Mammal penis

In male human anatomy, the foreskin, also known as the prepuce (), is the double-layered fold of skin, mucosal and muscular tissue at the distal end of the human penis that covers the glans and the urinary meatus. The foreskin is attached to the glans by an elastic band of tissue, known as the frenulum. The outer skin of the foreskin meets with the inner preputial mucosa at the area of the mucocutaneous junction. The foreskin is mobile, fairly stretchable and sustains the glans in a moist environment. Except for humans, a similar structure known as a penile sheath appears in the male sexual or

thumb|320px|Baculum of a dog's penis; the arrow shows the urethral sulcus, which is the groove in which the urethra lies. thumb|Fossil baculum of a Indarctos|bear (Indarctos) from the [[Miocene]]

anatomical structure

pointed structures on the penile glans and/or shaft

Marine Mammal Anatomy