Anguidae

(vertebrate zoology) A family of limbless, snakelike lizards in the suborder Sauria, commonly known as slowworms or glass snakes.

(Anguidae)

Class: Reptilia

Order: Squamata

Suborder: Sauria

Family: Anguidae

Thumbnail description
Small to large lizards with elongated bodies; dorsal and ventral scales reinforced by underlying bone (osteoderms); and, in many species, reduced or absent limbs

Size
2.8–55.1 in (70–1,400 mm)

Number of genera, species
14 genera; 112 species

Habitat
Coastal dunes, desert, grasslands, chaparral, pine flatwoods, cloud forest, pine-oak forest, tropical wet forest, and paramo (high-altitude habitat that is cold, wet, and dominated by grasses and shrubs)

Conservation status
Extinct: 1 species; Critically Endangered: 3 species; Endangered: 1 species; Vulnerable: 1 species

Distribution
North, Central, and South America; the Greater and Lesser Antilles; Europe; North Africa; southwestern Asia; and Southeast Asia, including the islands of the Sunda Shelf

Evolution and systematics

The Anguidae is a monophyletic group within the Anguimorpha and is related most closely to either the Varanoidea (Varanidae, Lanthanotidae, and Helodermatidae) or the Xenosauridae and Shinisauridae. The 14 anguid genera are classified among four subfamilies as follows: Anguinae (glass lizards and slowworm—Ophisaurus and Anguis), Anniellinae (legless lizards—Anniella), Diploglossinae (galliwasps and allies—Celestus, Diploglossus, Ophiodes, Sauresia, and Wetmorena), and Gerrhonotinae (alligator lizards—Abronia, Barisia, Coloptychon, Elgaria, Gerrhonotus, and Mesaspis).

Phylogenetic analyses of DNA sequence data strongly support the monophyly of the Anguidae and three of its subfamilies, but monophyly of the Diploglossinae requires further evaluation. These analyses also suggest that the Gerrhonotinae and Anguinae are sister taxa and that the Anniellinae is the most basal subfamily. Within the Anguinae, Ophisaurus is paraphyletic with respect to Anguis; the geographically proximate A. fragilis and O. apodus are sister taxa. Within the Diploglossinae, Sauresia and Wetmorena appear to be sister taxa, and Ophiodes is related closely to the West Indian Diploglossus. Studies with a denser sampling of diploglossine taxa are needed to evaluate these findings further. Within the Gerrhonotinae, available data support a sister relationship between Elgaria and the other genera.

Fossils from the late Cretaceous (ca. 75–95 million years ago) of Europe have been assigned to a distinct subfamily (Glyptosaurinae) within the Anguidae. European fossils that may represent anguines or their close relatives are known from the Middle Eocene and later, and, according to J. A. Gauthier, fossils assigned to the Anguis-Ophisaurus apodus clade date back to the late Oligocene or early Miocene. On the other hand, Ophisaurus fossils are not known from North America before the late Miocene. The fossil record indicates that each anguid subfamily originated at least by the early Eocene (50–55 million years ago).

Physical characteristics

Anguids may be relatively small (e.g., Celestus macrotus and Elgaria parva) or extremely long (Anguis fragilis). Small bony elements called osteoderms are present beneath dorsal and ventral scales. A ventrolateral fold lined with tiny scales allows expansion of the armored skin when food, eggs, or developing young distend the body cavity. This fold is absent in the Anniellinae and most diploglossines. Limb reduction is common in this family, and some species lack limbs altogether. External ear openings are present in most species, but several species lack them. In diploglossines and gerrhonotines, the tail is usually shorter than the body, but in anguines the tail is much longer than the body. Anniellines have a very short tail, typically less than two-thirds of the body length.

Caudal autotomy (self-amputation) is widespread among anguids, and fracture planes are present in some caudal vertebrae. Species of Abronia are specialized for an arboreal existence and have prehensile tails. Many anguids are some shade of bronze or brown (e.g., Ophisaurus attenuatus and Elgaria kingii), but some species exhibit more strking coloration (e.g., various shades of green in some Abronia and bright bands in some Diploglossus). Some species, such as Diploglossus fasciatus, may be boldly patterned. L. Vitt has suggested that D. lessonae juveniles mimic a toxic species of millipede with their bold markings.

Distribution

The Anniellinae, Diploglossinae, and Gerrhonotinae are restricted to the New World, but the Anguinae has representatives in North America, Europe, Asia, and North Africa. Phylogenetic analyses conducted by J. R. Macey and his colleagues suggest that anguids originated in the Northern Hemisphere (probably in North America) and only later colonized Africa and South America. Anguids are absent from sub-Saharan Africa, Madagascar, and Australia. Anguids occur from sea level to at least 12,470 ft (3,800 m).

