Mb. Harvey et Rl. Gutberlet, MICROSTRUCTURE, EVOLUTION, AND ONTOGENY OF SCALE SURFACES IN CORDYLIDAND GERRHOSAURID LIZARDS, Journal of morphology, 226(2), 1995, pp. 121-139
The distal oberhautchen and proximal beta layer of 41 species and ever
y genus of cordylid and gerrhosaurid lizard were examined with a scann
ing electron microscope. Scale organs in these families are concentrat
ed on the face, and scale organs occur singly or in pairs below the ke
el on the dorsals of cordylids but not gerrhosaurids. Most species exa
mined possess primitive, lenticular scale organs. Unique and previousl
y unknown, projecting scale organs occur in two species of Cordylus. S
cale organs appear to be absent in species of Chamaesaura. The scale s
urfaces of cordylids are covered in macrohoneycomb. Individual compart
ments of cordylid macrohoneycomb are not intracellular structures but
may be overlain by apparent oberhautchen cells. In some cordylid speci
es, part of each cell is free and projects away from the scale surface
as a pointed flap. Gerrhosaurids lack macrohoneycomb. Instead, their
scale surfaces are covered in lamellae without dentate borders, 50-100
times as long as wide. The epidermis of Platysaurus is unique among c
ordylids in possessing lamellae 1-8 times as wide as long that overlap
macrohoneycomb in some regions of the body. The scale surfaces of Cor
dylus cordylus undergo an ontogenetic change similar to that recently
described for the xenosaurid genus Shinisaurus. Phylogenetic analysis
of scale surface features allows the partitioning of Cordylus into thr
ee species groups and Chamaesaura into two species groups. Synapomorph
ies of the species of Chamaesaura, the species of Platysaurus, and the
genera of the gerrhosaurids are also described. (C) 1995 Wiley-Liss,
Inc.