Drepanolepis

Drepanolepis
Reconstruction of Drepanolepis maerssae
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Infraphylum:	Agnatha
Class:	†Thelodonti
Order:	†Furcacaudiformes
Genus:	†Drepanolepis
Species
Drepanolepis maerssae

Drepanolepis is an extinct genus of furcacaudiform thelodont which lived in the Northwest Territories of Canada during the Early Devonian period. It hails from the MOTH locality in the Mackenzie Mountains.^[1]

Description

Drepanolepis possessed a tall, angelfish-like body, with a ventral mouth and a hypocercal tail. The gill atrium is large for this order, and the nasal runs down to the oral cavity from the orbit. The oral cavity is jawless, with no premaxilla or maxilla present.^[2][1]

The scales of Drepanolepis likely served an anti-parasite role, similar to modern sharks which form large groups and cruise at slow to medium speeds.^[3][4]

References

1. Wilson, Mark V. H.; Caldwell, Michael W. (1998-04-10). "The Furcacaudiformes: a new order of jawless vertebrates with thelodont scales, based on articulated Silurian and Devonian fossils from northern Canada". Journal of Vertebrate Paleontology. 18 (1): 10–29. doi:10.1080/02724634.1998.10011031. ISSN 0272-4634. JSTOR 4523870.
2. Wilson, Mark V. H.; Caldwell, Michael W. (1993-02-01). "New Silurian and Devonian fork-tailed 'thelodonts' are jawless vertebrates with stomachs and deep bodies". Nature. 361 (6411): 442–444. Bibcode:1993Natur.361..442W. doi:10.1038/361442a0. ISSN 0028-0836.
3. Ferrón, Humberto G.; Botella, Héctor (2017). "Squamation and ecology of thelodonts". PLOS ONE. 12 (2) e0172781. Bibcode:2017PLoSO..1272781F. doi:10.1371/journal.pone.0172781. PMC 5328365. PMID 28241029.
4. Ferrón, Humberto G; Martínez-Pérez, Carlos; Turner, Susan; Manzanares, Esther; Botella, Héctor (2018). "Patterns of ecological diversification in thelodonts". Palaeontology. 61 (2): 303–315. doi:10.1111/pala.12347. hdl:10550/85568.