Machaeroprosopus

Machaeroprosopus
Temporal range: Late Triassic, 228–209 Ma
Skulls in New Mexico
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauromorpha
Clade: Archosauriformes
Order: †Phytosauria
Family: †Parasuchidae
Tribe: †Mystriosuchini
Genus: †Machaeroprosopus
Mehl et al., 1916 [1]
Type species
†Belodon buceros
Species
  • †M. andersoni Mehl, 1922
  • †M. buceros (Cope, 1881)
  • †M. jablonskiae (Parker & Irmis, 2006) [2]
  • †M. lottorum Hungerbühler et al., 2013 [3]
  • †M. mccauleyi (Ballew, 1989) [4]
  • †M. pristinus (Mehl, 1928)
  • †M. validus Mehl in Mehl et al., 1916 [1]
Synonyms
  • Arribasuchus Long & Murry, 1995 [5]
  • Machaeroprosopus tenuis Camp, 1930
  • Pseudopalatus Mehl, 1928

Machaeroprosopus (from Greek: μαχαίρα machaíra, 'large knife' and Greek: πρόσωπος prósōpos, 'bordering on')[6] is an extinct genus of mystriosuchin leptosuchomorph phytosaur from the Late Triassic of the southwestern United States. M. validus, once thought to be the type species of Machaeroprosopus, was named in 1916 on the basis of three complete skulls from Chinle Formation, Arizona. The skulls have been lost since the 1950s, and a line drawing in the original 1916 description is the only visual record of the specimen.[7] Another species, M. andersoni, was named in 1922 from New Mexico, and the species M. adamanensis, M. gregorii, M. lithodendrorum, M. tenuis, and M. zunii were named in 1930. Most species have been reassigned to the genera Smilosuchus,[8] Rutiodon, or Phytosaurus.[9] Until recently, M. validus was considered to be the only species that has not been reassigned. Thus, Machaeroprosopus was considered to be a nomen dubium or "doubtful name" because of the lack of diagnostic specimens that can support its distinction from other phytosaur genera. However, a taxonomic revision of Machaeroprosopus, conducted by Parker et al. in 2013, revealed that UW 3807, the holotype of M. validus, is not the holotype of Machaeroprosopus, while the species Machaeroprosopus buceros, Machaeroprosopus being a replacement name, with a fixed type species, for Metarhinus, is the combinatio nova of the type species of the genu: Belodon buceros. Therefore, the name Pseudopalatus must be considered a junior synonym of Machaeroprosopus, and all species of the former must be reassigned to the latter.[10] This revised taxonomy was already accepted in several studies, including Stocker and Butler (2013).[11] Stocker and Butler (2013) also treated M. andersoni as a valid species,[11] and not a junior synonym of Machaeroprosopus buceros as was previously suggested by Long and Murry (1995).[5]

  1. ^ a b Cite error: The named reference Mehletal1916 was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference ParkerIrmis06 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference M.lottorum was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Ballew89 was invoked but never defined (see the help page).
  5. ^ a b Long, R. A.; Murry, P. A. (1995). "Late Triassic (Carnian and Norian) tetrapods from the southwestern United States". New Mexico Museum of Natural History and Science Bulletin. 4: 1–254.
  6. ^ Colbert, Edwin H. (Edwin Harris); Knight, Charles Robert (1951). The dinosaur book : the ruling reptiles and their relatives. New York: McGraw-Hill. p. 150.
  7. ^ Parker, Bill (7 February 2007). "The Tragic Tale of Machaeroprosopus and Acompsosaurus". Chinleana. Field of Science. Archived from the original on 15 April 2012. Retrieved 11 May 2012.
  8. ^ Stocker, Michelle R. (2010). "A new taxon of phytosaur (Archosauria: Pseudosuchia) from the Late Triassic (Norian) Sonsela Member (Chinle Formation) in Arizona, and a critical reevaluation of Leptosuchus Case, 1922". Palaeontology. 53 (5): 997–1022. doi:10.1111/j.1475-4983.2010.00983.x. S2CID 83536253.
  9. ^ Gregory, J.T. (1962). "The relationships of the American phytosaur Rutiodon" (PDF). American Museum Novitates (2095): 1–22.
  10. ^ Parker, W. G.; Hungerbühler, A.; Martz, J. W. (2013). "The taxonomic status of the phytosaurs (Archosauriformes) Machaeroprosopus and Pseudopalatus from the Late Triassic of the western United States". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 103 (3–4): 265–268. doi:10.1017/S1755691013000339. S2CID 84739408.
  11. ^ a b Stocker, M. R.; Butler, R. J. (2013). "Phytosauria". Geological Society, London, Special Publications. 379 (1): 91–117. Bibcode:2013GSLSP.379...91S. doi:10.1144/SP379.5. S2CID 219192243.