Sweetognathus

Sweetognathus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	†Conodonta
Order:	†Ozarkodinida
Family:	†Sweetognathidae
Genus:	†Sweetognathus Clark, 1972[1]
Species
†Sweetognathus asymmetrica †Sweetognathus expansus †Sweetognathus merrelli †Sweetognathus subsymmetricus †Sweetognathus whitei

Sweetognathus is an extinct genus of conodonts in the family Sweetognathidae that evolved at the beginning of the Permian period (298.9 Ma), in near-equatorial, shallow-water seas.^[2]

The genus is characterized by pustulose ornamentation on a wide, flat-topped carina. It originated in the earliest Permian as S. expansus from Diplognathodus edentulus.^[3]

Sweetognathus forms a species complex.^[4]

The genus is named after paleontologist Walter C. Sweet.

It has been found that recurrent parallel species pairs have occurred throughout Sweetognathus evolution between populations originating in Bolivia, the Mid-Western Unitied States, and Russia.^[2] Parallelisms have been found to occur in the denticle morphologies of their platform elements.^[2]

Use in stratigraphy

According to the List of Global Boundary Stratotype Sections and Points, the species Sweetognathus whitei made its first appearance during the Artinskian (some 290.1 ± 0.26 mya), in the Permian of the Ural Mountains.
The species Sweetognathus merrelli is near first appearance during the Sakmarian (some 295.0 ± 0.18 mya) in the Permian of Kondurovsky, Orenburg, Russia.^[5]

References

1. Early Permian crisis and its bearing on Permo-Triassic conodont taxonomy. DL Clark, Geologica et Palaeontologica, 1972
2. Petryshen, W.; Henderson, C. M.; De Baets, K.; Jarochowska, E. (2020-11-25). "Evidence of parallel evolution in the dental elements of Sweetognathus conodonts". Proceedings of the Royal Society B: Biological Sciences. 287 (1939): 20201922. doi:10.1098/rspb.2020.1922. PMC 7739493. PMID 33203328.
3. Evolution and distribution of the conodonts Sweetognathus and Iranognathus and related genera during the Permian, and their implications for climate change. S Mei, CM Henderson, BR Wardlaw - Palaeogeography, Palaeoclimatology, 2002
4. The Sweetognathus complex in the Permian of China: implications for evolution and homeomorphy. W Cheng-Yuan, SM Ritter… - Journal of Paleontology, 1987
5. Proposal for the base of the Sakmarian Stage: GSSP in the Kondurovsky Section, southern Urals, Russia. BI Chuvashov, VV Chernykh, EY Leven, VI Davydov, Permophiles, 2002

External links

• "Sweetognathus". Paleobiology Database. Retrieved 5 June 2016.