Triisodontidae

Triisodontidae
Temporal range: Early to Late Paleocene 65.4–57.5 Ma
Skull and jaws of Triisodon quivirensis
Life restoration of Triisodon quivirensis
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Clade: Pan-Euungulata
Family: †Triisodontidae
Scott, 1894
Type genus
†Triisodon
Cope, 1881
Genera

†Eoconodon
†Goniacodon
†Oxyclaenus
†Stelocyon
†Triisodon

Synonyms
  • Triisodontinae Troussart, 1904

Triisodontidae is an extinct paraphyletic family of hoofed mammals that were endemic to North America during the Paleocene. Triisodontids were the first large predatory mammals to appear in North America following the extinction of the non-avian dinosaurs. They differ from mesonychians in having less highly modified dentition.

Their relationship with mesonychians has changed since the discovery of the family. Scott (1894) suggested a close relationship with mesonychids. Some experts would classify triisodontids as mesonychians. It was also hypothesized because of their less derived dentition, they may have considered them to have ancestral to mesonychids. An abstract by Sarah et al. (2015) recovered triisodontids as a paraphyletic group of stem-mesonychians. However, other studies recovered triisodontids to be more closely related to modern ungulates than to mesonychians. Phylogenetic analysis by Solé et al. (2023), suggests mesonychians split off from the lineage leading to triisodontids during the Late Cretaceous.

Taxonomy

Classification

Triisodontidae was first named by Scott (1894) within the order Creodonta, being closely related to mesonychids. Triisodontids were classified as Triisodontinae by Troussart (1904). Matthew (1909) would classify triisodontines as mesonychids within Creodonta, within the suborder Acreodi. However, Matthew (1937) would move triisodontines within Arctocyonidae. Mesonychids and arctocyonids would be moved from Creodonta and into Condylarthra, also known as archaic ungulates by Van Valen (1966). Triisodontines would later be reclassified as a family of mammals, with some studies such as McKenna and Bell (1997) reclassifying them as mesonychians. Within phylogenetic analysis by Tabuce et al. (2011) recovered the family as a basal paraphyletic family within Acreodi. Sarah et al. (2015) recovered triisodontids as a paraphyletic stem-mesonychians within Euungulata. However, other studies classify them more closely related to living ungulates than to mesonychians.

Description

The largest triisodontid genus was Triisodon, with the smallest species weighing between 32–44 kg (71–97 lb).

