Anapsid
| Anapsids Temporal range: Carboniferous - Recent |
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| Anapsid skull | |
Scientific classification  |
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| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Subclass: | Anapsida Williston, 1917 |
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†Captorhinida |
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An anapsid is an amniote whose skull does not have openings near the temples.[1]
While "anapsid reptiles" or "anapsida" were traditionally spoken of as if they were a monophyletic group, it has been suggested that several groups of reptiles that had anapsid skulls may be only distantly related. Scientists still debate the exact relationship between the basal (original) reptiles which first appeared in the late Carboniferous, the various Permian reptiles which had anapsid skulls, and the Testudines (turtles, tortoises, and terrapins). However, it was later suggested the anapsid-like turtle skull may be due to reversion rather than to anapsid descent. The majority of modern paleontologists believe the Testudines are descended from diapsid reptiles which lost their temporal fenestrae. More recent morphological phylogenetic studies with this in mind placed turtles firmly within diapsids[2][3][4], some place turtles as a sister group to extant archosaurs[5][6] or, more commonly within Lepidosauromorpha.[7][8][9][10][11] Some modern paleontologists still believe that Testudines are the only surviving branch of this ancient evolutionary grade, which includes groups such as procolophonids, millerettids, and pareiasaurs,[12] although that view is not generally accepted.
All molecular studies have strongly upheld the placement of turtles within diapsids; some place turtles within Archosauria,[13] or, more commonly, as a sister group to extant archosaurs.[14][15][16][17] However, the most recent molecular study, published in 23 February 2012, suggests that turtles are lepidosauromorph diapsids, most closely related to the lepidosaurs (lizards, snakes, and tuataras).[18] Reanalysis of prior phylogenies suggests they classified turtles as anapsids both because they assumed this classification (most of them studying what sort of anapsid turtles are) and because they did not sample fossil and extant taxa broadly enough for constructing the cladogram. Testudines were suggested to have diverged from other diapsids between 200 and 279 million years ago, though the debate is far from settled.[7][14][19] Most of the other reptiles with anapsid skulls, including the millerettids, nycteroleterids, and pareiasaurs, became extinct in the late Permian period by the Permian-Triassic extinction event. But the procolophonids managed to survive into the Triassic.
[edit] See also
[edit] References
- ^ Pough, F. H. et al. (2002) Vertebrate Life, 6th Ed. Prentice Hall Inc., Upper Saddle River, NJ. ISBN 0130412481
- ^ deBraga, M. and Rieppel, O. (1997). "Reptile phylogeny and the interrelationships of turtles." Zoological Journal of the Linnean Society, 120: 281-354.
- ^ Linda A. Tsuji and Johannes Muller (2009). "Assembling the history of the Parareptilia: phylogeny, diversification, and a new definition of the clade". Fossil Record 12 (1): 71–81. doi:10.1002/mmng.200800011. http://onlinelibrary.wiley.com/doi/10.1002/mmng.200800011/abstract.
- ^ Marcello Ruta, Juan C. Cisneros, Torsten Liebrect, Linda A. Tsuji and Johannes Muller (2011). "Amniotes through major biological crises: faunal turnover among Parareptiles and the end-Permian mass extinction". Palaeontology 54 (5): 1117–1137. doi:10.1111/j.1475-4983.2011.01051.x. http://onlinelibrary.wiley.com/doi/10.1111/j.1475-4983.2011.01051.x/abstract.
- ^ Susan E. Evans (2009). "An early kuehneosaurid reptile (Reptilia: Diapsida) from the Early Triassic of Poland". Paleontologica Polonica 65: 145–178. http://palaeontologia.pan.pl/PP65/PP65_145-178.pdf..
- ^ Magdalena Borsuk−Białynicka; and Susan E. Evans (2009). "A long−necked archosauromorph from the Early Triassic of Poland". Paleontologica Polonica 65: 203–234. http://palaeontologia.pan.pl/PP65/PP65_203-234.pdf.
- ^ a b Rieppel O, DeBraga M (1996). "Turtles as diapsid reptiles". Nature 384 (6608): 453–5. doi:10.1038/384453a0.
