what type of body cavity do reptiles have
1 Coelomate animals or Coelomata (also known as eucoelomates â true coelom) have a fluid filled body cavity called a coelom /ËsiËlÉm/ with a complete lining called peritoneum derived from mesoderm (one of the three primary tissue layers).he space between the parietal layer and the visceral layer is known as the coelom or body cavity. In Deuterostomes, the coelom forms by enterocoely: mesoderm buds from the walls of the archenteron and hollows to become the coelomic cavities.