Scientists don't know much about ancient animals like dinosaurs. Every year marine fossils are discovered and they change the theory that was stated before. For example scientists now believe the T-Rex chirped like a bird, didn't run as fast and had feathers like a chicken. In a fossil in Australia, scientists now know the exact shape of the heart of an arthrodire fish that lived around 380 million years ago.
What makes this discovery even more interesting is that the shape of the heart is preserved in its original shape and is not flattened even though it is hundreds of millions of years old. The scientists then used neutron beams and synchotron x-rays to scan the heart's structure preserved in the limestone layers.
The result is that scientists have now discovered that the heart of this fish is S-shaped with two chambers. Based on these specimens, scientists get more information about how the heart organ has evolved over hundreds of years. In addition to the heart, the organs of the liver, intestines and stomach of this fish are also well preserved. This is not the first time fossils have been found in fossils that are millions of years old. Last year a dinosaur embryo in an egg was found in China.