carboniferous

Of a geologic period within the Paleozoic era; comprises the lower, middle and upper Mississippian and lower, middle and upper Pennsylvanian epochs from about 345 to 280 million years ago, when coal was laid down.

The earliest ink sacs appear in the fossil record in the Carboniferous period around 330 million years ago in cephalopods such as Donovaniconus, Gordoniconus and Saundersites which show a mix of features from older and more modern groups and are placed in their own order, Donovaniconida (Doguzhaeva 2012).

The Carboniferous period.

Containing or producing carbon.