Ventastega and Pederpes

Pederpes finneyae (Clack 2002; Tournasian, early Carboniferous, 348mya; 1m in est. length) was an early tetrapod and the first to have only five toes. Here it nests between Koliops and Whatcheeria in the Ichthyostega clade.

Distinct from sister taxa, the skull was taller and not as long. The ribs were shorter. The narrow skull suggests that Pederpes breathed by inhaling with a muscular action like most modern tetrapods, rather than by pumping air into the lungs with a throat pouch the way many modern amphibians do.

Ventastega curonica (Ahlberg et al. 2008 Frasnian, Late Devonian ~365 mya; ~1m length, 20 cm skull) was derived from a sister to Ichthyostega and was basal to Pederpes and Whatcheeria. Although limbs were not found, the pectoral and pelvic girdles are those of limbed tetrapods. The maxilla was probably convex to match the dorsally concave mandile and, based on the scale bars,the skull might have been slightly shorter than the mandibles.

Ahlberg PE, Clack JA, Erv?ns L, Blom H andand Zupi?š I 2008. Ventastega curonica and the origin of tetrapod morphology. Nature. 453 (7199): 1199–1204.

Clack JA 2002. An early tetrapod from 'Romer's Gap'. Nature. 418 (6893): 72–76.

wiki/Pederpes
wiki/Ventastega

Paratetrapoda

Tetrapoda