Georgenthalia clavinasica, a new genus and species of amphibamid dissorophoid temnospondyl, is represented
by a small, complete, postmetamorphic skull from the Lower Permian Bromacker locality, Germany. It is only
the third non-amniote of an assemblage of 12 terrestrial tetrapod taxa known from this locality. It is characterized by a
broadly rounded skull with large orbits, a short postorbital length, and a unique keyhole-shaped external naris superficially
resembling that of trematopid dissorophoids. New features that help to discriminate between amphibamid species
are highlighted. Phylogenetically informative characters present in G. clavinasica include: anterolateral flaring of the
lateral margin of frontals; narrow interorbital width; ventral orbital process of the prefrontal contacts palatine; palatine
exposed on lateral surface of ventral rim of orbit; large otic notches closely approach the orbits; absence of a supratympanic
flange of otic notch; long supratympanic process of squamosal with flange-like process that underlaps the midcentral
portion of supratemporal. Several features support a highly terrestrial habitus of G. clavinasica, which is consistent with
the interpretation of the fossiliferous beds of the Bromacker quarry as representing an upland terrestrial environment in
which limnic conditions were characterized by ephemeral lakes and ponds.
A new clade, Olsoniformes, is named for Dissorophidae and Trematopidae (dissorophoids exclusive of Amphibamidae),
and new phylogenetic definitions for Amphibamidae, Trematopidae, and Dissorophidae are presented. The small
neotenic Micromelerpetontidae, and presumably also the neotenic and larval Branchiosauridae, fall within the newly
defined clade Amphibamidae in the current study, and future work should focus on clarifying the nature of this relationship.