Scincomorpha is an

infraorder Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and ...

and clade of lizards including

skinks Skinks are lizards belonging to the family Scincidae, a family in the infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one of the most diverse families of lizards. Sk ...

(Scincidae) and their close relatives. These include the living families

Cordylidae Cordylidae is a family of small- to medium-sized lizards that occur in southern and eastern Africa. They are commonly known as girdled lizards, spinytail lizards, or girdle-tail lizards. Cordylidae is closely related to the family Gerrhosauridae ...

(girdled lizards),

Gerrhosauridae The Gerrhosauridae are a family of lizards native to Africa and Madagascar. Habitat Also known as plated lizards, species in the family Gerrhosauridae live in a range of habitats, from rocky crevices to sand dunes. Description Their form is va ...

(plated lizards), and Xantusiidae (night lizards), as well as many extinct taxa. Other roughly equivalent terms include the suborder Scinciformata, or the superfamily Scincoidea, though different authors use these terms in a broader or more restricted usage relative to true skinks. They first appear in the fossil record about 170 million years ago, during the

Jurassic The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...

period.Evans, S.E. and Jones, M.E.H. (2010). "The Origin, Early History and Diversification of Lepidosauromorph Reptiles," pp. 27-44 in Bandyopadhyay, S. (ed.), ''New Aspects of Mesozoic Biodiversity'', 27 Lecture Notes in Earth Sciences 132.

/ref> The phylogeny below follows that of Alifanov in 2016. Image:Polyglyphanadon sternbergi - IMG 0694.jpg, '' Polyglyphanodon, Polyglyphanodon sternbergi'' File:Bronze Grass Skink (Mabuya macularia) W IMG_2753.jpg, '' Eutropis macularia'' There are many characteristics that are shared upon all skinks. All skinks have very cone shaped heads with large, symmetrical, and shield-like scales. Their scales are smooth, glossy, and circular all throughout their body. Once you get to their back and belly areas, they have more round scales that overlap like roof shingles. Their bodies are cylindrical in their cross section and have body scales that have bony plates underneath them called “osteoderms”. Osteoderms are dermal bone structures that support the upper layer of skin and serve as protection against the elements in a large variety of extinct and extant organisms, especially reptiles. This structure is commonly called "dermal armor" and serves to protect the organism, while also helping with temperature regulation. The roofs of their mouths are made up of two bony plates instead of one. One of their bony plates is called a palate and the other bony palate in the roof of their mouth separates the respiratory and digestive passages. They also have very long tapering tails with small legs and five toes. For their distribution, there are around 1,275 species of skinks all around the world. They are very popular and can be mostly found in Southeast Asia, the deserts of Australia, and temperate regions of North America. There are also desert species skinks that are called “sand swimmers” that are found in Florida. Five-lined skinks are very popular throughout Georgia and North Carolina, they are found in very wooded areas and like to hide in fallen trees. Skinks are more abundant and endangered in Africa and Indo Australia because of predators and loss of habitat. Another very popular area is New Zealand, the pale-flecked garden sunskink (Lampropholis guichenoti) is very common. They are also found in the suburban gardens in Auckland. Some skink species are more terrestrial and fossorial, some arboreal meaning tree-dwelling, and others are semiaquatic.

References

(Skinks (Scincidae) ." Grzimek's Animal Life Encyclopedia. . Retrieved March 25, 2021 from Encyclopedia.com: https://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/skinks-scincidae) (Vitt, L. (2018, October 10). Skink. Encyclopædia Britannica. https://www.britannica.com/animal/skink) Bajocian first appearances Extant Middle Jurassic first appearances Vertebrate infraorders {{lizard-stub