Named By: Jennifer A.Clack - 2002.
Classification: Chordata, Tetrapoda, Amphibia, Whatcheeridae.
Species: P. finneyae.
Size: 1 meter long.
Known locations: Scotland, Ballagan Formation.
Time period: Tournasian of the Carboniferous.
Fossil representation: Articulated skeleton with tail, some parts of the skull and limbs missing.
misidentified as a lobe finned fish, Pederpes is
a very important
entry into the fossil record as it represents the first tetrapod to
evolve to a primarily terrestrial (land based) lifestyle. It also
slots into a barren area of the fossil record referred to as Romer’s
gap, an area where the transition between aquatic and terrestrial
tetrapods was thought to take place but could not be proven until the
discovery of Pederpes.
The feet on Pederpes point forward and not to the side as in earlier tetrapods, an adaptation much more efficient to walking on land. The skull is narrow and suggests that it filled its lungs by muscular action as opposed to a throat pouch.
Despite these terrestrial adaptations, the ear is structured in a way that would enable it to work best when underwater; implying that Pederpes would have least spent some time in the water.