''Mesogondolella'' is an extinct genus of
conodont
Conodonts (Greek ''kōnos'', "cone", + ''odont'', "tooth") are an extinct group of agnathan (jawless) vertebrates resembling eels, classified in the class Conodonta. For many years, they were known only from their tooth-like oral elements, which ...
s.
The species ''M. daheshenensis'' and ''M. subgracilis'' are from the Permian (probably
Wordian
In the geologic timescale, the Wordian is an age or stage of the Permian. It is the middle of three subdivisions of the Guadalupian Epoch or Series. The Wordian lasted between and million years ago (Ma). It was preceded by the Roadian and foll ...
) of the
Daheshen Formation in China.
[The age of the Daheshen Formation in Jilin Province based on conodonts. Xiao-dong Zhou, Dong-jin Li, Guang-qi Wang, Xi-qing Sun and Cheng-yuan Wang, Acta Palaeontologica Sinica, 2013, volume 52, issue 3, pages 294–308]
The top of the
Sakmarian
In the geologic timescale, the Sakmarian is an age or stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Sakmarian lasted between 293.52 and million years ago (Ma). It was preceded by the Asselian and followed by t ...
stage (the base of the
Artinskian
In the geologic timescale, the Artinskian is an age or stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Artinskian likely lasted between and million years ago (Ma) according to the most recent revision of the ...
) is defined as the place in the stratigraphic record where fossils of conodont species ''
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.
The genus is characterized by pustulose ornamentation on a ...
'' and ''Mesogondolella bisselli'' first appear.
References
External links
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Ozarkodinida genera
Permian conodonts
{{Conodont-stub