The Emsian is one of three

faunal stage In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by conven ...

s in the

Early Devonian The Early Devonian is the first of three Epoch (geology), epochs comprising the Devonian period, corresponding to the Lower Devonian Series (stratigraphy), series. It lasted from and began with the Lochkovian Stage , which was followed by the Pr ...

Epoch. It lasted from 410.62 ±1.95 million years ago to 393.47 ±0.99 million years ago. It was preceded by the

Pragian The Pragian is one of three faunal stages in the Early Devonian Epoch. It lasted from 410.8 ± 2.8 million years ago to 407.6 ± 2.8 million years ago. It was preceded by the Lochkovian Stage and followed by the Emsian Stage. The most important ...

Stage and followed by the

Eifelian The Eifelian is the first of two faunal stages in the Middle Devonian Epoch. It lasted from 393.3 ± 1.2 million years ago to 387.7 ± 0.8 million years ago. It was preceded by the Emsian Stage and followed by the Givetian Stage. North American ...

Stage. It is named after the

Ems river The Ems ( ; ) is a river in northwestern Germany. It runs through the states of North Rhine-Westphalia and Lower Saxony, and discharges into the Dollart Bay which is part of the Wadden Sea. Its total length is . The state border between th ...

in Germany. The GSSP is located in the Zinzil'ban Gorge in the

Kitab State Geological Reserve Kitab State Geological Reserve is located in the Kitab district of Kashkadarya region, Uzbekistan. It is located on the south-western branches of the Zarafshan mountain range, on the left bank of the Jinni Darya and on the northern side of Kar ...

Uzbekistan , image_flag = Flag of Uzbekistan.svg , image_coat = Emblem of Uzbekistan.svg , symbol_type = Emblem of Uzbekistan, Emblem , national_anthem = "State Anthem of Uzbekistan, State Anthem of the Republ ...

, above the contact with the Madmon Formation. In North America the Emsian Stage is represented by Sawkill or Sawkillian time.

Biological events

During this period, earliest known agoniatitid

ammonoid Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

fossils began appearing within this stage after first appearing in previous stage and began to evolutionarily radiate within this stage, in which a new ammonoid order

Goniatitida Goniatids, informally goniatites, are ammonoid cephalopods that form the order Goniatitida, derived from the more primitive Agoniatitida during the Middle Devonian some 390 million years ago (around Eifelian stage). Goniatites (goniatitids) su ...

rises in the end of Zlichovian stage (Siberian representation; corresponds to early Eifelian and after the end of Early Devonian, before 391.9 mya). Later agoniatitid ammonoids would die out in the

Taghanic event The Taghanic event (Taghanic unconformity, Taghanic crisis or Taghanic onlap) was an extinction event that occurred about 386 million years ago during the Givetian faunal stage of the Middle Devonian geologic period in the Paleozoic era. It was c ...

in the upper middle

Givetian The Givetian is one of two faunal stages in the Middle Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Eifelian Stage and followed by the Frasnian Stage. It is named after the town of Givet in ...

. Goniatite ammonoids would give rise to further ammonoid orders, thus starting ammonoid dominance of marine fossils in further periods until their end at the Cretaceous-Paleogene mass extinction event.

References

Early Devonian {{geochronology-stub