scute

osteoderm

A bony external plate or scale, as on the shell of a turtle, the skin of crocodilians, the feet of some birds. 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[WP].

النوع Bone
الاسم اللاتيني osteoderm

الأسئلة الشائعة

What is a scute?
A scute (or scutum) is a bony external plate or scale found in certain animals, formed in the lower, vascular layer of the skin (dermis). Unlike fish scales, scutes are true dermal bones that are part of the animal's skeletal armor.
In which animals are scutes found?
Scutes are found in turtles and tortoises (forming the carapace and plastron), crocodilians (forming the dorsal armor), and some birds (on the legs and feet). Certain fish and extinct groups like ankylosaurs also had scute-like structures.
How do scutes differ from fish scales?
Scutes are formed in the lower, vascular (dermal) layer of the skin and are true bone-like structures, whereas fish scales develop in the outer scales layer and have a different composition and embryological origin.
What is the composition of scutes?
Scutes are composed of bone-like material (dermal bone) covered by a keratinous layer. In turtles, the outer keratinous layer forms the visible scutes (shields), while the underlying bony plates fused to the vertebrae form the true shell.
What is the function of scutes?
Scutes serve primarily as protective armor against predators and physical trauma. In turtles, they form the shell providing rigid protection for internal organs. In crocodilians, dorsal scutes provide protection and may assist in thermoregulation.

البنى ذات الصلة

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This content is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for medical decisions.

Data sources: Terminologia Anatomica, Foundational Model of Anatomy, Wikidata.