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Lissodus is an extinct genus of hybodont. While fossils attributed to this genus are known spanning from the latest Devonian (Famennian) to the very end of the Cretaceous (Maastrichtian),[2] others consider the genus to have a more narrow range, spanning from the Early Triassic to the end of the Early Cretaceous (Albian).[3] Lissodus is often placed in the family Lonchidiidae, though other authors consider it incertae sedis within Hybodontiformes. Lonchidion has often been regarded as synonymous, but many recent authors consider it to be a distinct but closely related genus.[3]

Lissodus
Temporal range: Early Carboniferous–Albian
Teeth of Lissodus hasleensis
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Hybodontiformes
Family: Lonchidiidae
Genus: Lissodus
Brough, 1935
Type species

Lissodus africanus Broom, 1909[1]

Description

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Lissodus sensu lato (including Lonchidion) has been estimated to have had a body size range of 15–50 centimetres (0.49–1.64 ft).[2] Typical dental features of this genus include a single central cusp, base of teeth expanding towards the lingual side and riddled with vascular canals.[1] The shape of the main cusp and large canal openings are similar to those of the Cassisodus margaritae although latter has cusplets on both sides of the crown.[1] The low crowned teeth suggest that Lissodus was a bottom dweller that fed by crushing hard shelled organisms (durophagy).[2]

Distribution

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Remains of Lissodus sensu lato have been found worldwide in both marine and freshwater environments.[2]

One tooth of indeterminate Lissodus species is known from the Tournaisian Laurel Formation, Australia.[1]

Preserved skull and postcranial remains are known for the Early Triassic species L. cassangensis and L. africanus from Angola and South Africa respectively.[3]

Species

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Known species:[4]

  • Lissodus africanus
  • Lissodus angulatus
  • Lissodus bartheli
  • Lissodus cassangensis
  • Lissodus cristatus
  • Lissodus guenneguesi
  • Lissodus hasleensis
  • Lissodus johnsonorum
  • Lissodus leiodus
  • Lissodus leiopleurus
  • Lissodus lepagei
  • Lissodus levis
  • Lissodus minimus
  • Lissodus wardi
  • Lissodus xiushuiensis

References

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  1. ^ a b c d Brett Roelofs, Milo Barham, Arthur J. Mory, Kate Trinajstics (January 2016). "Late Devonian and Early Carboniferous chondrichthyans from the Fairfield Group, Canning Basin, Western Australia". Palaeontologia Electronica. 19 (1): 1–28. doi:10.26879/583.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  2. ^ a b c d J. Fischer Brief synopsis of the hybodont form taxon Lissodus Brough, 1935, with remarks on the environment and associated fauna Freiberger Forschungshefte Serie C, 528 (2008), pp. 1-23
  3. ^ a b c Jan Rees & Charlie J. Underwood (2002). "The status of the shark genus Lissodus Brough, 1935, and the position of nominal Lissodus species within the Hybodontoidea (Selachii)" (PDF). Journal of Vertebrate Paleontology. 22 (3): 471–479. doi:10.1671/0272-4634(2002)022[0471:tsotsg]2.0.co;2. JSTOR 4524243. S2CID 13836075.
  4. ^ "PBDB". paleobiodb.org. Retrieved 2024-01-22.