Rhynchotherium

Rhynchotherium is an extinct genus of proboscidea endemic to North America and Central America during the Miocene through Pliocene from 13.650—3.6 Ma, living for approximately 10 million years.[1]

Rhynchotherium
Temporal range: Miocene–Pliocene
Restoration
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Mammalia
Order:
Proboscidea
Family:
†Gomphotheriidae
Genus:
†Rhynchotherium

Falconer, 1868
Species
  • R. falconeri Osborn, 1923 (type)

This gomphothere had two tusks and may have evolved from Gomphotherium.[2]

Taxonomy

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]

†Gomphotheriidae (Gomphotheres)
 

†Gomphotherium

 
 
 

†Gnathabelodon

 
 
 

†Eubelodon

 
Brevirostrine clade
 

†Stegomastodon

 
 
 

†Sinomastodon

 
 
 

†Notiomastodon

 
 
 

†Rhynchotherium

 
 

†Cuvieronius

 
 
 
 
 
 
 
 

References
  1. Paleobiology database: Rhynchotherium basic info
  2. 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. Elsevier. 169-170: 17–23. doi:10.1016/j.quaint.2006.12.017.
  3. FALCONER, H. (1868): Paleontological Memoirs. Volume II: 74 –75; London (Hardwicke).
  4. 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
  5. FRICK, C. (1933): New Remains of Trilophodont-Tetralophodont mastodons. – Bulletin American Museum of Natural History, 59: 505 – 652.
  6. OSBORN, H. F. (1923): New subfamily, generic and specific stages in the evolution of the proboscidea. – American Museum Novitates, 99: 1– 4.
  7. 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).
  8. OLSEN, S. J. (1957): A new beak-jawed mastodont from Florida. – Journal of the Palaeontological Society of India, 2: 131–135.
  9. Mothé, Dimila; Ferretti, Marco P.; Avilla, Leonardo S. (12 January 2016). "The Dance of Tusks: Rediscovery of Lower Incisors in the Pan-American Proboscidean Cuvieronius hyodon Revises Incisor Evolution in Elephantimorpha". PLOS ONE. 11 (1): e0147009. doi:10.1371/journal.pone.0147009. PMC 4710528. PMID 26756209.
  10. LUCAS, 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.
  11. 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.
  12. "OPINION 2295 (Case 3515) Rhynchotherium Falconer, 1868 (Mammalia; Proboscidea): usage conserved by designation of Rhynchotherium falconeri Osborn, 1923 as the type species". March 2012.


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