|Had to lie on my back on the Science Museum lobby floor to get that.|
A couple of comments:
Pterosaur classification lacks consensus. (Ha.) In the face of a lot of mutual incompatibilities, I winged it, no pun intended. I leaned heavily on Andres et al. (2014), with Rodrigues and Kellner (2013) for Ornithocheirus and friends and some Vidovic and Martill (2017) in the ctenochasmatoids. I am fully confident that I have produced a hybrid which will please no one. C'est la vie.
Pterosaur diversity is heavily weighted to just a few units. In roughly chronological order, the most important are:
- The Tiaojishan Formation (early Late Jurassic) of China
- The Solnhofen Formation (late Late Jurassic) and some related units in Germany
- The Jiufotang/Yixian formations (middle Early Cretaceous) of China
- The Santana Group (late Early Cretaceous) of Brazil
- The Cambridge Greensand of the UK (reworked late Early Cretaceous)
Now we come to the review of the previous year. There have been 83 entries on the Updates sheet since October 16, 2016, our last review. The breakdown of the updates is as follows:
42 names were introduced, with 37 new species, 4 reinstatements, and Beipiaognathus jii (withheld at the last update as a potential chimera, accepted on review as dinosaurian). This total is about the same as last year's 41. The temporal diversity is greater, with 4 Late Triassic, 1 Early Jurassic, 1 Middle Jurassic, 3 Late Jurassic, 13 Early Cretaceous, and 15 Late Cretaceous new taxa. Geographically, it's the same top 3 this year, although the order is different (10 for China, 6 for Argentina, and 4 for the United States). This is followed by a three-way tie for fourth (Brazil, Canada, and Spain, 3 each). Other contributors include Australia, the Czech Republic, France, Mexico, Mongolia, Morocco, Russia, and Tanzania (1 each). The taxonomic breakdown is as follows:
1 new dinosauromorph species:
15 new theropod species:
This batch leans heavily on maniraptorans (10 out of 15), the exceptions being Aepyornithomimus tugrikinensis (ornithomimid), Chenanisaurus barbaricus (abelisaurid), Daspletosaurus horner (tyrannosaurid), and two Late Triassic coelophysoids from Argentina (Lucianovenator bonoi and Powellvenator podocitus). The non-maniraptors are equaled by an unusually good year for troodontids (Albertavenator curriei, Daliansaurus liaoningensis, Jianianhualong tengi, Latenivenatrix mcmasterae, and Liaoningovenator curriei).
2 new "prosauropod" species:
Buriolestes schultzi is pretty close to the base of Sauropodomorpha, while Xingxiulong chengi is much closer to Sauropoda.
11 new sauropod species:
Sauropods staged a significant rally, more than doubling last year. As usual, the titanosaurians are the winners. The only non-titanosaurs are Europatitan eastwoodi (for certain values of Titanosauria), Galeamopus pabsti, Moabosaurus utahensis, and two brachiosaurids (Soriatitan golmayensis and Vouivria damparisensis).
3 new thyreophoran species:
I'm tentatively accepting Isaberrysaura as a basal stegosaurian. The thyreophorans made their shots count this year! Along with Patagotitan and Serikornis, these three are among the most memorable newcomers of the past 12 months.
1 new ceratopsian species:
What, no basal ceratopsians?
4 new ornithopod species:
This has been a slow year for ornithopods, with two hadrosaurids (Bonapartesaurus rionegrensis and Laiyangosaurus youngi) and a more basal iguanodont (Magnamanus soriaensis), and a species that is an iguanodont or a more basal ornithopod depending on your tree and definitions (Burianosaurus augustai).
Stenonychosaurus inequalis (genus reinstatement; species had been accepted before)
A mixed bag, with two troodontids from the disintegration of Troodon and housekeeping in Tanius.
On the other side of the ledger, there were 2 removals, 1 genus sunk, 1 old species moved to a new genus and then lost almost immediately, and 1 genus/species accepted as a synonym on arrival:
"Omosaurus leedsi" (nomen nudum)
Razanandrongobe sakalavae (non-dinosaurian)
Ugrunaaluk into Edmontosaurus
1 "death" by misadventure:
"Laelaps" macropus moved to new genus Teihivenator and then killed almost immediately
1 immediate sinking:
Shuangbaisaurus anlongbaoensis into Sinosaurus triassicus
There was also one lateral move of an existing species into a new genus:
"Stegoceras" brevis to Foraminacephale brevis
The other 35 entries in the updates are various moves, reorganizations, and updates to formations, national subdivisions, and higher-level nomenclature.
Andres, B., J. Clark, and X. Xu. 2014. The earliest pterodactyloid and the origin of the group. Current Biology 24(9):1011–1016.
Rodrigues, T., and A. W. A. Kellner. 2013. Taxonomic review of the Ornithocheirus complex (Pterosauria) from the Cretaceous of England. ZooKeys 308:1–112.
Vidovic, S. U., and D. M. Martill. 2017. The taxonomy and phylogeny of Diopecephalus kochi (Wagner, 1837) and ‘Germanodactylus rhamphastinus’ (Wagner, 1851). Geological Society of London Special Publications 455. doi:10.1144/SP455.12.