Relationships of lacertid lizards were assessed on the basis of 84 primary and 112 binary characters drawn mainly from morphology, including features of the skeleton, external anatomy, various internal soft part systems and two aspects of behaviour. Among features not previously used, or not fully investigated before, are structure of the septomaxilla and nasal passages, arranged of the xiphisternal cartilages, mite pockets, kidney position, ulnar nerve arragement, thoracic fascia, aspects of the hemipenis and its associated muscles, female genitalia and jaw muscles. On the basis of parsimony analysis and compatibilty treatment of this character set, the Lacertidae fall into two main portions: A paraphyletic Palaearctic and Oriental group of primitive forms, from which is derived a holophyletic assemblage of Ethiopian and advanced Saharan and Eurasian taxa.
The former group ist not fully resolvable, but Psammodromus and Gallotia appear to be sister groups and are probably related to Lacerta parva and L. fraasi and then L. brandtii, Podarcis appears to be related successively to L. andreanszkyi, the sister species L. dugesii and L. perspicillata, and perhaps L. danfordi and L. laevis. This assemblage may be related to archaeolacertas and Algyroides. The separation of Lacerta lepida, L. pater and L. princeps from the agilis group, based on chemical evidence, is weakly contradicted by morphology. Takydromus may be most closely related to L. vivipara, and L. jayakari and L. cyanura constitute the most likely sister group of the Ethiopian and advanced Saharo-Eurasian assemblage.
Taxe in the Ethiopian and advanced SaharoEuroasian assemblage form a long essentially pectinate tree with relatively change between the side branches, except for a strong disjunction separating the more primitive from the more advanced taxa. Most of the former fall on two main branches, with ´Lacerta` australis and ´L.` rupicola possibly basal to them. 1. the Equatorial forest group containing Gastropholis, Bedriagaia, ´Lacerta` echinata, Adolfus, ´Lacerta` jacksoni and Holaspis. The first three of these constitute a holophyletic group and the same is probably true of the remainder. 2. Tropidosaura, Poromera and Nucras, the latter being the sister group of the more advanced forms. These include successively the Ethiopian Philochortus, Latastia, Ichnotropis and Heliobolus, Pseuderemias, Meroles and Aporosaura, and Pedioplanis, and then the Saharo-Eurasian Eremias, Acanthodactylus, Mesalina and Ophisops-Cabrita.
It seems probable that the ancestors of modern Lacertidae arose in western Eurasia, where the family is known since the Palaeocene and is still represented there largely by quite primitive forms (89 species and seven nominal genera). The family later invaded Africa, perhaps first in the early or middle Miocene. Relatively primitive lacertids spread widely in largely mesic situations in the Ethiopian region, radiating to some extent (six present genera and 16 species) and producing Nucras and the related series of advaned groups (eight genera and 54 species) whoich show increasing adaptation to xeric environments. These genera tend to have heir most primitive species in the northeast and north of the Ethiopian region. The most advaned gave rise to the Saharo-Eurasian clade, now made up to Eremias, Acanthodactylus, Mesalina and Ophisops-Cabrita. This invaded the arid areas of North Africa and Eurasia, where it is presently represented by 70 species. Many morphological changes in increasingly advanced lacertids may be functionally related to the problems of survival in arid, hot, open environments. Considerable ecological parallelism exists in lacertids, with members of separate stocks occupying similar niches in different geographical areas. Morphological adaptations associated with these niches contribute significantly to the high levels of character homoplasy found in the family. There is also some correlation between the degree of niche differentiation in various groups and the quality of the phylogenies that can be produced from their physical characters. A number of morphological parallels exist between advaned lacertids and New World macroteiids. In the skull at least, advaned lacertids show a complex mixture of paedomorphosis and acceleration.
Nomenclatorial changes are as follows: Cabrita is synonymised with Ophisops, necessitating a new name, Ophisops nictans, for Cabrita jerdonii. Aporosaura is synonymised with Meroles, Platyplacopus with Takydromus, and Bedriagaia with Gastropholis. ´Lacerta` (or Centromastyx) echinata is also transferred to the latter genus and Lacerta jacksoni to Adolfus. ´Lacerta` australis and ´L.` rupicola are put in a new genus, Australolacerta. It is recommended that Lacerta dugesii and L. perspicillata should not be placed in the otherwise very uniform genus Podarcis. Although clearly paraphyletic, Lacerta s. lat. Should be retained at least for the present and, if necessary putative relationships within it indicated by informal groups or subgenera.