Back Eutheria Afrikaans Eutheria AN ثدييات حقيقية Arabic Euteriyalar Azerbaijani وتریا AZB Eutheria Breton Eutheria BS Euteris Catalan Eutheria CEB Ευθήρια Greek
| Eutheria Temporal range:
| |
|---|---|
.png)
| |
| Skeleton of Microtherulum, a basal eutherian from the Early Cretaceous of China | |
| |
| Northern treeshrew (Tupaia belangeri), a placental eutherian from Southeast Asia | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Subclass: | Theria |
| Clade: | Eutheria Gill, 1872 |
| Subgroups | |
|
see text. | |
Eutheria (from Greek εὐ-, eú- 'good, right' and θηρίον, thēríon 'beast'; lit. 'true beasts'), also called Pan-Placentalia, is the clade consisting of placental mammals and all therian mammals that are more closely related to placentals than to marsupials.
Eutherians are distinguished from noneutherians by various phenotypic traits of the feet, ankles, jaws and teeth. All extant eutherians lack epipubic bones, which are present in all other living mammals (marsupials and monotremes). This allows for expansion of the abdomen during pregnancy,[1] though epipubic bones are present in some primitive eutherians.[2] Eutheria was named in 1872 by Theodore Gill; in 1880, Thomas Henry Huxley defined it to encompass a more broadly defined group than Placentalia.[3]
The oldest known unambiguous eutherians are Durlstodon and Durlstotherium from the Berriasian age of the Early Cretaceous in southern England.[4][5] A possible eutherian species Juramaia sinensis has been dated at 161 million years ago from the early Late Jurassic (Oxfordian) of China.[6] However, Sweetman et al. (2017) considered Juramaia as a stem therian instead,[4] and the Late Jurassic dating has been questioned, with King and Beck (2020) suggesting that Juramaia may originate from Early Cretaceous based on tip-dating analyses, which would make it contemporaneous to several other known eutherians.[7]
- ^ Reilly, Stephen M.; White, Thomas D. (2003-01-17). "Hypaxial Motor Patterns and the Function of Epipubic Bones in Primitive Mammals". Science. 299 (5605): 400–402. Bibcode:2003Sci...299..400R. doi:10.1126/science.1074905. ISSN 0036-8075. PMID 12532019.
- ^ Guilhon, Gabby; Braga, Caryne; Milne, Nick; Cerqueira, Rui (November 2021). "Musculoskeletal anatomy and nomenclature of the mammalian epipubic bones". Journal of Anatomy. 239 (5): 1096–1103. doi:10.1111/joa.13489. ISSN 0021-8782. PMC 8546510. PMID 34195985.
- ^ Archibald, J David. Eutheria (Placental Mammals) (PDF). San Diego, California: San Diego State University.
- ^ a b Sweetman, S.C.; Smith, G.; Martill, D.M. (2017). "Highly derived eutherian mammals from the earliest Cretaceous of southern Britain". Acta Palaeontologica Polonica. 62 (4): 657–665. doi:10.4202/app.00408.2017.
- ^ Martin, T. A.; Averianov, A. O.; Schultz, J. A.; Schwermann, A. H. (2023). "A stem therian mammal from the Lower Cretaceous of Germany". Journal of Vertebrate Paleontology. 42 (6). e2224848. doi:10.1080/02724634.2023.2224848. S2CID 260265765.
- ^ Luo, Z.; C. Yuan; Q. Meng; Q. Ji (2011). "A Jurassic eutherian mammal and divergence of marsupials and placentals". Nature. 476 (7361): 42–45. Bibcode:2011Natur.476..442L. doi:10.1038/nature10291. PMID 21866158.
- ^ King, Benedict; Beck, Robin M. D. (2020-06-10). "Tip dating supports novel resolutions of controversial relationships among early mammals". Proceedings of the Royal Society B: Biological Sciences. 287 (1928): 20200943. doi:10.1098/rspb.2020.0943. ISSN 0962-8452. PMC 7341916. PMID 32517606.
© MMXXIII Rich X Search. We shall prevail. All rights reserved. Rich X Search