''Craspedites'' is an ammonoid cephalopod included in the

Perisphinctoidea Perisphinctoidea, formerly Perisphinctaceae, is a superfamily of Middle Jurassic (Bajocian) to Lower Cretaceous (Barremian) Ammonitina, ammonites, commonly with evolute shells with strong ribbing that typically divides about mid flank before cro ...

that lived during the Late

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...

and Early

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

, found in

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordered by Lithuania and Russia to the northeast, Belarus and Ukrai ...

, and the

Russian Federation 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 ...

Diagnosis and range

''Craspedites'', described by Aleksei Petrovich Pavlow in 1892, is characterized by a small, up to about 5 cm in diameter, smooth, essentially involute shell with simple ammonitic sutures. Whorl section is rounded, venter smooth; umbilicus small, exposing the dorsal portion of the inner whorls. Main sutural elements, primary saddles and lobes, are modified by small secondaries. ''Craspedites'' was thought to be restricted to the Upper Jurassic

Tithonian In the geological timescale, the Tithonian is the latest age (geology), age of the Late Jurassic Epoch and the uppermost stage (stratigraphy), stage of the Upper Jurassic Series. It spans the time between 149.2 ±0.7 annum, Ma and 143.1 ±0.6 (mi ...

until discovery of a new species, ''C. sachsi'', described from the

Berriasian In the geological timescale, the Berriasian is an age/ stage of the Early/Lower Cretaceous. It is the oldest subdivision in the entire Cretaceous. It has been taken to span the time between 143.1 ±0.6 Ma and 137.05 ± 0.2 (million years ago) ...

age of

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 ...

by A. E. Igolnikov in 2012, named in honour of

paleontologist Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geolo ...

V.N. Sachs.

Species

*''C. canadensis'' Jeletzky, 1966 *''C. ivanovi'' Gerasimov, 1960 *''C. jugensis'' Prigorovsky, 1906 *''C. kaschpuricus'' *''C. mosquensis'' Gerasimov, 1960 *''C. nodiger'' Eichwald, 1868 *''C. planus'' *''C. praeokensis'' Rogov, 2017 *''C. pseudofragilis'' Gerasimov, 1960 *''C. sachsi'' Igolnikov, 2012 *''C. shulginae'' Alifirov, 2009 *''C. singularis'' *''C. taimyrensis'' *''C. transitionis'' Rogov, 2017 *''C. unshensis''

Diagnosis and range

Species

References

Further reading