Epitheria
| Epitheria Temporal range: Late Cretaceous - Recent
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Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Clade: | Eutheria |
| Infraclass: | Placentalia |
| Clade: | Epitheria |
| Orders and Clades | |
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Epitherians comprise all the
mammals except the Xenarthra. They are primarily characterized by having a stirrup-shaped stapes in the middle ear, which allows for passage of a blood vessel. This is in contrast to the column-shaped stapes found in marsupials, monotremes, and xenarthrans. They are also characterized by having a shorter fibula relative to the tibia
.
Epitheria like Xenarthra and Afrotheria originated after the K-Pg boundary 66 million years ago, with the placental diversification occurring within the first hundred thousand years after the K-Pg event and the first modern placental orders began appearing 2–3 million years later.[1] Epitheres are one of the most successful groups of animals.
presence/absence data) supported the Epitheria clade,[3] more extensive analysis of such transposable element insertions around the time of the divergence of Xenarthra, Afrotheria, and Boreoeutheria strongly support the hypothesis of a near-concomitant origin (trifurcation) of these three superorders of mammals.[4][5]
Another analysis suggests that the root of this clade lies between the Atlantogenata and Boreoeutheria.[6]
Alternative hypotheses
Alternative hypotheses place either
Notolegia
) at the base of the tree:
One Bayesian analysis places the root between Atlantogenata and Boreoeutheria.[7]
References
External links
- Gross, Liza (2006). "Resolving the Family Tree of Placental Mammals". PLOS Biology. 4 (4): e111. PMID 20076552.
- Waddell, P. J.; Kishino, H.; Ota, R. (2001). "A phylogenetic foundation for comparative mammalian genomics". Genome Informatics. 12: 141–154. PMID 11791233. Archived from the originalon 2010-04-23.
- Springer, Mark S.; Murphy, William J.; Eizirik, Eduardo; O'Brien, Stephen J. (2003). "Placental mammal diversification and the Cretaceous–Tertiary boundary". Proceedings of the National Academy of Sciences. 100 (3): 1056–1061. PMID 12552136.
- Wildman, Derek E.; Chen, Caoyi; Erez, Offer; Grossman, Lawrence I.; Goodman, Morris; Romero, Roberto (2006). "Evolution of the mammalian placenta revealed by phylogenetic analysis". Proceedings of the National Academy of Sciences. 103 (9): 3203–3208. PMID 16492730.
- Nikolaev, Sergey; Montoya-Burgos, Juan I.; Margulies, Elliott H.; Program, Nisc Comparative Sequencing; Rougemont, Jacques; Nyffeler, Bruno; Antonarakis, Stylianos E. (2007). "Early History of Mammals is Elucidated with the ENCODE Multiple Species Sequencing Data". PLOS Genetics. 3 (1): e2. S2CID 1982092.
- Churakov, Gennady; Kriegs, Jan Ole; Baertsch, Robert; Zemann, Anja; Brosius, Jürgen; Schmitz, Jürgen (2009). "Mosaic retroposon insertion patterns in placental mammals". Genome Research. 19 (5): 868–875. PMID 19261842.