Sunday, October 16, 2016

Year One of The Compact Thescelosaurus (now with extra choristoderes)

Mid-October is the time of National Fossil Day, as well as just past the anniversary date of the late lamented Thescelosaurus! and the introduction of The Compact Thescelosaurus. In honor of the occasion, I've made a couple of additions. One is a new page with a selection of online museum collections databases. The other is a new worksheet on The Compact Thescelosaurus, featuring choristoderes. This sheet is the first of what I hope to be a series covering other fossil groups; choristoderes were selected for the honor this time around because there are only a few. I have a few candidates in mind for the next addition, perhaps a year from now; it depends on how ambitious I'm feeling. I haven't given up on the idea of making a version of the old website's contents available, but I haven't really decided how to do it.

So it's not really surprising that I came up with a post on subtle nuances of the nomenclature of Champsosaurus.

With slightly over a year of the database being live, what has changed? Let's go to the Updates worksheet. One thing I really like about the Wiki model is the preservation of page history, and I decided that I would try to replicate this in spirit with the Updates by recording changes to classification, formations, timing, etc., instead of just additions and removals. There are 93 entries since the beginning. A quick examination shows the following:

On the growth side of the ledger, 41 names were introduced, either as new species (34) or as reintroductions of old species (7). 34 new names is about on par with a typical year this decade (more so if I also credit it with two names that were not included; see below). Of the new names, the Upper Cretaceous is the clear champ as a source, with only 3 Jurassic species total and 5 Lower Cretaceous species. North America contributed 12 species, Asia contributed 9, South America contributed 8, Europe contributed 4, and Australia contributed 1. The nations were the usual suspects, with Australia, Japan, Mexico, and Thailand being about the most atypical. The US had 7, Argentina 6, and China 5. In any given year since the 1980s these three will usually be in the top 5, so no surprise there. The breakdown is as follows:

14 new theropod species:
Aoniraptor libertatum
Apatoraptor pennatus
Boreonykus certekorum
Dakotaraptor steini
Dracoraptor hanigani
Fukuivenator paradoxus
Gualicho shinyae
Murusraptor barrosaensis
Rativates evadens
Taurovenator violantei
Timurlengia euotica
Tototlmimus packardensis
Viavenator exxoni
Wiehenvenator albati
This is a little bit of everything, phylogenetically speaking, although 2 ornithomimids (Rativates evadens and Tototlmimus packardensis) is a bit of a quirk.

5 new sauropod species:
Austroposeidon magnificus
Lohuecotitan pandafilandi
Notocolossus gonzalezparejasi
Sarmientosaurus musacchioi
Yunxianosaurus hubeinensis
As usual, the titanosaurians continue to sweep up. All four of the valid species (Yunxianosaurus hubeinensis turned out to be informal) are from Upper Cretaceous rocks, and three of them are from South America (Lohuecotitan pandafilandi being the exception). Titanosaur dominance will probably not let up anytime in the near future, either.

3 new thyreophoran species:
Gastonia lorriemcwhinneyae
Kunbarrasaurus ieversi
Tarchia teresae
All three are ankylosaurians, and all three are either based on previously described material or were known informally to the community before naming.

5 new ceratopsian species:
Agujaceratops mavericus 
Hualianceratops wucaiwanensis
Ischioceratops zhuchengensis
Machairoceratops cronusi
Spiclypeus shipporum
A couple of basal ceratopsians and a few more ceratopsids, although at some point the pendulum is going to swing back to more conservative taxonomy for horned dinosaurs.

7 new ornithopod species:
Datonglong tianzhenensis
Eotrachodon orientalis
?Gryposaurus alsatei
Morelladon beltrani
Probrachylophosaurus bergei
Sirindhorna khoratensis
Zuoyunlong huangi
Remember when the only things between Dryosaurus and duckbills were Camptosaurus, Iguanodon, Muttaburrasaurus, Ouranosaurus, and Probactrosaurus? I kind of miss that. Definitely an area where you can't tell the players without a program.

7 reinstatements:
"Brachylophosaurus" goodwini
Diracodon laticeps
Hoplosaurus ischyrus
Leipsanosaurus noricus
"Monoclonius" cutleri
"Tyrannosaurus" luanchuanensis
Velocipes guerichi
Almost all of these are dubious species brought back because they weren't diagnostic enough to merit a definitive sinking. The exception is Velocipes guerichi, which had been exiled out of Dinosauria.

On the other hand, 11 names were removed or were not added in the first place. I judged Lepidocheirosaurus natalis a synonym before it could be added, and I withheld Beipiaognathus jii as a chimera; it's not that it wasn't named in a valid way, but that in the absence of a re-analysis of the specimen it is not clear what the "type individual" is, or if the "type individual" belongs to an existing species.

8 sinkings:
Aoniraptor libertatem into Gualicho shinyae
Becklespinax altispinax into Altispinax dunkeri
Chasmosaurus brevirostris indeterminate within Chasmosaurus
Chasmosaurus kaiseni indeterminate within Chasmosaurus
Lepidocheirosaurus natatalis into Kulindadromeus zabaikalicus
Monoclonius canadensis indeterminate within Chasmosaurus
Stormbergia dangershoeki into Lesothosaurus diagnosticus
Tyrannosaurus lancensis into Tyrannosaurus rex

2 deletions:
Spondylosoma absconditum (Schrödinger's archosaur)
Yunxianosaurus hubeinensis (nomen nudum)

1 withheld as a chimera:
Beipiaognathus jii

There were also three lateral moves, giving new generic names to existing species:
Alcovasaurus longispinus for "Stegosaurus" longispinus
Meroktenos thabanensis for "Melanorosaurus" thabanensis
Or moving a species to another genus:
Uteodon aphanoectes to Camptosaurus

28 other entries dealt with species being moved to different clades. Of the remainder, most were of the "tweaked the age of a formation" or "tweaked geographic/geologic assignments." I made a couple of significant shifts, one of which moved most of the hypsilophodont-grade ornithischians out of Ornithopoda, another that returned them, and one which pulled Megaraptora out of Carnosauria and left them at Avetheropoda until such time as there is consensus on whether or not they are carnosaurians or coelurosaurians.


  1. I love these sort of posts, a nice overlook of the changes since the database's creation.

    Anyway, out of curiosity, what groups do you plan to add? I know you told me Pterosauria is one.

    1. Of the groups I've considered, Pterosauria is the one I'm most comfortable working with, so it will probably be sooner rather than later. The various other Mesozoic classics are also candidates: sauropterygians (I have a soft spot for plesiosaurs), ichthyopterygians, mosasauroids, phytosaurians, various pseudosuchians, etc. If I have not been driven mad by this point, perhaps I'd do at least Mesozoic birds. Another possibility is some kind of table for my local Ordovician invertebrates, although there are some real headaches based on how recently someone bothered to look at a given group.