Fossil Crab Harpactoca. This is a wonderful specimen with all claws intact.Crab emerging from a matrix. They appear in Middle Jurassic strata of Europe. Over time a remarkable transition took place to preserve the body of this delicate fossil and that its shell was made of chitin that hardened and thickened with limy material. This crab is intact, the claws and jointed body is perfectly detailed and three dimensional.