Female birds have no uterus or vagina, the oviduct empties into the cloaca." Related: Strange love: 13 animals with truly weird courtship rituals Kevin J. McGowan, PhD ...

But how did we get from dinosaur’s prehistoric holes to the modern bird cloaca? The Psittacosaurus specimen from Liaoning is our best glimpse to date. A close-up of the cloaca, within an off ...

Birds have one hole to get rid of waste, called a cloaca. The cloaca is the multitool of a bird's anatomy: It leads to the urinary, digestive and reproductive tracts.

Mating behavior in many birds is forced. But when birds such as chickens mate via what's described as a "cloacal kiss," sperm can't enter a female unless she cooperates and turns her cloaca inside ...

The cloaca is the part of the bird’s body which stores urates, feces, urine and egg. The cloacal lips (or vent) are used to control the passage and frequency of droppings and other eliminations.

Most bird species don’t have “traditional” penises and vaginas (though there are some bizarre exceptions). Instead, both sexes have a cloaca — an all-purpose entrance and exit for the ...

The evolutionary reason why these birds don’t have penises remains a mystery. But new research has finally shed light on the genetic factors that prevent male land birds from growing penises as ...

The cloaca of birds, our present-day dinosaurs, look “kind of like a cyst that needs to be popped,” Vintehr explains, while the cloaca of crocodile are covered in distinct scales, ...

Birds and reptiles have a cloaca – a single orifice used for excretion, urination, mating and laying eggs – so it has always been assumed that dinosaurs had them too.The cloaca of the ...

For the first time, scientists have described the cloaca, or vent, of a dinosaur ... Though birds are prolific sexual signalers, their cloacas aren't all that conspicuous.

This cloaca is more than 100 million years old, and it did a lot of work for this extinct species. By Katherine J. Wu The world’s oldest known all-purpose orifice sits in a fossil display case ...