Toxodontidae

Toxodontidae
Temporal range: Late Oligocene-Holocene (Deseadan-Lujanian)
~27–0.011 Ma
Toxodon platensis
Skeleton of Nesodon imbricatus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Notoungulata
Clade: Eutoxodontia
Family: Toxodontidae
Owen 1845
Subfamilies and genera

Haplodontheriinae

Nesodontinae

Toxodontinae

Xotodon sp. skull at the Museum für Naturkunde, Berlin

Toxodontidae is an extinct family of notoungulate mammals, known from the Oligocene to the Holocene (11,000 BP) of South America,[1] with one genus, Mixotoxodon, also known from the Pleistocene of Central America and southern North America (as far north as Texas).[2] Member of the family were medium to large-sized,[3] ranging from around 350–400 kilograms (770–880 lb) in Nesodon to 1,000–1,200 kilograms (2,200–2,600 lb) in Toxodon,[4] and had medium to high-crowned dentition, which in derived members of the group evolved into ever-growing cheek teeth.[5] Isotopic analyses have led to the conclusion that Pleistocene members of the family were flexible mixed feeders (both browsing and grazing).[6][7]

  1. ^ Turvey, Samuel T. (2009-05-28). Holocene Extinctions. OUP Oxford. ISBN 9780191579981.
  2. ^ E. Lundelius, et al. 2013. The first occurrence of a toxodont (Mammalia, Notoungulata) in the United States. Journal of Vertebrate Paleontology, Vol 33, No 1, pp. 229–232 DOI:10.1080/02724634.2012.711405
  3. ^ Cassini, Guillermo H.; Flores, David A.; Vizcaíno, Sergio F. (July 2012). "Postnatal ontogenetic scaling of Nesodontine (Notoungulata, Toxodontidae) cranial morphology: Nesodontine cranial allometry". Acta Zoologica. 93 (3): 249–259. doi:10.1111/j.1463-6395.2011.00501.x. hdl:11336/81335.
  4. ^ Nelson, Allison; Engelman, Russell K.; Croft, Darin A. (2023-07-12). "How to weigh a fossil mammal? South American notoungulates as a case study for estimating body mass in extinct clades". Journal of Mammalian Evolution. doi:10.1007/s10914-023-09669-1. ISSN 1064-7554.
  5. ^ Gomes Rodrigues, Helder; Herrel, Anthony; Billet, Guillaume (2017-01-31). "Ontogenetic and life history trait changes associated with convergent ecological specializations in extinct ungulate mammals". Proceedings of the National Academy of Sciences. 114 (5): 1069–1074. doi:10.1073/pnas.1614029114. ISSN 0027-8424. PMC 5293108. PMID 28096389.
  6. ^ MacFadden, Bruce J. (September 2005). "Diet and habitat of toxodont megaherbivores (Mammalia, Notoungulata) from the late Quaternary of South and Central America". Quaternary Research. 64 (2): 113–124. Bibcode:2005QuRes..64..113M. doi:10.1016/j.yqres.2005.05.003.
  7. ^ Pérez-Crespo, Víctor Adrián; Arroyo-Cabrales, Joaquín; Guzmán, Ana Fabiola; Morales-Puente, Pedro; Cienfuegos-Alvarado, Edith; Otero, Francisco J. (2020-01-09). "ISOTOPIC PALEOECOLOGY OF A TOXODONT (MIXOTOXODON LARENSIS) FROM MICHOACAN, MEXICO". The Southwestern Naturalist. 64 (1): 63. doi:10.1894/0038-4909-64-1-63. ISSN 0038-4909.