SPHENOPHRYNE - American Museum of Natural History
SPHENOPHRYNE - American Museum of Natural History
SPHENOPHRYNE - American Museum of Natural History
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104 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 253<br />
Fig. 61. Changes <strong>of</strong> proportions relative to body size in five species: 1, Oxydactyla stenodactyla; 2,<br />
Austrochaperina derongo; 3,Sphenophryne cornuta; 4,Liophryne schlaginhaufeni; 5,Austrochaperina<br />
palmipes.<br />
<strong>of</strong> teeth or presence <strong>of</strong> serrations would be<br />
apomorphies, possibly either sequential or<br />
independent.<br />
VOMER: This is a complex bone that may<br />
derive from vomerine and palatine precursors,<br />
but whose developmental history remains<br />
to be clarified (Trueb, 1973; de Sá and<br />
Trueb, 1991). I use the term vomer without<br />
prejudice as to the bone’s true nature. In most<br />
species studied (including three Australian<br />
species not illustrated here, but see Zweifel:<br />
1985b, fig. 47), a lateral arm <strong>of</strong> bone extends<br />
from the midline <strong>of</strong> the palate to the maxilla<br />
(or almost so), and an anterior arm passes<br />
medial to the internal naris, in most instances<br />
sending a branch laterally along the anterior<br />
border <strong>of</strong> the naris (fig. 65). The exceptional<br />
species is Austrochaperina novaebritanniae<br />
(fig. 65J), in which there are separate anterior<br />
and posterior bones, and the lateral arm stops<br />
short <strong>of</strong> the maxilla. This may represent a<br />
pedomorphic state. In Sphenophryne cornuta<br />
the lateral arm also tapers out short <strong>of</strong> the<br />
maxillary shelf while the prenasal branch is