Sweetognathus

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]

Sweetognathus
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
†Conodonta
(unranked):
†Prioniodontida
Order:
†Ozarkodinida
Family:
†Sweetognathidae
Genus:
†Sweetognathus

Clark, 1972[1]
Species
  • †Sweetognathus asymmetrica
  • †Sweetognathus expansus
  • †Sweetognathus merrelli
  • †Sweetognathus subsymmetricus
  • †Sweetognathus whitei

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


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