- ^ Li, Chun; Xiao-Chun Wu, Olivier Rieppel, Li-Ting Wang & Li-Jun Zhao (2008-11-27). "An ancestral turtle from the Late Triassic of southwestern China". Nature 456 (7221): 497–501. doi:10.1038/nature07533. PMID 19037315.
- ^ Constanze Bickelmann, Johannes Müller and Robert R. Reisz (2009). "The enigmatic diapsid Acerosodontosaurus piveteaui (Reptilia: Neodiapsida) from the Upper Permian of Madagascar and the paraphyly of ‘‘younginiform’’ reptiles". Canadian Journal of Earth Sciences 49: 651–661. doi:10.1139/E09-038.
- ^ Robert R. Reisz, Sean P. Modesto and Diane M. Scott (2011). "A new Early Permian reptile and its significance in early diapsid evolution". Proceedings of the Royal Society B in press. doi:10.1098/rspb.2011.0439. http://rspb.royalsocietypublishing.org/content/early/2011/04/27/rspb.2011.0439.abstract.
- ^ Li, Chun; Olivier Rieppel, Xiao-Chun Wu, Li-Jun Zhao and Li-Ting Wang (2011). "A new Triassic marine reptile from southwestern China". Journal of Vertebrate Paleontology 31 (2): 303–312. doi:10.1080/02724634.2011.550368. http://www.informaworld.com/smpp/content~db=all~content=a935220992~frm=titlelink.
- ^ Jalil, N.-E. and Janvier, P. (2005). "Les pareiasaures (Amniota, Parareptilia) du Permien supérieur du Bassin d’Argana, Maroc." Geodiversitas, 27(1) : 35-132.
- ^ Mannena, Hideyuki; Li, Steven S. -L. (Oct. 1999). "Molecular evidence for a clade of turtles". Molecular Phylogenetics and Evolution 13 (1): 144–148. doi:10.1006/mpev.1999.0640. PMID 10508547.
- ^ a b Zardoya, R.; Meyer, A. (1998). "Complete mitochondrial genome suggests diapsid affinities of turtles". Proc Natl Acad Sci U S A 95 (24): 14226–14231. doi:10.1073/pnas.95.24.14226. ISSN 0027-8424. PMC 24355. PMID 9826682. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=24355.
- ^ Iwabe, N.; Hara, Y.; Kumazawa, Y.; Shibamoto, K.; Saito, Y.; Miyata, T.; Katoh, K. (2004-12-29). "Sister group relationship of turtles to the bird-crocodilian clade revealed by nuclear DNA-coded proteins". Molecular Biology and Evolution 22 (4): 810–813. doi:10.1093/molbev/msi075. PMID 15625185. http://mbe.oxfordjournals.org/content/22/4/810.long. Retrieved 2010-12-31.
- ^ Roos, Jonas; Aggarwal, Ramesh K.; Janke, Axel (Nov. 2007). "Extended mitogenomic phylogenetic analyses yield new insight into crocodylian evolution and their survival of the Cretaceous–Tertiary boundary". Molecular Phylogenetics and Evolution 45 (2): 663–673. doi:10.1016/j.ympev.2007.06.018. PMID 17719245.
- ^ Katsu, Y.; Braun, E. L.; Guillette, L. J. Jr.; Iguchi, T. (2010-03-17). "From reptilian phylogenomics to reptilian genomes: analyses of c-Jun and DJ-1 proto-oncogenes". Cytogenetic and Genome Research 127 (2–4): 79–93. doi:10.1159/000297715. PMID 20234127.
- ^ Tyler R. Lyson, Erik A. Sperling, Alysha M. Heimberg, Jacques A. Gauthier, Benjamin L. King and Kevin J. Peterson. "MicroRNAs support a turtle + lizard clade". Biology Letters 8 (1): 104-107. doi:10.1098/rsbl.2011.0477. http://rsbl.royalsocietypublishing.org/content/8/1/104.
- ^ Benton, M. J. (2000). Vertebrate Paleontology (2nd ed.). London: Blackwell Science Ltd. ISBN 0632056142., 3rd ed. 2004 ISBN 0-632-05637-1
[edit] External links
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Wikispecies has information related to: Anapsida |
- Introduction to Anapsida from UCMP
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