Anguidae refers to a large and diverse family of lizards native to the Northern Hemisphere. Common characteristics of this group include a reduced supratemporal arch, striations on the medial faces of tooth crowns, osteoderms, and a lateral fold in the skin of most taxa.[1] The group includes the slowworms, glass lizards, and alligator lizards, among others. The family is divided into three subfamilies (Anguinae, Diploglossinae, and Gerrhonotinae), and contains about 100 species in 10 genera.

Anguidae
Temporal range: Campanian–Recent
Anguidae.jpg
Anguis fragilis (slow worm)
Gerrhonotus parvus 5880611.jpg
Gerrhonotus parvus
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Clade: Anguioidea
Family: Anguidae
Gray, 1825
Subfamilies

Morphology and reproductionEdit

Anguids have hard osteoderms beneath their scales giving them an armored appearance. Many of the species have reduced or absent limbs, giving them a snake-like appearance, while others are fully limbed.[2] Body type varies among species, with sizes ranging from 10 cm to 1.5 m. The group includes oviparous and viviparous species, both of which can be observed in a single genus at times.[2][1]

Feeding and habitatEdit

These lizards are known carnivorous or insectivorous foragers, feeding primarily on insects, although larger species have been known to feed on small reptiles and amphibians. They inhabit a wide range of different habitats across the globe, from arid to tropical environments. Most known species are terrestrial or semifossorial, with the exception of one arboreal genus: Abronia.[1]

EvolutionEdit

 
Helodermoides tuberculatus fossil

Anguids have a relatively good fossil record and are relatively common as fossils in the Late Cretaceous and Paleogene of western North America. The oldest known anguid, with the most complete fossil record of any lizard, is Odaxosaurus, a member of the extinct anguid subfamily Glyptosaurinae, from the late Campanian of Canada, about 75 million years ago. Odaxosaurus and other Late Cretaceous anguids already exhibit many features found in living anguids, including chisel-like teeth and armor plates in the skin, suggesting a long evolutionary history for the group. Anguids were particularly diverse during the Paleocene and Eocene in North America; some species, such as those belonging to Glyptosaurinae, [1] grew to large size and evolved a highly specialized crushing dentition. The long fossil record for the Anguidae in North America suggests that the group probably evolved in North America during the Cretaceous before dispersing to Europe in the Paleogene.

 
This figure shows a simplified phylogeny of the Anguid subfamilies based on maximum-likelihood analysis of mitochondrial DNA sequence data.[3]

ClassificationEdit

Family ANGUIDAE

  • Subfamily Anguinae
    • Genus Anguis - slowworms (two species)
    • Genus Dopasia - Asian glass lizards (seven species)
    • Genus Hyalosaurus - North African glass lizard (one species)
    • Genus Ophisaurus - American glass lizards (five species)
    • Genus Pseudopus - scheltopusik (one extant species)
  • Subfamily Diploglossinae
  • Subfamily Gerrhonotinae - alligator lizards
    • Genus Gerrhonotus - alligator lizards (seven species)
    • Genus Abronia - arboreal alligator lizards (29 species)
    • Genus Elgaria - western alligator lizards (seven species)
  • SubfamilyGlyptosaurinae

Genetic evidence indicates that Diploglossinae lies outside the clade containing Anguinae, Gerrhonotinae, and the family Anniellidae, Therefore it has been placed in own separate family Diploglossidae.[4]

ReferencesEdit

  1. ^ a b c d "Anguidae". Animal Diversity Web. Retrieved 2017-05-02.
  2. ^ a b Bauer, Aaron M. (1998). Cogger, H.G.; Zweifel, R.G. (eds.). Encyclopedia of Reptiles and Amphibians. San Diego: Academic Press. pp. 152–155. ISBN 0-12-178560-2.
  3. ^ Wiens, J. J.; Slingluff, J. L. (2001-11-11). "How lizards turn into snakes: a phylogenetic analysis of body-form evolution in anguid lizards". Evolution; International Journal of Organic Evolution. 55 (11): 2303–2318. doi:10.1111/j.0014-3820.2001.tb00744.x. ISSN 0014-3820. PMID 11794789. S2CID 2235211.
  4. ^ Burbrink, Frank T; Grazziotin, Felipe G; Pyron, R Alexander; Cundall, David; Donnellan, Steve; Irish, Frances; Keogh, J Scott; Kraus, Fred; Murphy, Robert W; Noonan, Brice; Raxworthy, Christopher J (2020-05-01). Thomson, Robert (ed.). "Interrogating Genomic-Scale Data for Squamata (Lizards, Snakes, and Amphisbaenians) Shows no Support for Key Traditional Morphological Relationships". Systematic Biology. 69 (3): 502–520. doi:10.1093/sysbio/syz062. ISSN 1063-5157. PMID 31550008.

External linksEdit