Southern Alligator Lizard (Elgaria multicarinata) Fact Sheet: Taxonomy & History

• Elgaria multicarinata formerly Gerrhonotus multicarinatus
• Multicarinatus means "many keeled" referring to the ridge down the center of the scales
• The San Diego Alligator Lizard subspecies named in honor of T.H. Webb who participated in the U.S. and Mexican Boundary Survey in the 1850's.
• Many herpetologists today don't recognize subspecies, due to their lack of genetic distinctiveness

• Lizards in the anguid family originated in the northern hemisphere, sometime before 55 million years ago.
  • 102 species and 15 genera in this family (Wiens and Slingluff 2001)
  • Limbless or reduced-limb species have evolved many times in anguids (Wiens and Slingluff)
• Fossils lizards in the sub-family Gerrhonotinae date at least to the early Eocene (50 to 55 million years ago) in North and Central America
• Fossil anguids with strongly keeled scales such as Glyptosaurus are found in Eocene rocks in southern California and elsewhere
• Southern species of the genus Elgaria became distinct from the northern species in the Miocene (around 6.6 million years ago)
• Geographical barriers influenced the evolution of other species of Elgaria, especially (Macey et al 1999)
  • Formation of the Gulf of California
  • Climate change leading to formation of the Mojave desert
  • Uplift of the California coastal mountains
• By about 1.5 million years ago in the Pleistocene, E. multicarinata and E. panamintina became separate species.

Kingdom: Animalia

Phylum: Chordata

Class: Reptilia

Order: Squamata

Family: Anguidae

Genus: Elgaria

Species: Elgaria multicarinata – Southern Alligator Lizard

Subspecies: E. m. webbi (San Diego Alligator Lizard)
Subspecies: E. m. multicarinata (California Alligator Lizard)
Subspecies: E. m. scincicauda (Oregon Alligator Lizard)
Subspecies: E. m. nana (Los Coronados Alligator Lizard)
Subspecies: E. m. ignava (San Martin Alligator Lizard)

Describer and Date: Weigmann 1828 for Elgaria; Blainville 1835 for Elgaria multicarinata; Baird 1858 for E. m. webbi (Proceedings of the Academy of Natural Sciences. Philadelphia 1858: 253-256)

Macey et al (1999)
Wiens and Slingluff (2001)