Gerrhosaurus nigrolineatus, the black-lined plated lizard, is widely distributed in dry rocky semi-open habitats in central to southern Africa. It is relatively easy to tame and therefore popular in the pet trade, which is where the specimen featured here originated.
Gerrhosaurus is a member of Scleroglossa (see also Varanus, Lanthanotus), one of the two major squamate clades (the other being Iguania, e.g., Ctenosaura, Phrynosoma). Within Scleroglossa, Gerrhosaurus resides in Gerrhosauridae (see also Gerrhosaurus major and Tracheloptychus petersi), the hypothesized sister taxon to Cordylidae. Gerrhosauridae is diagnosed, in part, by the following (from Lang, 1991): nasal and prefrontal bones in broad contact; palatine and jugal bones in contact or overlap at the infraorbital foramen; postfrontal not forked medially; supratemporal fenestra entirely closed by postfrontal and squamosal; median posterior processes of parietal bone deeply forked bracing the supraoccipital ridge; skull darkly pigmented; and pterygoid teeth present.
The cranial osteoderms in this group have long hampered the study of their cranial bones, and it is difficult to remove the osteoderms that actually coossify with the dorsal cranial bones without damaging the skull. CT scanning makes it possible to digitally erase the osteoderms and render the skull without them.
About the Species
This frozen specimen originated in the pet trade and no locality information is available. It was made available to the University of Texas High-Resolution X-ray CT Facility for scanning by Dr. Jessie Maisano of The University of Texas and Dr. Jacques Gauthier of Yale University. Funding for scanning and image processing was provided by an NSF grant (DEB-0132227) to Dr. Jack Sites of Brigham Young University.
Lateral view of the scanned specimen.
Dorsal view of the scanned specimen.
About this Specimen
The specimen was scanned by Matthew Colbert on 15 November 2002 along the coronal axis for a total of 600 slices, each slice 0.0633 mm thick with an interslice spacing of 0.0633 mm.
, containing over 1100 citations on cordylids and gerrhosaurids
Estes, R. 1983. Sauria terrestria, Amphisbaenia. Handbuch der Paläoherpetologie, Part 10A. Gustav Fischer Verlag, Stuttgart, 249 pp.
Estes, R., K. de Queiroz, and J. Gauthier. 1988. Phylogenetic relationships within Squamata; pp. 119-281 in R. Estes, and G. Pregill (eds.), Phylogenetic Relationships of the Lizard Families. Stanford University Press, Stanford, California.
Lang, M. 1991. Generic relationships within Coryliformes (Reptilia: Squamata). Bulletin de L'Institut Royal des Sciences Naturelles de Belgique Biologie 61:121-188.
Malan, M. E. 1941. Cranial anatomy of the genus Gerrhosaurus. South African Journal of Science 37:192-217.
A care sheet for plated lizards