khulsanurus magnificus
Kuru kulla
Maip macrothorax
Meraxes gigas
Ondogurvel alifanovi
Paralitherizinosaurus japonicus
Vectiraptor greeni
Anyone playing Argentina, Cretaceous, or Mongolia in their theropod pool came up a winner this year. Abelisauroids (3) and alvarezsaurids (3) were the champs; abelisaurs often come up strong, but alvarezsaurs were a surprise.

2 new basal sauropodomorph species:
Issi saaneq
Mbiresaurus raathi

5 new sauropod species:
Abditosaurus kuehnei
Ibirania parva
Perijasaurus lapaz
Rhomaleopakhus turpanensis
Tuebingosaurus maierfritzorum
Boring versus the previous year, but titanosaurs still come out looking good.

5 new thyreophoran species:
Bashanosaurus primitivus
Jakapil kaniukura
Stegouros elengassen
Tarchia tumanovae
Yuxisaurus kopchicki
Thyreophorans had an even better year than their good numbers indicate, with the noteworthy Jakapil and Stegouros exemplifying heretofore unknown lineages of armored dinosaurs.

1 new ceratopsian species:
Bisticeratops froeseorum

3 new iguanodontian species:
Brighstoneus simmondsi
Iyuku raathi

Kelumapusaura machi
Ceratopsians and ornithopods usually do better; we'll chalk it up as an off-year.

4 species were transferred to new genera:
Kronosaurus boyacensis to Monquirasaurus
"Ornithocheirus" platystomus to Draigwenia
Platypterygius sachicarum to Kyhytysuka
Simoedosaurus dakotensis to Kosmodraco

4 species were reinstated:
Amblydectes crassidens
Aoniraptor libertatum
"Ichthyosaurus" zetlandicus (as Temnodontosaurus zetlandicus)
"Kritosaurus" australis (under new genus Huallasaurus)

2 species were sunk:
"Ornithocheirus" eurygnathus into Amblydectes crassidens
Sahaliyania elunchunorum into Amurosaurus riabinini


Jones, A. S., and R. J. Butler. 2018. A new phylogenetic analysis of Phytosauria (Archosauria: Pseudosuchia) with the application of continuous and geometric morphometric character coding. PeerJ 6:e5901 doi:10.7717/peerj.5901.

Stocker, M. R., and R. J. Butler. 2013. Phytosauria. Pages 91–117 in Anatomy, phylogeny, and palaeobiology of early archosaurs and their kin. Geological Society, London, United Kingdom. Special Publication 379.

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