Three-dimensional reconstructions (3DR) (B-E) as well as sections (A, F-H) of the penis of an untreated adult male hyena. (A) Distal section, note urethral orifice (black arrowheads) opening onto the dorsal penile surface. Orange arrows pointing to 3DRs indicate positions of sections (A, F-H)). (B) 3DR, ¾ view of the distal end of the adult hyena penis. Skin is flesh color, urethral orifice (yellow) opens on the dorsal surface of the penis. (C) 3DR, side view with skin rendered semi-transparent to reveal the GEB (green) surrounding the urethra (yellow) and the corporal body (red). (D) 3DR of the mid-shaft of the penis. Note slit-like urethra (yellow arrow) surrounded by the purple corpus spongiosum. The tunica albuginea (white) surrounds both the corporal body (red), urethra and corpus spongiosum. Retractor muscles (blue) lie ventral to the penile urethra. (E) 3DR, side view with penile skin rendered invisible and the tunica (white) rendered semi-transparent to reveal internal structures. (F) Proximal section showing corporal body (CB), and corpus spongiosum (CS) surrounding the slit-like urethra (Ur). Retractor muscles (dotted lines) are ventral to the urethra. Orange arrow indicates the position in 3DR (E) from which section (F) was taken. (G) Section through to the glanular erectile body (GEB); the orange arrow indicates the position in 3DR (D) from which section (G) was taken. The tunica albuginea surrounds both the corporal body (CB) and urethra (Ur). (H) Section just proximal to the glanular erectile body (GEB); the orange arrow indicates the position in 3DR (E) from which section (H) was taken. The tunica surrounds the corporal body (CB), slit-like urethra (Ur) and corpus spongiosum (CS).