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
Subphylum:	Vertebrata
Infraphylum:	Agnatha
Class:	†Conodonta
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.

Recurrent parallel species pairs have occurred throughout Sweetognathus evolution between populations originating in Bolivia, the Midwestern United 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]