Close-up footage of an erect alligator penis is making waves in the natural history world after a post-mortem dissection shed new light on the mystery of how reptile's member works.
The weird and mildly repulsive clip shows Brandon Moore from Louisiana Tech University dissecting an American alligator, according to the National Geographic.
When he touches its pelvic nerve, out pops a white translucent penis from a scaled opening, followed by what is unmistakably the alligator's testicles, in footage National Geographic reporter Ed Yong nicknamed 'alligator penis surprise.'
The scaled opening from which the penis emerges is called a 'cloaca'. During mating, the aligator penis thrusts out of the cloaca and pumps sperm into the female's cloaca. However biologists have been mystified about how the penis jerks out and maintains its stiffness.
Diane Kelly from the University of Massachusetts told the National Geographic the footage was "really weird" and led her to a new hypothesis about how alligator penises work.
She already knew that the penis stayed fully erect all the time and was merely retracted in and out of the cloaca, but she didn't know how it popped out, especially as it was not attached to any muscles.
Now she believes that the organ comes out by a the contraction of pair of pelvic muscles that nestle the penis, but aren't actually attached to it, reducing the space in the cloacal chamber and squeezing the milky white member out.
It's not the first weird penis discovery made this week. Scientists have also discovered a sea slug with a detactable penis. The resourceful creature is also able to re-grow and re-use its penis, according to the study, published in the Royal Society's journal Biology Letters.