A specimen nicknamed "Willo" may be the first dinosaur ever found with a fossilized heart. Some scientists further suggest that the organ is a four-chambered heart more like those of mammals or ...

To put it in non-medical terms, I was born with the heart of an amphibian. A normal human heart has four chambers; I only have three as the lower two are joined as one chamber.

Did you know that heart structures vary across species? Mammals, like ferrets and humans, have four-chambered hearts. Birds also have four-chambered hearts, similar to mammals. Reptiles and ...