OTHER ARTHROPODS
Most other arthropods have left poor fossil records because their skeletons are not well mineralized. The most notable exception are the Crustacea -- crabs and their relatives. An example of a fossil crab from Middle Eocene rocks near El Fashn, Egypt is shown below. Though abraded and partly lost, most of the carpace and one claw are visible. The scale bar is 1cm. (Photo by B. Carter.)
The other group of crustacean fossils that is actually quite common as fossils is the Ostracoda. They have been described as "little shrimps in clam shells". Most are around a millimeter in length, though rarely they can reach a couple of centimeters. The shells are calcite and easily preserved and recognized. The photo below shows an example from the Eocene of Alabama. It is a little less than 1mm long.
