Rare reptile holds clue to penis evolution
Like other reptiles and mammals, tuatara embryos start budding male genitalia — but then lose it
![tuatara](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2015/10/102715_sm_tuatara_free.jpg?fit=860%2C460&ssl=1)
LOST IT Deep in the evolution of New Zealand’s lizardlike tuatara, adult males probably lost their ancestral phallus — a clue to the ancient history of the penis.
Sid Mosdell/Flickr (CC BY 2.0)