The right scapulocoracoid is almost complete, and the left one is
present but partly broken into three pieces, somewhat pushed out of
position. With the advantage of this new material, we may comment on
the scapulocoracoid of _H. garnettense_ as described by Peabody (1958).
In size and contour, the slight differences between the type (KU 9976)
and the new skeleton (KU 10295) are considered to be no more than
individual variation. We have redrawn the type (Fig. 8) in order to
show the resemblances more clearly.
The small sections that were missing from the type are present in KU
10295. The jagged edge directly posterior to the area occupied by the
neural arch in the type extends 0.5 mm. farther back in our specimen.
The angle formed between the recurved dorsal ramus and the edge of the
ventral flange is seen in our specimen to be less than 90 deg.. The glenoid
fossa, appearing as a concave articular surface for the cap of the
humerus, was in part covered by cartilage and shows as "unfinished"
bone (Peabody, 1958, p. 572); this area is more oval than triangular,
as Peabody thought. The obstruction of a clear view of this part of the
type is the result of the accidental position of a neural arch. The
raised portion immediately dorsal to the glenoid fossa exhibits an
unfinished surface, suggesting the presence of either cartilage or a
ligament.
[Illustration: FIG. 8. _Hesperoherpeton garnettense_ Peabody. Type
specimen redrawn. Right scapulocoracoid in external view (at left), and
internal view (at right). KU 9976, x 4.]
[Illustration: FIG. 9. _Hesperoherpeton garnettense_ Peabody. Right
scapulocoracoid in external view, showing part of interclavicle, and
position occupied by clavicle. The specimen is flattened and lies
entirely in one plane. KU 10295, x 4.]
[Illustration: FIG. 10. _Hesperoherpeton garnettense_ Peabody. Right
clavicle in external view. Anterior edge to right. KU 10295, x 4.]
The right clavicle is complete, and resembles a spoon having a slender
handle. The dorsal tip of the handle is L-shaped. The expanded ventral
part is convex externally, and rested upon the anteroventral surface of
the scapulocoracoid. The lateral edge next to the "stem" is distinctly
concave, abruptly becoming similar in contour to the opposite edge, and
giving the impression of an unsymmetrical spoon. The left clavicle is
present in scattered fragments, its dorsal hooklike end being intact.
The posterior end of the interclavicle lies in contact with the right
scapulocoracoid. There are short lateral processes at the point where
the interclavicle was overlapped by the clavicles, but we cannot be
sure of the extent of this bone anteriorly or posteriorly.
The presumed left cleithrum, a long rectangle, is approximately equal
in length to the rodlike stem of the clavicle, and is about as wide as
the dorsal L-shaped tip of the clavicle. The posterior end of the
cleithrum presumably met the tip of the clavicle, while the rest of it
was directed anteriorly and a little dorsally. There seems to be a
small articular surface near the anterior extremity which suggests the
presence of a supracleithrum. The upper border of the cleithrum is
slightly convex and the lower concave.