Habitat

Anguids occur in a variety of habitats, from coastal dunes and desert scrub to grasslands above the tree line on tropical mountains. They inhabit a variety of forest types, from pineoak forest to lowland wet forest to cloud forest. While many anguid species are terrestrial, others are fossorial or arboreal.

Behavior

Most anguids easily autotomize (self-amputate) their tails when grasped, and the fragility of this appendage makes the name glass lizards (for Ophisaurus) particularly appropriate. Some anguids are active by day (e.g., Anguis fragilis), but others are nocturnal (e.g., some Diploglossus). Their slow movements and tendency to utilize leaf litter and other surface cover often render these lizards fairly inconspicuous.

Feeding ecology and diet

Anguids are carnivores that rely heavily on arthropod prey. These lizards typically move slowly and deliberately when foraging. In addition to arthropods, they take snails, slugs, nestling rodents, and other small vertebrates.

Reproductive biology

Both live birth and egg laying are widespread in this family. Anniellines give live birth to one to two young. Within the Anguinae, Anguis gives live birth, but all species of Ophisaurus lay eggs that are attended by the female. Both egg laying and live birth are found in the Diploglossinae and Gerrhonotinae.

Conservation status

The current IUCN listings underestimate the number of imperiled anguid species. The genus Abronia is in serious jeopardy from habitat destruction, as discussed thoughtfully by J. Campbell and D. Frost. Habitat destruction is also a grave problem for anguids in the West Indies.

Significance to humans

Anguids are in no way dangerous to humans and do not have commercial value outside the pet trade. As with all lizard groups, some anguids are erroneously believed to be venomous. Some people mistakenly think that the regenerated tail tip in Ophisaurus is a stinger.

Species accounts

Resources

Bons, Jacques, and Philippe Geniez. Amphibiens et Reptiles du Maroc. Barcelona: Asociación Herpetológica Española, 1996.

Grismer, L. Lee. Amphibians and Reptiles of Baja California, Including Its Pacific Islands and the Islands in the Sea of Cortés. Berkeley: University of California Press, 2002.

Savage, Jay M. The Amphibians and Reptiles of Costa Rica. Chicago: University of Chicago Press, 2002.

Schleich, H. Hermann, Werner Kästle, and Klaus Kabisch. Amphibians and Reptiles of North Africa. Koenigstein, Germany: Koeltz Scientific Publishers, 1996.

Campbell, Jonathan A., and José L. Camarillo. "A New Lizard of the Genus Diploglossus (Anguidae: Diploglossinae) from Mexico, with a Review of the Mexican and Northern Central American Species." Herpetologica 50 (1994): 193–209.

Campbell, Jonathan A., and Darrel R. Frost. "Anguid Lizards of the Genus Abronia: Revisionary Notes, Descriptions of Four New Species, a Phylogenetic Analysis, and Key." Bulletin of the American Museum of Natural History 216 (1993): 1–121.

Gauthier, Jacques A. "Fossil Xenosaurid and Anguid Lizards from the Early Eocene Wasatch Formation, Southeast Wyoming, and a Revision of the Anguioidea." Contributions to Geology (University of Wyoming) 21 (1982): 7–54.

Good, David A. "Phylogenetic Relationships Among Gerrhonotine Lizards." University of California Publications in Zoology 121 (1988): 1–138.

Macey, J. Robert, James A. Schulte II, Allan Larson, Boris S. Tuniyev, Nikolai Orlov, and Theodore J. Papenfuss. "Molecular Phylogenetics, tRNA Evolution, and Historical Biogeography in Anguid Lizards and Related Taxonomic Families." Molecular Phylogenetics and Evolution 12 (1999): 250–272.

Savage, Jay M., and Karen R. Lips. "A Review of the Status and Biogeography of the Lizard Genera Celestus and Diploglossus (Squamata: Anguidae), with Description of Two New Species from Costa Rica." Revista de Biologia Tropical 41, no. 3 (1993): 817–842.

Vitt, Laurie J. "Mimicry of Millipedes and Centipedes by Elongate Terrestrial Vertebrates." Research and Exploration 8 (1992): 76–95.

[Article by: Ronald L. Gutberlet, Jr., PhD]

The noun has one meaning:

Meaning #1: alligator lizards
  Synonym: family Anguidae

Anguidae
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Reptilia Order: Squamata Family: Anguidae
Genera
Anguis Ophisaurus Pseudopus Celestus Diploglossus Ophiodes Abronia Barisia Coloptychon Elgaria Gerrhonotus Mesaspis

Classification

Family Anguidae

• Subfamily Anguinae
  • Genus Anguis
  • Genus Ophisaurus
  • Genus Pseudopus
• Subfamily Diploglossinae
  • Genus Celestus
  • Genus Diploglossus
  • Genus Ophiodes
• Subfamily Gerrhonotinae
  • Genus Abronia
  • Genus Barisia
  • Genus Coloptychon
  • Genus Elgaria
  • Genus Gerrhonotus
  • Genus Mesaspis

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)