h 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.
LITERATURE CITED
EATON, T. H., JR.
1951. Origin of tetrapod limbs. Amer. Midl. Nat., 46: 245-251.
JARVIK, E.
1952. On the fish-like tail in the ichthyostegid stegocephalians.
Meddel. om Gronland, 114: 1-90.
1954. On the visceral skeleton in _Eusthenopteron_ with a discussion
of the parasphenoid and palatoquadrate in fishes. Kgl. Svenska
Vetenskapsakad. Handl., 5: 1-104.
1955. The oldest tetrapods and their forerunners. Sci. Monthly,
80: 141-154.
MOORE, R. C., FRYE, J. C., and JEWETT, J. M.
1944. Tabular description of outcropping rocks in Kansas. Kansas
State Geol. Surv. Bull., 52: 137-212.
PEABODY, F. E.
1952. _Petrolacosaurus kansensis_ Lane, a Pennsylvanian reptile
from Kansas. Univ. Kansas Paleont. Contrib., Vertebrata,
Art. 1: 1-41.
1958. An embolomerous amphibian in the Garnett fauna (Pennsylvanian)
of Kansas. Jour. Paleont., 32: 571-573.
ROMER, A. S.
1937. The braincase of the Carboniferous crossopterygian
_Megalichthys nitidus_. Mus. Comp. Zool. Bull., 82: 1-73.
1947. Review of the Labyrinthodontia. Mus. Comp. Zool. Bull.,
99: 1-368.
1957. The appendicular skeleton of the Permian embolomerous
amphibian _Archeria_. Univ. Michigan Contrib. Mus. Paleont.,
13: 103-159.
WATSON, D. M. S.
1926. The evolution and origin of the Amphibia. Phil. Trans. Roy.
Soc. London, (B) 214: 189-257.
_Transmitted January 13, 1960.
|