Editing Skin (section)

===Birds and reptiles===
{{Main|Reptile scales}}
{{One source section|date=August 2021}}

The [[epidermis (skin)|epidermis]] of [[bird]]s and [[reptile]]s is closer to that of [[mammals]], with a layer of dead keratin-filled [[cell (biology)|cells]] at the surface, to help reduce water loss. A similar pattern is also seen in some of the more terrestrial [[amphibians]] such as [[toad]]s. In these animals, there is no clear [[cell differentiation|differentiation]] of the [[epidermis (skin)|epidermis]] into distinct layers, as occurs in [[human]]s, with the change in [[cell (biology)|cell]] type being relatively gradual. The mammalian [[epidermis (skin)|epidermis]] always possesses at least a [[stratum germinativum]] and [[stratum corneum]], but the other intermediate layers found in [[human]]s are not always distinguishable.
[[Hair]] is a distinctive feature of mammalian skin, while [[feather]]s are (at least among living species) similarly unique to [[bird]]s.<ref name=VB>{{cite book |author=Romer, Alfred Sherwood|author2=Parsons, Thomas S.|year=1977 |title=The Vertebrate Body |publisher=Holt-Saunders International |location= Philadelphia|pages= 129–145|isbn= 978-0-03-910284-5}}</ref>

[[Bird]]s and [[reptile]]s have relatively few skin [[gland]]s, although there may be a few structures for specific purposes, such as [[pheromone]]-secreting [[cell (biology)|cells]] in some [[reptile]]s, or the [[uropygial gland]] of most birds.<ref name=VB/>