_Hesperoherpeton garnettense_ Peabody (1958), based on a
scapulocoracoid and part of a vertebra, was originally placed in the
order Anthracosauria, suborder Embolomeri, family Cricotidae. A new
skeleton from the type locality near Garnett, Kansas (Rock Lake shale,
Stanton formation, Upper Pennsylvanian), shows that the animal has the
following rhipidistian characters: Large notochordal canal below
foramen magnum, otico-occipital block separate from ethmosphenoid,
postaxial processes on three axial bones of forelimb, pectoral girdle
(probably) articulated with tabular. Nevertheless, _Hesperoherpeton_
has short digits, an anthracosaurian type of pectoral girdle, an otic
rather than spiracular notch, nostrils separate from the mouth, and
vertebrae in which the intercentrum is U-shaped and the pleurocentra
large but paired. The stapes reaches the quadrate.
_Hesperoherpeton_ is placed in a new order, PLESIOPODA, on the basis of
the characters stated above, and a new family, HESPEROHERPETONIDAE.
Specialized characters of the family include: Reduction of
circumorbital bones, bringing the squamosal to the edge of the orbit,
loss of certain bones of the temporal region, and relative enlargement
of the orbits and foramen magnum, in correlation with the diminutive
size of the animal. The structural characters of _Hesperoherpeton_
suggest to us that it lived in the shallow, weedy margins of lagoons,
rested with its head partly out of water, and normally did not walk on
land.