Arcticoceras
Encyclopedia
Arcticoceras is an extinct ammonoid cephalopod genus from the late Middle Jurassic
Middle Jurassic
The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from 176-161 million years ago. In European lithostratigraphy, rocks of this Middle Jurassic age are called the Dogger....

 belonging to the ammonite family Cardioceratidae, more commonly found to high northern latitudes.

The Arcticoceras shell is involute, inner whorls sharply ribbed, outer ones becoming smooth. The suture, following the description of the Sephanocerataceae, is complex, ammonitic, with a dominant 1st lateral lobe and well-developed umbilical lobe. May be derived from Arctocephalites
Arctocephalites
Arctocephalites is an extinct ammonitic cephalopod genus from the Middle Jurassic with a wide northern distribution belonging to the stephanoceratacean family, Cardioceratidae....

.

Arcticoceras is found in northern Alaska, arctic Canada, Greenland, northern and central Russia, as well as in Wyoming, North Dakota, and Utah. Part of the fauna that lived in high latitude (arctic and subarctic) marine waters during the second half of the Middle Jurassic.

Arcticoceras kochi and A ishmanae have been found in the boreal Bathonian stage of central East Greenland . Arcticoceras and Arctocephalites are found the Volga River Basin, Sartov Region, and Arctocephalites in the Pechora River Basin indicating an earlier and deeper penetration of arctic water into European Russia than previously thought.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK