Metaxypoda (lit. "in-between feet") are a clade of amphibious Sarcopodia.
Metaxypods are a sister clade of the fully terrestrial Osteopods, first appearing around 4161ma. Having diverged before the evolution of an internal skeleton, Metaxypods cannot support themselves very well out of the water, and therefore remain primarily in marshes and freshwater rivers, where they feed on Myzostoma.
The size comparison charts in Part 7 showed a Metaxypod with a total body length of roughly 0.3 meters.