Jamieson, B.G.M. 1995c. The ultrastructure of spermatozoa of the Squamata (Reptilia) with phylogenetic considerations. In Advances in Spermatozoal Phylogeny and Taxonomy. Jamieson, B.G.M., Ausio, J. and Justine, J.-L. eds. pp. 359-383. Mémoires du Muséum national d'Histoire Naturelle, vol. 166, Paris.
Comparative ultrastructure of squamate families is reviewed, with new data for the South African chamaeleon, Bradypodion karroicum. Parsimony analysis is conducted, using Chelonia as the outgroup and branch and bound searching. Two major spermatozoal autapomorphies for the Squamata are extension of the fibrous sheath into the midpiece and (not computed) the paracrystalline subacrosomal cone. Further synapomorphies defining the Squamata sensu strictu are a single perforatorium in place of the two or three of Sphenodontida and Chelonia; loss of the endonuclear canal; presence of sinuous mitochondria (possibly an artefactual parsimony resolution as a columnar form is intuitively preferred); intermitochondrial location of dense bodies (mitochondrial transformations); presence of a well developed epinuclear electron lucent region and, equivocally, arrangement of the dense bodies as periodic rings. A major inference is polyphyly of the 'Sauria', the Scincomorpha and the Scincidae. Sphenomorphus group and egemid skinks show no close relationship to Eugongylus-group skinks which form the sister-group of the pygopodid Lialis. Snakes are the sister-group of the Eugongylus+pygopod clade. Gekkonidae appear to be a relatively plesiomorphic group, separated by several families from the Pygopodidae. The Iguania is not a monophyletic assemblage, iguanids and Pogona occur in the same clade but Pogona appears to be the sister-taxon of Varanus. Another iguanian, the chamaeleon Bradypodion, has an unresolved relationship with the gekkonid+snake+pygopodid+Eugongylus-clade. Sphenomorph and egemid skinks form an unresolved clade with Chalcides and lacertids but linkage of lacertids with the Teiidae in the Lacertoidea is not upheld. Pending further investigations of a larger number of taxa, these results can only be considered heuristic.