Cleithrolepis Explained

Cleithrolepis is an extinct genus of freshwater ray-finned fish that lived from the Induan age (Early Triassic epoch) to the Anisian (Middle Triassic) in what is now Australia (New South Wales, Tasmania) and Libya. A species from Late Triassic Germany, C. brueckneri, was also ascribed to Cleithrolepis.^[1] ^[2]

Taxonomy

The following species are known:

†C. altus Woodward, 1890 - Olenekian (Early Triassic) or Anisian (Middle Triassic) of New South Wales, Australia (Terrigal Formation)
†C. granulatus Egerton, 1864 - Induan (Early Triassic) of Tasmania, Australia (Knocklofty Formation) to Anisian of New South Wales, Australia (Terrigal Formation)^[3]
†C. major Gardiner, 1988 - Anisian of Cyrenaica, Libya (Alma Formation)^[4] ^[5]

Dubious remains are known from the Ladinian of Spain. The dubious species "C." brueckneri Oertle, 1931 from the Carnian of Germany was previously assigned to this genus, although its actual taxonomic status remains uncertain. The former species C. extoni Woodward, 1888 from South Africa has been reclassified into the related genus Cleithrolepidina, while the former species C. cuyana from Argentina has been reclassified into Pseudobeaconia in the Louwoichthyiformes.^[6]

It was formerly placed in the order Perleidiformes, but recent taxonomic revisions have found that order to be non-monophyletic, and it is now placed in the order Polzbergiiformes.^[7]

Appearance

The genus grew to about 30cm (10inches) long. It had a weak lower jaw with teeth only at the tip.^[8]

Occurrence

Cleithrolepis lived in rivers, billabongs and lakes in the large braided river system that deposited the Hawkesbury Sandstone in what is now New South Wales, with fossils found in shale lenses within the sandstone.^[9] Fossils were also found in Tasmania (Knocklofty Formation) and in a drill core sample from Libya, 10840feet below the surface.

External links

Fossil of freshwater fish, Cleithrolepis granulata - Somersby, New South Wales, Middle Triassic, 240 million years ago.

Notes and References

Romano . Carlo . Koot . Martha B. . Kogan . Ilja . Brayard . Arnaud . Minikh . Alla V. . Brinkmann . Winand . Bucher . Hugo . Kriwet . Jürgen . 2016 . Permian-Triassic Osteichthyes (bony fishes): diversity dynamics and body size evolution (supplementary material) . Biological Reviews of the Cambridge Philosophical Society . 91 . 1 . 106–147 . 10.1111/brv.12161 . 1469-185X . 25431138.
Web site: PBDB Taxon . 2024-05-18 . paleobiodb.org.
Dziewa . T. J. . 1980 . Early Triassic osteichthyans from the Knocklofty Formation of Tasmania . Papers and Proceedings of the Royal Society of Tasmania . en . 114 . 145–160 . 10.26749/rstpp.114.145 . 0080-4703.
Book: Gardiner, Brian G. . Brian Gardiner (biologist) . Subsurface palynostratigraphy of northeast Libya . Garyounis University Publications . 1988 . A. El-Arnauti . Benghazi . 259–265 . A new Cleithrolepis from the Triassic of central Cyrenaica, northeast Libya . B. Owens . B. Thusu.
Book: LeBlanc, Jacques . A Guide to Macrofossil Localities of Libya . 2000.
LóPez‐Arbarello . Adriana . Rauhut . Oliver W. M. . CerdeñO . Esperanza . 2010 . The Triassic fish faunas of the Cuyana Basin, Western Argentina . Palaeontology . en . 53 . 2 . 249–276 . 10.1111/j.1475-4983.2010.00931.x . 0031-0239.
Xu . Guang-Hui . 2020-06-19 . A new stem-neopterygian fish from the Middle Triassic (Anisian) of Yunnan, China, with a reassessment of the relationships of early neopterygian clades . Zoological Journal of the Linnean Society . 191 . 2 . 375–394 . 10.1093/zoolinnean/zlaa053 . 0024-4082.
Web site: Freshwater fish, Cleithrolepis granulata - Australian Museum . australianmuseum.net.au . dead . https://web.archive.org/web/20091025175245/http://www.australianmuseum.net.au/image/Freshwater-fish-Cleithrolepis-granulata/ . 2009-10-25.
Web site: Show item . 2009-10-28 . dead . https://web.archive.org/web/20091014210733/http://lrrresources.cli.det.nsw.edu.au/fossils/showItem.aspx?id=52 . 2009-10-14 .