Fossil seed – Carpolithus sp.
Early Eocene Green River Fm.- Parachute Creek Mbr.
Douglas Pass, CO USA.

7mm fruit on 33mm slab.

Carpolithus is a form genus of a seed or fruit not known to be associated with a particular plant.

The Early Eocene was the warmest interval of the Cenozoic Era.  It was a time when alligators and palm trees were living in the tropical wilds of Wyoming and points north to Ellesmere Island.  During the Middle Eocene climates shifted slightly cooler and drier and trended that way to the point that ice began forming at the poles by the end of the epoch – something that had not happened since the Permian Period.  The Green River Formation was deposited within a couple of million years of the start of the cooling trend.