SPHENOPHRYNE - American Museum of Natural History
SPHENOPHRYNE - American Museum of Natural History
SPHENOPHRYNE - American Museum of Natural History
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100 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 253<br />
Fig. 56. Lower surfaces <strong>of</strong> feet and hands <strong>of</strong> Austrochaperina. A. A. rivularis, AMNH A77576. B.<br />
A. macrorhyncha, BPBM 13860. C. A. basipalmata, AMNH A78167. D. A. palmipes, AMNH A81210.<br />
E. A. parkeri, MCZ A89220. F. A. blumi, MZB 3562. Scale bars marked in 1-mm intervals.<br />
The most striking ontogenetic change in<br />
O. stenodactyla is the relative narrowing <strong>of</strong><br />
the head. Head-first burrowing through tightly<br />
packed grass may put a premium on maintaining<br />
a narrow prow.<br />
Austrochaperina derongo has proportions<br />
that I associate with leaf-litter species, in the<br />
midrange <strong>of</strong> the other species and paralleling<br />
the growth changes <strong>of</strong> most others.<br />
Sphenophryne cornuta is notable for its<br />
ontogenetic increase in relative hand size,<br />
foot length, and disc size. These tendencies<br />
must be related to its scansorial habits. The<br />
increase in foot length coupled with a decrease<br />
in tibia length is especially notable,<br />
for in most species these two are directly correlated<br />
both in trend direction and amount.<br />
Liophryne schlaginhaufeni has the longest<br />
legs and feet, and both measurements increase<br />
relatively with growth, in marked contrast<br />
to the other species (but see cornuta,<br />
above). This elongation <strong>of</strong> limb segments<br />
provides an efficient jumping mechanism in<br />
a surface-active species, and the maintenance<br />
<strong>of</strong> relative eye size rather than relative decrease<br />
may be related to surface activity, too.<br />
The increase in the size <strong>of</strong> the small finger<br />
discs is not explicable as a direct adaptation,<br />
but may merely accompany the significant<br />
increase in hand size.<br />
Increase in hand size is presumably a scansorial<br />
adaptation in A. palmipes, although in<br />
this instance the climbing is done on streamassociated<br />
rocks rather than in bushes. The<br />
digital discs are large and either increase<br />
slightly (fingers) or maintain their relative<br />
size (toes).<br />
OSTEOLOGY<br />
A thorough description <strong>of</strong> the osteology is<br />
not possible owing to lack <strong>of</strong> appropriate material<br />
<strong>of</strong> about 40% <strong>of</strong> the species studied. I<br />
have examined cleared-and-stained (bone, or