Abstract

Previously described and new specimens of the anthracosaur Silvanerpeton miripedes
from the Scottish Vise´an of East Kirkton yield important new data which allow us to provide a more
complete reconstruction of the skull roof, palate, braincase and lower jaw. A stout sacral rib and an
incompletely ossified tarsus with a subquadrangular intermedium are also recorded for the first time.
A remarkably well preserved humerus in extensor view shows similarities with humeri of immature
specimens of the embolomere Proterogyrinus. A new cladistic analysis, built from combining
characters used in two recent matrices, places Silvanerpeton in a basal position relative to
embolomeres and more derived stem amniotes. Data from Silvanerpeton inform character polarity
near the base of the amniote total group. We discuss some morphofunctional implications of
character changes at the root of total group amniotes, acquisition of terrestrial habits, and patterns
of early disparity in this clade.