Stangerochampsa

Stangerochampsa is an extinct genus of globidontan alligatoroid, possibly an alligatorine or a stem-caiman, from the Late Cretaceous of Alberta. It is based on RTMP.86.61.1, a skull, partial lower jaws, and partial postcranial skeleton discovered in the late Campanian–early Maastrichtian-age Horseshoe Canyon Formation. Stangerochampsa was described in 1996 by Wu and colleagues. The type species is S. mccabei. The generic name honors the Stanger family, the owners of the ranch where the specimen was found, and the species name honors James Ross McCabe, who discovered, collected, and prepared it. Stangerochampsa is described as "small to medium–sized"; the type skull is 20.03 centimetres (7.89 in) long from the tip of the snout to the occipital condyle, and is 13.0 centimetres (5.1 in) wide at its greatest, while the thigh bone is 14.2 centimetres (5.6 in) long. It had heterodont dentition, with large crushing teeth at the rear of the jaws.[1]

Stangerochampsa
Temporal range: Late Cretaceous
Skeletal mount on display at the National Museum of Natural History.
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Crocodilia
Clade: Globidonta
Genus: †Stangerochampsa
Wu et al., 1996
Type species
†Stangerochampsa mccabei
Wu et al., 1996

Classification

Wu and colleagues, using phylogenetic analyses, found their new genus to be closest to Brachychampsa, and then Albertochampsa and Hylaeochampsa successively, as part of a clade within Alligatorinae that also included Allognathosuchus, Ceratosuchus, and Wannaganosuchus. This arrangement also unites most Mesozoic and Paleogene alligatorines.[1] Brochu (1999), in an analysis of all alligatoroids, found Stangerochampsa and Brachychampsa to be just outside Alligatoridae, and suggested that Stangerochampsa and Albertochampsa were synonymous.[2] Brochu (2004)[3] and Hill and Lucas (2006)[4] also found Stangerochampsa to be outside of Alligatorinae; Hill and Lucas found Albertochampsa to its sister taxon.[4] On the other hand, in the phylogenetic analysis conducted by Bona et al. (2018) Stangerochampsa was recovered as an alligatorid, specifically as a stem-caiman.[5]

gollark: ```Manufactured in week 18 of year 2012Specified cycle count over device lifetime: 10000Accumulated start-stop cycles: 1967Specified load-unload count over device lifetime: 300000Accumulated load-unload cycles: 1967Elements in grown defect list: 4```
gollark: (my server's HDD, I checked with `smartctl`)
gollark: "Manufactured in week 18 of year 2012"
gollark: I don't know how old it is exactly, but I kind of expect it to randomly fail at any moment.
gollark: It's on an ancient 7200RPM SAS disk.

References
  1. Wu, Xiao-Chun; Brinkman, Donald B.; Russell, Anthony P. (1996). "A new alligator from the Upper Cretaceous of Canada and the relationships of early eusuchians" (PDF). 39 (2): 351–375. Archived from the original (PDF) on 2011-09-28. Cite journal requires |journal= (help)
  2. Brochu, C. A. (1999). "Phylogenetics, taxonomy, and historical biogeography of Alligatoroidea". Society of Vertebrate Paleontology Memoir. 6: 9–100. doi:10.2307/3889340.
  3. Brochu, Christopher A. (2004). "Alligatorine phylogeny and the status of Allognathosuchus Mook, 1921". Journal of Vertebrate Paleontology. 24 (4): 857–873. doi:10.1671/0272-4634(2004)024[0857:APATSO]2.0.CO;2. JSTOR 4524781.
  4. Hill, Robert V.; Lucas, Spencer G. (2006). "New data on the anatomy and relationships of the Paleocene crocodylian Akanthosuchus langstoni" (pdf). Acta Palaeontologica Polonica. 51 (3): 455–464.
  5. Paula Bona; Martín D. Ezcurra; Francisco Barrios; María V. Fernandez Blanco (2018). "A new Palaeocene crocodylian from southern Argentina sheds light on the early history of caimanines". Proceedings of the Royal Society B: Biological Sciences. 285 (1885): 20180843. doi:10.1098/rspb.2018.0843. PMC 6125902. PMID 30135152.
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