Anomodont
The Anomodontia were a major group of therapsids, an extinct group of animals commonly known as "mammal-like reptiles." They were mostly toothless herbivores. During the Middle Permian they were very diverse, including groups like the Venyukovioidea, the Dromasauria, the Dicynodontia, and early very primitive forms like Anomocephalus and Patranomodon. Of these only the Dicynodonts survived to the Late Permian, and became the most successful and abundant of all Permian herbivores, filling ecological niches ranging from large browsers down to small burrowers. Only two dicynodont families survived the Permian–Triassic extinction event, one of which, the Lystrosauridae, soon gave rise to the Kannemeyeridae. These latter were large, stocky, beaked animals that remained the dominant terrestrial herbivore right up until the Late Triassic, when changing conditions (perhaps increasing aridity) caused them to decline and eventually die out.
In March 2011, scientists in Brazil discovered the 260-million-year-old fossils of a unique saber-tooth vegetarian. The mammal-like reptile, with the scientific name Tiarajudens eccentricus, used two large fangs at the front of its mouth for shredding and tearing and also probably to ward off predators, but not to eat meat.[1] The fossils are from the extinct Anomodontia suborder within the Therapsida order, four-footed species who dominated during the Permian period, before the dinosaur age.[2] The fossil remains indicate that the snout-nosed creature was slightly larger than the size of a wild boar.
Classification
Taxonomy
Phylogeny
Cladogram modified from Liu et al. (2009):[3]
Below is a cladogram from Kammerer et al. (2011):[4]
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1 Anomodontia, 2 Venyukovioidea, 3 Chainosauria, 4 Dicynodontia, 5 Therochelonia, 6 Diictodontia, 7 Pylaecephalidae, 8 Emydopoidea, 9 Kistecephalia, 10 Kingoriidae, 11 Cistecephalidae, 12 Bidentalia |
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See also
References
- ^ NYTimes.com. “Fearsome Fangs, for a Plant-Eater.” Bhando. March 25, 2011.
- ^ NationalGeographic.com: “Odd Saber-Toothed Beast Discovered—Preyed on ... Plants?” Handwerk. March 24, 2011.
- ^ Liu, J.; Rubidge, B.; and Li, J. (2009). "A new specimen of Biseridens qilianicus indicates its phylogenetic position as the most basal anomodont". Proceedings of the Royal Society B 277 (1679): 285–292. doi:10.1098/rspb.2009.0883. PMC 2842672. PMID 19640887. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2842672.
- ^ Kammerer, C.F.; Angielczyk, K.D.; and Fröbisch, J. (2011). "A comprehensive taxonomic revision of Dicynodon (Therapsida, Anomodontia) and its implications for dicynodont phylogeny, biogeography, and biostratigraphy". Journal of Vertebrate Paleontology 31 (Suppl. 1): 1-158. doi:10.1080/02724634.2011.627074.
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Basal therapsids |
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Eutherapsida |
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Related categories |
Synapsids · Therapsids
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Anomodonts
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Early anomodonts
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Basal anomodonts
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Anomocephaloidea
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Shansiodontidae
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Other kannemeyeriforms
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Related categories
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Anomodonts · Dicynodonts
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