How did digits evolve? While it is clear that they derive from genetic programs already present in fish, their precise origin remains a matter of debate. An international team led by the University of ...

Despite the huge number of dinosaur fossils found, from bones to feathers, precious little exists in the fossil record to explain dinosaur defecation, urination, or copulation. Thankfully, all three ...

Jan. 19 (UPI) --For the first time, scientists have described the cloaca, or vent, of a dinosaur -- the all-purpose opening used for reproduction and waste disposal. Many mammals have distinct ...

(This article forms a part of the Science for All newsletter that takes the jargon out of science and puts the fun in! Subscribe now!) The transition from fins to limbs is one of the most important ...

Zoologically speaking, the cloaca is the undifferentiated posterior orifice in birds, reptiles, and amphibians. It serves urinary, digestive, and reproductive functions carried out by specialized ...

As a result, the cloaca is divided into the urogenital sinus and rectum, and the tip of the URS (endodermal epithelia) contributes to forming the ectodermal epithelia of the perineum and external ...