Prehistroic Models: Echinodermata
Echinodermata means “spiny or hedgehog skin” consist of sea stars, sea urchins, sand dollars, sea cucumbers, and crinoids “sea lillyies”. Most animals have bilateral symmetry, adults echinoderms have pentameral (five-point) symmetry. The earliest members of this group appears during the Cambrian Perion over 500 million years ago.
Domain: Eukarya – Kingdom: Animalia – Phylum: Echinodermata – Superclass: Asterozoa – Class: Asteroidea
(sea stars formally “starfish”)
Triassic to Present
Domain: Eukarya – Kingdom: Animalia – Phylum: Echinodermata – Subphylum: Echinozoa – Class: Holothuroidea
Ordovician to Present