Rhynchotherium was first described in 1868 on the basis of a lower jaw from the Miocene of Tlaxcala, Mexico.[3] Later, the type species epithet R. tlascalae was erected for the jaw by Henry Fairfield Osborn in 1918. In 1921, a gomphothere skull from the Mt. Eden area of southern California was described as a subspecies of Trilophodon shepardi (a now-defunct combination for Mastodon shepardi), T. s. edensis,[4] but was subsequently reassigned to Rhynchotherium.[5] Other species subsequently assigned to Rhynchotherium included R. falconeri,[6]R. paredensis, R. browni,[7] and R. simpsoni.[8] It was the closest relative to Cuvieronius, and may be ancestral to it.[9]
Lucas and Morgan (2008) reviewed the taxonomy of Rhynchotherium and concluded that only R. edensis, R. falconeri, R. paredensis, R. browni, and R. simpsoni could be confidently referred to Rhynchotherium.[10] Because the genotype of Rhynchotherium is referable to Gomphotherium, the ICZN was petitioned to conserve the genus by designating R. falconeri as the type species,[11] which it did.[12]
Life restoration of Rhynchotherium falconeri, a North American species of the genus.
Misassigned species
Mastodon shepardi Leidy, 1871
Mastodon euhypodon Cope, 1884 - likely a species of Gomphotherium[10]
Tetrabelodon brevidens Cope, 1889
Dibelodon praecursor Cope, 1893
Rhynchotherium rectidens Osborn, 1923
Aybelodon hondurensis Frick, 1933
Blickotherium blicki Frick, 1933
Rhynchotherium anguirivale Osborn, 1936
Phylogenetic position according to Mothé et al. (2016)[9]
^Arroyo-Cabrales, J.; Polaco, O. J.; Laurito, C.; Johnson, E.; Alberdi, M. T.; Zamora, A. L. V. (2007). "The proboscideans (Mammalia) from Mesoamerica". Quaternary International. 169–170. Elsevier: 17–23. Bibcode:2007QuInt.169...17A. doi:10.1016/j.quaint.2006.12.017.
^FALCONER, H. (1868): Paleontological Memoirs. Volume II: 74 –75; London (Hardwicke).
^C. Frick. 1921. Extinct vertebrate faunas of the badlands of Bautista Creek and San Timoteo Canyon, southern California. University of California Publications in Geology 12(5):277-424
^FRICK, C. (1933): New Remains of Trilophodont-Tetralophodont mastodons. – Bulletin American Museum of Natural History, 59: 505 – 652.
^OSBORN, H. F. (1923): New subfamily, generic and specific stages in the evolution of the proboscidea. – American Museum Novitates, 99: 1– 4.
^OSBORN, H. F. (1936): Proboscidea: a monograph of the discovery, evolution, migration, and extinction of the mastodonts and elephants of the world, vol. 1: Moeritherioidea, Deinotherioidea, Mastodontoidea. New York (The American Museum Press).
^OLSEN, S. J. (1957): A new beak-jawed mastodont from Florida. – Journal of the Palaeontological Society of India, 2: 131–135.
^ abLUCAS, S.G. & MORGAN, G.S., 2008. Taxonomy of Rhynchotherium (Mammalia, Proboscidea) from the Miocene-Pliocene of North America.- New Mex. Mus. Nat. Hist. Sci. Bull. 44: 71-87.
^LUCAS, S. G. (2010): Rhynchotherium Falconer, 1868 (Mammalia; Proboscidea): proposed conservation of usage by designation of Rhynchotherium falconeri OSBORN, 1923 as the type species. – Bulletin of Zoological Nomenclature, 67: 158 –162.
