Mongolepidida

The Mongolepidida is an order of primitive sharks that lived during the Late Silurian and Early Devonian periods of Russia and Mongolia, with possible fragmentary remains dating back to the Katian epoch of the Late Ordovician (c.450 Ma).[1] The three known genera are: Elegestolepis,[2] Mongolepis[3] and Polymerolepis.[4][1][5][6] They are only known from fragmentary placoid scales, so their appearance is unknown. The oldest of these scales have been dated back to the Ludlow epoch (427.4 Ma to 423 Ma), making the members of the Mongolepidida the oldest sharks known to date.[7]

Mongolepidida
Temporal range: Late Silurian-Early Devonian, 427.4–416 Ma
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Chondrichthyes
Subclass:
Elasmobranchii
Order:
†Mongolepidida

Karatajute-Talimaa et al., 1990
Genera
  • †Elegestolepis Karatajute-Talimaa 1973
  • †Mongolepis Karatajute-Talimaa et al., 1990
  • †Polymerolepis Karatajute-Talimaa, 1968

Although the placoid scales of the Mongolepidida are accepted to be those of sharks, subtle differences in the scales suggest that they may have been quite different in appearance to modern sharks. It is not known what they looked like due to the fragmentary nature of the known remains.[8]

References
  1. Andreev, Plamen; Coates, Michael I.; Karatajūtė-Talimaa, Valentina; Shelton, Richard M.; Cooper, Paul R.; Wang, Nian-Zhong; Sansom, Ivan J. (2016). "The systematics of the Mongolepidida (Chondrichthyes) and the Ordovician origins of the clade". PeerJ. 4: e1850. doi:10.7717/peerj.1850. PMC 4918221. PMID 27350896.
  2. "Elestegolepis". www.planetsharkdivers.com.
  3. "Mongolepis". www.planetsharkdivers.com.
  4. "Polymerolepis". www.planetsharkdivers.com.
  5. Karatajùtè-Talimaa, Valentina (1995-01-01). "The Mongolepidida: Scale structure and systematic position". Geobios. Premiers Vertandébrandés et Vertandébrandés Infandérieurs. ScienceDirect. 28: 35–37. doi:10.1016/S0016-6995(95)80083-2. Retrieved 2020-08-14.
  6. Andreev, Plamen; Zhao, Wenjin; Wang, Nian-Zhong; Meredith Smith, Moya; Li, Qiang; Cui, Xindong; Zhu, Min; Sansom, Ivan (2020-02-13). "Early Silurian chondrichthyans from the Tarim Basin (Xinjiang, China)". PLOS ONE. 15 (2): e0228589. doi:10.1371/journal.pone.0228589. PMC 7018067. PMID 32053606. Retrieved 2020-08-14.
  7. "The Paleobiology Database". paleobiodb.org. Retrieved 2016-05-05.
  8. https://sharkopedia.discovery.com/shark-topics/prehistoric-sharks/#interactive-timeline-of-shark-evolution


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