''Eosemionotus'' ("dawn ''

Semionotus ''Semionotus'' (from , 'mark' and , 'back') is an extinct genus of ray-finned fish found throughout Northern Pangaea (North America and Europe) during the late Triassic, becoming extinct in the Early Jurassic The Jurassic ( ) is a Geological ...

''") is an extinct genus of prehistoric marine macrosemiid

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

from the

Middle Triassic In the geologic timescale, the Middle Triassic is the second of three epoch (geology), epochs of the Triassic period (geology), period or the middle of three series (stratigraphy), series in which the Triassic system (stratigraphy), system is di ...

(

Anisian In the geologic timescale, the Anisian is the lower stage (stratigraphy), stage or earliest geologic age, age of the Middle Triassic series (stratigraphy), series or geologic epoch, epoch and lasted from million years ago until million years ag ...

Ladinian The Ladinian is a stage and age in the Middle Triassic series or epoch. It spans the time between Ma and ~237 Ma (million years ago). The Ladinian was preceded by the Anisian and succeeded by the Carnian (part of the Upper or Late Triassic ...

). It was a speciose genus known from throughout Europe, including formations of the

Muschelkalk The Muschelkalk (German for "shell-bearing limestone"; ) is a sequence of sedimentary rock, sedimentary rock strata (a lithostratigraphy, lithostratigraphic unit) in the geology of central and western Europe. It has a Middle Triassic (240 to 230 m ...

. The following species are known: * ''E. ceresiensis'' Bürgin, 2004 - early

of Italy (

Besano Formation The Besano Formation is a geological formation in the southern Alps of northwestern Italy and southern Switzerland. This formation, a thin but fossiliferous succession of Dolomite (rock), dolomite and Shale, black shale, is famous for its preserva ...

) * ''E. diskosomus'' López-Arbarello ''et al.'', 2019 - early Ladinian of Italy ( Meride Formation) and Switzerland ( Cassina Formation) * ''E. minutus'' López-Arbarello ''et al.'', 2019 - early Ladinian of Italy (Meride Formation) * ''E. ratumensis'' Diependaal ''et al.'' 2024 - mid-late

of the Netherlands ( Vossenveld Formation) * ''E. sceltrichensis'' López-Arbarello ''et al.'', 2019 - Ladinian of Switzerland (Meride Formation) * ''E. vogeli'' ( von Fritsch, 1906) - late Anisian of Germany ( Heilbronn Formation) (='' Allolepidotus vogeli'' von Fritsch, 1906) In addition, indeterminate remains of ''Eosemionotus'' are known from Spain, Slovenia, and China. The

Tethys Ocean The Tethys Ocean ( ; ), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean during much of the Mesozoic Era and early-mid Cenozoic Era. It was the predecessor to the modern Indian Ocean, the Mediterranean Sea, and the Eurasia ...

appears to have been the center of diversification for the genus. The species ''E. vogeli'' appears to descend from a population that dispersed from the Tethys into the

Germanic Basin The Germanic Basin () is a large region of sedimentation in Western and Central Europe that, during the Permian and Triassic periods, extended from England in the west to the eastern border of Poland in the east. To the south it is bounded by the ...

prior to the late Anisian.

References

Prehistoric ray-finned fish genera {{Triassic-fish-stub Macrosemiiformes Anisian genus first appearances Ladinian genus extinctions Middle Triassic fish Triassic fish of Europe Fossils of Italy Fossils of Switzerland Fossils of Germany Fossils of the Netherlands Fossils of Spain Fossils of Slovenia Fossils of China Fossil taxa described in 1919

See also

References