back to comparative morphology Ancient frogs Hyloides branches Hylids part I Bufonids part I Bufonids part II   Rana sylvatica Wood frog family: Ranidae Polypodates leucomystax Common treefrog of Southeast Asia family: Rhacophoridae

Gastrophryne carolinensis Eastern narrow-mouth toad family: Microhylidae

Kassina senegalensis Striped running frog family: Hyperoliidae

The Ranoides limb immediately splits into two lines: the Allodapanura and the Natatanura. Here are APs from two frogs in each line. The rhacophorids and the ranids are situated at or near the end of the Natatanura line, and thus are presumed to be recently-derived species (i.e., among the newest of the new frogs and toads). The microhylids are situated at the base of the Allodapanura line, and thus are presumed to be among the oldest members of that line. The hyperoliids, on the other hand, are situated at the end of the Allodapanura line and thus presumed to be among the most recently derived members of the line. In this small sampling of Ranoides, in the most recently derived animals we see very long caudal extensions, with large proportions of the total AP hair-cell populations. Interesting questions arise when one contrasts these caudal extensions with those of the bufonids, which are situated near the end of the Hyloides limb.

Although the tectorial corner is not labelled on the image of the wood frog AP, it is easy to locate. In that image there is a conspicuous ridge running along the nerve branch. In the center of the micrograph it overhangs the lateral edge of the papilla, then curves upward to the left. The ridge is the locus of attachment of the tectorial curtain, its intesection with the papilla is the location of the tectorial corner. The location of the tectorial curtain (in all neobatrachians) will take on added significance as we begin to combine the comparative morphology with comparative physiology.