References

  1. 1 2 3 4 Toosey, William J.; Williamson, Thomas E.; Shelley, Sarah L.; Brusatte, Stephen L. (2024-11-11). "The osteology of Triisodon crassicuspis (Cope, 1882): New insights into the enigmatic "archaic" placental mammal group "Triisodontidae"". PLOS ONE. 19 (11) e0311187. doi:10.1371/journal.pone.0311187. ISSN 1932-6203. PMC 11554371.
  2. 1 2 T. R. Lyson; I. M. Miller; A. D. Bercovici; K. Weissenburger; A. J. Fuentes; W. C. Clyde; J. W. Hagadorn; M. J. Butrim; K. R. Johnson; R. F. Fleming; R. S. Barclay; S. A. Maccracken; B. Lloyd; G. P. Wilson; D. W. Krause; S. G. B. Chester (October 2019). "Exceptional continental record of biotic recovery after the Cretaceous–Paleogene mass extinction". Science. 366 (6468): 977–983. doi:10.1126/science.aay2268. PMID 31649141. S2CID 204883579.
  3. 1 2 3 Rodolphe Tabuce, Julien Clavel and Miguel Telles Antunes (2011). "A structural intermediate between triisodontids and mesonychians (Mammalia, Acreodi) from the earliest Eocene of Portugal". Naturwissenschaften. 98 (2): 145–155. Bibcode:2011NW.....98..145T. doi:10.1007/s00114-010-0747-y. PMID 21181109. S2CID 22526630.
  4. 1 2 3 Sarah L. Shelley, Thomas E. Williamson, Stephen L. Brusatte, Resolving the higher-level phylogenetic relationships of “Triisodontidae” (‘Condylarthra’) within Placentalia, October 2015, Society of Vertebrate Paleontology (abstract)
  5. ↑ Clemens, W.A. & T.E. Williamson (2005). "A new species of Eoconodon (Triisodontidae, Mammalia) from the San Juan Basin, New Mexico". Journal of Vertebrate Paleontology. 25 (1): 208–213. doi:10.1671/0272-4634(2005)025[0208:ANSOET]2.0.CO;2. ISSN 0272-4634. S2CID 86047162.
  6. ↑ T. R. Lyson; I. M. Miller; A. D. Bercovici; K. Weissenburger; A. J. Fuentes; W. C. Clyde; J. W. Hagadorn; M. J. Butrim; K. R. Johnson; R. F. Fleming; R. S. Barclay; S. A. Maccracken; B. Lloyd; G. P. Wilson; D. W. Krause; S. G. B. Chester (October 2019). "Exceptional continental record of biotic recovery after the Cretaceous–Paleogene mass extinction". Science. 366 (6468): 977–983. doi:10.1126/science.aay2268. PMID 31649141. S2CID 204883579.
  7. 1 2 3 Matthew, W.D. (1937). "Paleocene faunas of the San Juan Basin, New Mexico". Transactions of the American Philosophical Society. 30 (3532). American Philosophical Society: 1–510. Bibcode:1937Natur.140...46C. doi:10.2307/1005521. JSTOR 1005521.
  8. 1 2 Scott, W. B. (1894). "A Revision of the North American Creodonta with Notes on Some Genera Which Have Been Referred to That Group". Proceedings of the Academy of Natural Sciences of Philadelphia. 44: 291–323.
  9. 1 2 Osborn, Henry F.; Matthew, William D. (1909). "Cenozoic mammal horizons of western North America, with faunal lists of the Tertiary Mammalia of the West". US Geol Surv Bull. 361: 91–120. doi:10.3133/b361.
  10. 1 2 3 Rose, Kenneth D. (2006). "Cete and Artiodactyla". The beginning of the Age of Mammals. Baltimore: Johns Hopkins University Press. ISBN 978-0-8018-9221-9.
  11. ↑ Szalay, Frederick S. (1969). "Origin and Evolution of Function of the Mesonychid Condylarth Feeding Mechanism". Evolution. 23 (4): 703–720. doi:10.1111/j.1558-5646.1969.tb03552.x. JSTOR 2406864.
  12. 1 2 Yu, Yang; Gao, Hongyan; Li, Qiang; Ni, Xijun (2023-01-01). "A new entelodont (Artiodactyla, Mammalia) from the late Eocene of China and its phylogenetic implications". Journal of Systematic Palaeontology. 21 (1). Bibcode:2023JSPal..2189436Y. doi:10.1080/14772019.2023.2189436. ISSN 1477-2019.
  13. 1 2 Spaulding, Michelle; O'Leary, Maureen A.; Gatesy, John (2009-09-23). "Relationships of Cetacea (Artiodactyla) Among Mammals: Increased Taxon Sampling Alters Interpretations of Key Fossils and Character Evolution". PLOS ONE. 4 (9) e7062. Bibcode:2009PLoSO...4.7062S. doi:10.1371/journal.pone.0007062. ISSN 1932-6203. PMC 2740860. PMID 19774069.
  14. 1 2 Solé, Floréal; Fournier, Morgane; Ladevèze, Sandrine; et al. (2023). "New postcranial elements of mesonychid mammals from the Ypresian of France: New hypotheses for the radiation and evolution of the mesonychids in Europe". Journal of Mammalian Evolution. 30 (2): 371–401. doi:10.1007/s10914-023-09651-x.
  15. ↑ Van Valen, Leigh M. (1966). "Deltatheridia, a new order of mammals". Bulletin of the American Museum of Natural History. 132 (1): 1–126. hdl:2246/1126.
  16. ↑ Szalay, F.S.; Gould, S.J. (1966). "Asiatic Mesonychidae (Mammalia, Condylarthra)". Bulletin of the AMNH. 132 (2): 127–174.