What is bone, hair, feather, fish and reptile scale made of? Epidermal or dermal tissue?

1 Answer
Jan 2, 2017

Please remember that in case of vertebrates, epidermis is ectodermal in origin while dermis is mesodermal . Both these are related to skin : epidermis is keratinised outer protective layer while dermis is underlying connective tissue.

Explanation:

Keratinised epidermal derivatives in vertebrates are many, e.g.:

REPTILIAN SCALES
AVIAN FEATHERS
MAMMALIAN HAIRS
CLAWS
HOOVES
HORNS
etc.

Scales of fish are different from reptilian scale for being dermal in origin.

Please note that BONE, muscles, and all connective tissues are mesodermal in origin.