Eugeneodontida

From Infogalactic: the planetary knowledge core
(Redirected from Eugeneodontiformes)
Jump to: navigation, search
Eugeneodontida
Temporal range: 360–199.6 Ma
Early Carboniferous to Early Jurassic
Helicoprion bessonovi1DB.jpg
Helicoprion bessonovi
Scientific classification
Kingdom:
Phylum:
Class:
Subclass:
Order:
Eugeneodontida

Zangerl, 1981
Superfamilies and Families

see text

Synonyms
  • Eugeneodontiformes[1]

Lua error in Module:Taxonbar/candidate at line 22: attempt to index field 'wikibase' (a nil value).

Eugeneodontida is an extinct and poorly known order of bizarre cartilaginous fishes. They possessed a unique "tooth-whorl" on the symphysis of the lower jaw as well as pectoral fins supported by long radials. The palatoquadrate was either fused to the skull or reduced. Now determined to be within Holocephali, their closest living relatives are ratfish.[2] The meaning of the name Eugeneodont correlates to "true origin teeth", and comes from the Greek words eu (good/true), geneos(race, kind, origin) and odon (tooth.)

Members of Eugeneodontida are further classified into different families, the most well-preserved members that have been discovered are commonly placed within the families Helicoprionidae ("Spiral Saws"), and Edestidae ("Those which Devour"), the former containing the genera Helicoprion, Sarcoprion and Parahelicoprion, and the latter containing the genera Edestus, Listracanthus and Metaxyacanthus. All eugeneodonts are thought to be obligate carnivores, with each genera having specialized feeding behaviors, territory ranges and specific prey.

Taxonomy

New Discoveries

In 2013, a group of paleontologists discovered the true arrangement of Helicoprion's toothwhorl.[3]

In the same year, 2 specimens of an as yet undescribed species of Helicoprion were discovered. The first specimen suggests an animal that reached 10 meters in length, while the second specimen, nicknamed "Bois", suggests an animal that exceed 12 meters. This suggests that this species of Helicoprion is the largest known eugeneodont.[4]

References

External links


<templatestyles src="Asbox/styles.css"></templatestyles>