''Sweetognathus'' is an extinct genus of
conodont
Conodonts, are an extinct group of marine jawless vertebrates belonging to the class Conodonta (from Ancient Greek κῶνος (''kōnos''), meaning " cone", and ὀδούς (''odoús''), meaning "tooth"). They are primarily known from their hard ...
s in the family
Sweetognathidae that evolved at the beginning of the Permian period (298.9 Ma), in near-equatorial, shallow-water seas.
The genus is characterized by pustulose ornamentation on a wide, flat-topped carina. It originated in the earliest
Permian
The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...
as ''S. expansus'' from ''
Diplognathodus edentulus''. ''Sweetognathus'' forms a species complex. The genus is named after paleontologist
Walter C. Sweet.
Recurrent parallel species pairs have occurred throughout ''Sweetognathus'' evolution between populations originating in
Bolivia
Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...
, the
Midwestern United States
The Midwestern United States (also referred to as the Midwest, the Heartland or the American Midwest) is one of the four census regions defined by the United States Census Bureau. It occupies the northern central part of the United States. It ...
, and
Russia
Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...
.
Parallelisms have been found to occur in the denticle morphologies of their platform elements.
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 Ural Mountains ( ),; , ; , or simply the Urals, are a mountain range in Eurasia that runs north–south mostly through Russia, from the coast of the Arctic Ocean to the river Ural (river), Ural and northwestern Kazakhstan. .
The species ''Sweetognathus merrelli'' is near first appearance during the
Sakmarian (some 295.0 ± 0.18 mya) in the Permian of
Kondurovsky,
Orenburg, Russia.
[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]
References
External links
*
Ozarkodinida genera
{{Conodont-stub