Iberolacerta


Iberolacerta is a genus of lizards in the family Lacertidae. The genus contains at least eight described species, which are mainly found in Spain and France. I. horvathi has a wider geographic range, being distributed in Central Europe.

Distribution

The species of Iberolacerta are distinct and mainly found in the western Europe mountain ranges. Iberolacerta species found in Germany could have possibly been caused by human introduction, and are thus controversial. For example, I. horvathi had been encountered in southern Germany, but has not been encountered thereafter.

Morphological features

Lizards of the genus Iberolacerta have certain features in common, including: a depressed head and body; 7–9 premaxillary teeth; ~26 presacral vertebrae ; inscriptional ribs; tail brightly colored in hatchlings.
Some of the lizards in this genus have specific features such as: rostral and frontonasal scales; one postanal scale; supranasal and anterior loreal scales; 36 or fewer macro chromosomes; egg-laid embryos somewhat developed.
Small species are up to approximately in snout-to-vent length. All species have shown to have females that are larger than males.

Skull

The skull contains 7–9 premaxillary teeth, no pterygoid teeth, and a slender nasal process. In addition there is a separation between the frontal bone and the postorbital bone.

Post-cranial skeleton

In species of the genus Iberolacerta the number of presacral vertebrae differs according to sex. Presacral vertebrae in males can range from 25–26, while the presacral vertebrae in the larger females can range from 26–29. Both sexes also have an average of 6 posterior presacral vertebrae with relatively short ribs. The tail vertebrae can have the common A-type pattern or less common B-type pattern.

Coloration

The coloration of the dorsal side contains stripes, bands, and spots near or where the vertebral column is located. The coloration of the ventral side is white, light yellow, deep orange, or green. The tails of juveniles are often bright green or blue.

Chromosome counts

Iberolacerta species contain a diploid number of autosomes ranging from 36 and below. The sex chromosomes come in two different types depending on the number of Z chromosomes that are species specific: ZW-type or Z1Z2W-type. The chromosomes also can contain nucleolar organizer in large macrochromosomes, termed L-type, or in a medium macrochromosome, termed M-type.

Ecology

These lizards tend to be found as solid surface rock dwellers but can be found associated with small loose stones.

Species

Evolution

Speciation theory caused by mountain ranges and Pleistocene glacial cycles: It is believed that many of the Iberolacerta genus had led to many speciation seen today because of the Pleistocene glacial cycles and Holocene habitat fragmentation. For example, I. monticola has been studied to determine its cause of speciation. There was an analysis of 17 I. monticola population's mitochondrial DNA sequences, at a control region and cytochrome b loci, throughout the northwestern quadrant of the Iberian Peninsula. The results these researchers data gathered lead to the conclusion that correlated to a “refugia within refugia” model since the comparative phylogeographic analyses had shown consistent genetic subdivisions patterns. This suggested that the mountain ranges could potentially be the cause of the descending species of Iberolacerta. It was also hypothesized that the Holocene epoch then represented a long-term survival inflexion point for the derived species not to survive the preceding glacial cycle.

Reproduction

During copulation the male bites and latches to the flanks of the females, allowing the fertilization of ~3–10 eggs. In newly laid eggs the embryos are somewhat developed, and range depending on species from ~23 to 36 days until hatching.