Invertebrates Chordata Vertebrates

Subphylum Cephalochordata Urochordata

SubPhylum Cephalochordata Exclusively marine animals ; they are capable of swimming but usually are buried in the sand with only their anterior end being exposed

Garstang's Hypothesis called this process paedomorphosis, a term that describes the presence (or evolutionary retention) of juvenile or larval traits in the adult body

South American Lungfish : a living species of Lepidosiren . look at the four slender "fins" of this fish, which are homologous to the four legs of terrestrial vertebrates. Lung Fishes - Sarcopterygii

An extinct tetrapod genus, among the first vertebrates to have recognizable limbs which appeared in the Upper Devonian about 365 mya, and was anatomically intermediate between lobe-finned fishes and the first tetrapods fully capable of coming onto land.

An early tetrapod that lived in the Upper Devonian period, 367-362.5 mya. It was a labyrinthodont that represents an intermediate form between fish and amphibians. It possessed lungs and limbs that helped it navigate through shallow water in swamps.

Fire salamender - Salamandra salamandra Leaf Green Tree Frog - Litoria phyllochroa Toad - Bufo marinus