Introduction: Secrets of Bones: Sex (2:24) --
Gorilla's Sagittal Crest (3:04) --
Canines for Courtship (1:51) --
Babirusa's Curly Tusks (2:50) --
Narwhal's Sensitive Tusk (2:57) --
Fighting Rival Suitors (2:33) --
Head-butting Bighorns (1:44) --
Skull Crushing Experiment (3:12) --
Credits: Secrets of Bones: Sex (0:41).
