Researchers think they have answered the biological mystery of why reptiles have two penises and birds and mammals with the exception of that guy on Reddit only have one. The answer, according to a paper published in Nature yesterday is that it depends on the location of the embryonic cloaca, which eventually develops into the urinary tract. The cloaca issues signals telling neighbouring cells to form into genitals.
Snakes and lizards have two penises, not just one. They are called hemipenes. Their functions are poorly known, but should be considered a defining characteristic of female lizards and snakes.
Reptiles have unusual reproductive equipment. For example, female snakes and lizards have two clitorises. Meanwhile, the male tuatara has no penis.
Is it possible the unused hemipene helps exert a force on the female's tail that keeps the active one lodged in? I am thinking it could act as a fulcrum. This would be useful for both snakes and lizards.
As snakes emerge from hibernation, mating — not eating — is usually first on the menu, depending on the species. Snake sex can occur right after spring or continue throughout the summer into late fall, depending on the species. Some males fight for the right to have sex with the females, as with garter snakes for example.
All rights reserved. The male American alligator, Alligator mississippiensiskeeps its penis erect but tucked inside its body until mating. More than 10, reptile species in every shape and size scurry and slither across Earth, from garter snakes to crocodiles — and their nether regions are just as wildly varied.
This includes two separate hemipenes, which are the snake equivalent to a penis that pop out of the body during sex. Here, scientists determined that although the right-side reproductive system of gartersnakes is significantly larger than the left, each is used about half the time in the wild, often alternating from one to the other. However, when things get hot literally, as in hotter temperaturesthe males tend use their right hemipenes.