Gnathodus
Appearance
(Redirected from Gnathodus typicus)
Gnathodus Temporal range:
| |
---|---|
![]() | |
Conodont elements from the Deer Valley Member of the Mauch Chunk Formation detail
Figures 3–9. Conodonts from the uppermost Loyalhanna Limestone Member of the Mauch Chunk Formation, Keystone quarry, Pa. This collection (93RS–79b) is from the upper 10 cm of the Loyalhanna Member. Note the highly abraded and reworked aeolian forms. 9. Gnathodus texanus?, Pa element, upper view, X140. Figures 10–14. Conodonts from the basal 20 cm of the Loyalhanna Limestone Member of the Mauch Chunk Formation, Keystone quarry, Pa. (93RS–79a), and Westernport, Md. (93RS–67). Note the highly abraded and reworked aeolian forms. 12. Gnathodus sp., Pa element, upper view, reworked Late Devonian(?) through Mississippian morphotype, 93RS–67, X140. | |
Scientific classification | |
Kingdom: | |
Phylum: | |
Class: | |
Order: | |
Family: | |
Genus: | †Gnathodus |
Species | |
|
Gnathodus is an extinct conodont genus in the family Idiognathodontidae.
Use in stratigraphy
[edit]The Tournaisian, the oldest age of the Mississippian (also known as Lower Carboniferous), contains eight conodont biozones, 3 of which are defined by Gnathodus species:
- the zone of Gnathodus pseudosemiglaber and Scaliognathus anchoralis
- the zone of Gnathodus semiglaber and Polygnathus communis
- the zone of Gnathodus typicus and Siphonodella isosticha
The Visean, the second age of the Mississippian, contains four conodont biozones, two of which are defined by Gnathodus species:
- the Gnathodus bilineatus Zone
- the Gnathodus texanus Zone
The Serpukhovian, the third or youngest age of the Mississippian, includes four conodont biozones, two of which are defined by Gnathodus species:
- the Gnathodus postbilineatus Zone
- the Gnathodus bollandensis Zone
References
[edit]- ^ Monographie der fossilen fische des silurischen systems des Russisch-baltischen gouvernements. CH Pander, 1856
- Proposal of Gnathodus bilineatus (Roundy, 1926) as type species of the genus Gnathodus Pander, 1856 (Conodonts). HR Lane and W Ziegler, Senckenbergiana lethaea, 1984
External links
[edit]- Gnathodus at fossilworks.org (retrieved 15 May 2016)