American Legless Lizards (Anniellidae) have a fossil record going back to the Eocene, but do not appear to have ever been abundant. There are two recognized modern species, neither of which is numerous and both of which have restriced ranges, the California Legless Lizard (Anniella pulchra) is known from southeastern California and northern Baja California, while the Baja California Legless Lizard (Anniella geronimensis) is found only in northern Baja California. All post-Eocene members of the group appear to have lived within the ranges of these modern species.
In a paper published in the journal Breviora on 16 September 2013, Theodore Papenfuss of the Museum of Vertebrate Zoology at the University of California, Berkeley and James Parham of the John D. Cooper Archaeology and Paleontology Center at the Department of Geological Sciences at the California State University describe four new species of American Legless Lizards from California, discovered as a result of a genetic study of the California Legless Lizard. Three of these species are distinguishable from the California Legless Lizard by physical examination, but the fourth is considered to be entirely cryptic (i.e. indistinguishable from another species), detectable only by genetic analysis but nevertheless likely to be reproductively isolated.
The first new species described is given the name Anniella alexanderae, in honour of the Californian naturalist Annie Montague Alexander (1867–1950), or the Temblor Legless Lizard. The species has a distinctive light grey belly which distinguishes it from other members of the genus. It is described from a number of specimens collected from underneath cover boards and flattened cardboard boxes placed on sandy soil along the Shale Road in Kern County, California.
Anniella alexanderae in dorsal (left) and ventral (right) views. Papenfuss & Parham (2013).
The environment at Shale Road in Kern County, in which Anniella alexanderae was found living. Papenfuss & Parham (2013).
The second new species is named Anniella campi, in honour of Charles Lewis Camp (1893–1974), a former director of the University of California Museum of Paleontology, or the Southern Sierra Legless Lizard. This species shows a unique pattern of dark stripes running lengthways along the body, which was found in all examined specimens and no specimens of any other species, as determined by genetic analysis. The species is known from three localities on the edge of the Mojave Desert in Kern and Inyo counties.
Anniella campi in dorsal view, with enlarged view of the head. Papenfuss & Parham (2013).
The environment at Big Spring in Kern County, in which Anniella campi was found living. Papenfuss & Parham (2013).
The third new species is named Anniella grinnelli, in honour of Joseph Grinnell (1877–1939), the first
director of the Museum of Vertebrate Zoology at the University of California at Berkeley, or the Bakersfield Legless Lizard. This species has a greyish-red coloured belly, not seen in other members of the genus. The species is found in the southern San Joaquin Valley and eastern Carrizo Plain, including within the city of Bakersfield.
Anniella grinnelli in dorsal (top) and ventral (bottom) views. Papenfuss & Parham (2013).
The environment at Memorial Nature Trail in the Sand Ridge Preserve in Kern County, in which Anniella grinnelli was found living. Papenfuss & Parham (2013).
The final new species is named Anniella stebbinsi, in honour of Robert Cyril Stebbins (1915–), the first Curator of Herpetology at the Museum of Vertebrate Zoology, or the Southern California Legless Lizard. This is a true cryptic species indistinguishable from the California Legless Lizard (Anniella pulchra) without genetic analysis. The species is found from the western margin of the Colorado Desert to the coast of California, and may be found elsewhere.
Anniella stebbinsi in dorsal (top) and ventral (bottom) views. Papenfuss & Parham (2013).
The environment at El Segundo Dunes at Los Angeles International Airport, in which Anniella stebbinsi was found living. Papenfuss & Parham (2013).
The California Legless Lizard was already considered to be a species of special concern, under the classification system used by the California Department of Fish and Wildlife, due to its low population numbers and restricted range. The division of the species into five separate species believed reproductively isolated therefore has profound implications for the conservation of the Lizards, each species of which has a considerably lower population and more restricted range than formerly ascribed to the single species. In addition two of the new species Anniella grinnelli and Anniella stebbinsi have parts of their range within areas of active urban development and expansion, with two populations of Anniella grinnelli known to have had their habitat destroyed in Bakersfield in the last decade.
Map showing the revised distribution of the five species of American Legless Lizards within the State of California. Scale bar is 100 km. Papenfuss & Parham (2013).
See also The biodiversity of Beaded Lizards, Two new species of Woodlizard from northeast Peru, A Venomous Lizard from the Late Cretaceous of Mongolia, Three new species of Dragon Lizard from the western arid zone of Australia and Genetic Diversity in Atlas Dwarf Lizards.
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