Brachyura sp. Sea Crab Crustacea Decapoda Brachyura

Sea Crab Brachyura sp. Crustacea Decapoda Brachyura carapace mm 8-11 (legs and claws not included), not identified specie.

Crabs (Brachyura Linnaeus, 1758) are an infraorder of predominantly aquatic decapod crustaceans.
In particular, crabs are equipped with a robust carapace and two powerful claws, therefore they use four pairs of limbs for movement and claws for catching, defending and feeding. In some species one claw is noticeably larger than the other. The abdomen is folded vertically and is therefore hidden.
The first true fossil brachyurs date back to the Lower Jurassic (Pliensbachian). Fossil crab tracks (Laterigradus lusitanica) have been discovered in the paleontological site of Cabeço da Ladeira (Portugal). These would move the evolution of crabs with amphibious adaptations to the Middle Jurassic (Baiocyan).