foot]]
A scute or scutum (Latin scutum, plural: scuta "shield") is a bony external plate or scale, as on the shell of a turtle, the skin of crocodilians, the feet of some birds or the anterior portion of the mesonotum in insects.
Properties
Scutes are similar to
scales and serve the same function. Unlike the scales of fish and snakes, which are formed from the
epidermis, scutes are formed in the lower vascular layer of the skin and the epidermal element is only the top surface. Forming in the living
dermis, the scutes produce a
horny outer layer, that is superficially similar to that of scales. Scutes will usually not overlap as
snake scales (but see the
pangolin). The outer
keratin layer is shed piecemeal, and not in one continuous layer of skin as seen in snakes or lizards. The dermal base may contain
bone and produce
dermal armour. Scutes with a bony base are properly called
osteoderms. Dermal scutes are also found in the feet of
birds and tails of some
mammals, and are believed to be the primitive form of dermal armour in reptiles.
The term is also used to describe the heavy armour of the armadillo and the extinct glyptodon, and is occasionally used as an alternative to scales in describing snakes or certain fishes, such as sturgeons.
Turtle scutes
The turtle's
carapace is a massive scute structure, formed by a series of distinct scutes with a bony base that have grown together to form the shell. The individual scutes are termed nuchal scute, central or vertebral or neural scutes, costal scutes, marginal scutes, and pygal or supracaudal scute. Those in the
plastron are the epiplastron, entoplastron, hyoplastron, and hypoplastron. The horny surface of the scutes are shed individually, usually over a few days.
Insect scutes
The term "scutum" is also used in
insect anatomy, as an alternative name for the anterior portion of the
mesonotum (and, technically, the
metanotum, though rarely applied in that context).
See also
Osteoderms
Scale (zoology)
Snake scales
Keratin
Skin
Skeleton
Category:Animal anatomy
Category:Dinosaur anatomy
![The Northern Map Turtle (Graptemys geographica), or formerly Common Map Turtle[1], is an aquatic turtle belong to the family of Emydidae.](http://web.archive.org./web/20110903145341im_/http://cdn3.wn.com/pd/30/98/15f7421a12ac089122dafe99b3de_grande.jpg "The Northern Map Turtle (Graptemys geographica), or formerly Common Map Turtle[1], is an aquatic turtle belong to the family of Emydidae.")
![Painted Turtle (Chrysemys picta) is a reptile that is common in southern Canada, the United States, and northern Mexico and is related to other water turtles such as sliders and cooters. This turtle lives in ponds, lakes, marshes, and in slow-moving rivers that have soft, muddy bottoms. The maximum carapace size, or shell length, for painted turtles is or 25 cm (10 in.).[1] Its shell is used to protect it from its predators.](http://web.archive.org./web/20110903145341im_/http://cdn1.wn.com/pd/4d/58/8b1731b4d6058642de34cf7a83ba_grande.jpg "Painted Turtle (Chrysemys picta) is a reptile that is common in southern Canada, the United States, and northern Mexico and is related to other water turtles such as sliders and cooters. This turtle lives in ponds, lakes, marshes, and in slow-moving rivers that have soft, muddy bottoms. The maximum carapace size, or shell length, for painted turtles is or 25 cm (10 in.).[1] Its shell is used to protect it from its predators.")
![The Northern Map Turtle (Graptemys geographica), or formerly Common Map Turtle[1], is an aquatic turtle belong to the family of Emydidae.](http://web.archive.org./web/20110903145341im_/http://cdn2.wn.com/pd/30/98/15f7421a12ac089122dafe99b3de_thumb.jpg "The Northern Map Turtle (Graptemys geographica), or formerly Common Map Turtle[1], is an aquatic turtle belong to the family of Emydidae.")
![Painted Turtle (Chrysemys picta) is a reptile that is common in southern Canada, the United States, and northern Mexico and is related to other water turtles such as sliders and cooters. This turtle lives in ponds, lakes, marshes, and in slow-moving rivers that have soft, muddy bottoms. The maximum carapace size, or shell length, for painted turtles is or 25 cm (10 in.).[1] Its shell is used to protect it from its predators.](http://web.archive.org./web/20110903145341im_/http://cdn0.wn.com/pd/4d/58/8b1731b4d6058642de34cf7a83ba_thumb.jpg "Painted Turtle (Chrysemys picta) is a reptile that is common in southern Canada, the United States, and northern Mexico and is related to other water turtles such as sliders and cooters. This turtle lives in ponds, lakes, marshes, and in slow-moving rivers that have soft, muddy bottoms. The maximum carapace size, or shell length, for painted turtles is or 25 cm (10 in.).[1] Its shell is used to protect it from its predators.")
