Large pet lizard
Walking through the bush one incredibly hot afternoon, I heard a rustling sound near a pile of rocks. Now, being someone who has to investigate such noises (the last time I did that I caught a 4-foot-banded snouted cobra!), I eventually spooked this large black lizard out of hiding, only to watch it dart beneath another huge boulder. After much grunting and groaning, and almost dropping the boulder on my leg as the lizard shot out, I did eventually manage to catch it.
Unfortunately, as I grabbed it, it shed its tail, but nonetheless, it was a fine male specimen of good size. And, just as I remember with the pair I’d kept all those years ago, it wriggled like a magician trying to escape from a straightjacket, and proceeded to spray me with the foul contents of its cloaca. Nice to make your acquaintance again!
All in the Family
The family Gerrhosauridae encompasses six known genera. Four of these occur in sub-Saharan Africa and make up the subfamily Gerrhosaurinae: Angolosaurus skoogi, Cordylosaurus subtessellatus, Gerrhosaurus (of which there are six species: Gerrhosaurus flavigularis, G. major, G. multilineatus, G. nigrolineatus, G. typicus and G. validus) and Tetradactylus (of which there are six species: Tetradactylus africanus, T. breyeri, T. eastwoodi, T. ellenbergeri, T. seps and T. tetradactylus). Two further genera, Tracheloptychus and Zonosaurus, are restricted solely to Madagascar, and they make up the subfamily Zonosaurinae. They include: Tracheloptychus madagascariensis, T. petersi, Zonosaurus aeneus, Z. anelanelang, Z. bemaraha, Z. boettgeri, Z. brygooi, Z. flavescens, Z. haraldmeieri, Z. karsteni, Z. laticaudatus, Z. madagascariensis, Z. maramaintso, Z. maximus, Z. ornatus, Z. quadrilineatus, Z. rufipes, Z. subunicolor, Z. Trilineatus and Z. tsingy.
Gerrhosaurus validus is a terrestrial lizard that seldom ventures far from a pile of rocks or clump of thorny bushes.
Trace their ancestry back, and it appears that the family almost certainly evolved as one before Madagascar split from the African continent during the Cretaceous period, 145 to 65 million years ago. This is how the two Madagascan genera then evolved independently.
Because of their similarity in appearance, Gerrhosauridae was initially classified as a subfamily of Cordylidae, but a taxonomic review elevated it to full species status.
Of Gerrhosaurus validus, two subspecies are recognized. The first is the nominate race G. v. validus (the species illustrating this article). This species can be distinguished by the presence of 14 to 16 ventral scale rows, and 18 to 24 lamellae on the fourth toe. The dorsal scales number 28 to 44 longitudinal rows, with 52 to 55 transverse rows. The femoral pores number 18 to 25 in both sexes. The subocular scale (a scale beneath the eye) does not make contact with the lip. Its range is quite broad, extending from Maputaland through to Zambia.