Bearded dragon integumentary system — spiny scales, the beard, and patch shedding
Overview of bearded dragon skin — keratinized scales with enlarged spiny rows along the flanks and throat, a beard flared by the hyoid skeleton and darkened by pigment cells, and shedding in patches rather than one piece.
General educational reference only — not clinical or veterinary advice. Anatomy varies between individual animals; consult a licensed veterinarian for any health concern.
Scales and spines
The body is covered in small keratinized scales, broken along the flanks, the back of the head and the throat by rows of enlarged, cone-shaped spiny scales. For all their armored look, these spines are made of the same keratin as the rest of the skin and are flexible rather than sharp. The scaled epidermis is highly resistant to water loss — the skin of a desert lizard — and, as in most reptiles, carries almost no glands.
The beard
The beard itself is a pouch of spiny throat skin underlain by the hyoid apparatus, the bony and cartilaginous skeleton of the tongue and throat. Swinging the long horns of the hyoid outward and downward stretches the pouch into a broad, erected frill. At the same time pigment cells in the skin can darken it to near-black within minutes; both sexes carry a beard and can flare and darken it, and darkening of the skin more generally also increases heat uptake while basking.
Shedding and skin pores
Bearded dragons renew the epidermis the way most lizards do: a new layer forms beneath the old, and the outer skin loosens and comes away in patches over days rather than in one piece as in snakes. Fast-growing juveniles shed far more often than adults. On the underside, a row of femoral pores along each thigh and preanal pores in front of the vent — larger and more waxy in males — secrete material used in scent marking.
