Study reveals male alligators have permanently erect penises which they keep hidden inside their bodies

The reproductive organ of a male alligator is constantly erect and hidden inside its body, a study has found.
Scientists have discovered a significant anatomical difference between the phallus of the reptile and that of a majority of other animals.
The penis of the American alligator is made of tough, fibrous tissue which sees it constantly fully erect inside its reproductive tract and ejected from the body during mating.
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Alligator anatomy: Scientists have found that the penis of the male alligator does not inflate before mating but is constantly fully erect and hidden inside its body

This means that the male alligator’s reproductive organs do not change shape or size when aroused, and does not require inflation for mating.
When alligators copulate the male ejects his penis from his body and retracts it at equal speed, according to the study published in journal Anatomical Record.

'It is really interesting and really bizarre, very different from anything we've seen in vertebrates,’ Diane Kelly, an anatomist at the University of Massachusetts and author of the study, told Live Science.
Ms Kelly said early 20th century scientists had described the alligator’s penis but had concluded ‘I have no idea how this thing works’.

Before: The reproductive tract of an alligator showing the muscles controlling the ejection in a relaxed state

After: The scientists tug at the muscle tendons to showcase the dissected alligator's penis which is in the same state inside and outside of the body

Ms Kelly studied several American alligators and upon dissection found a 2.75in white phallus hidden inside the reptiles reproductive and waste orifice.
Ms Kelly filled the phallus with saline fluid and discovered that, unlike a majority of mammals, turtles and birds, the penis did not change in shape and size.
Upon dissection she found the penis full of collagen leaving it too stiff to inflate pre-reproduction.
‘The large amount of collagen in the wall and central space of the alligator penis stiffen the structure so it can be simply everted for copulation and rapidly retracted at its completion,’ Dr Kelly explains.
The phallus is ejected with a specific set of muscles and retracted when the animal relaxes the muscles with the help of ‘rubber band’ tendons at its base.

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