TPO24

The passage talks about some theories which made when researchers deliberately broke the leg bone of the 70 million yers old fossil of Tyrannosaurus. However, the professor makes some skepticism about these theories. And he refutes all of them.

To begin with, the passage states that researchers find many small branching channels attributed to blood vessels and a soft organic substance which means the presence of actual blood. The professor rejects this idea. He says that this substance can be the chemical remains of the bacteria which live inside the bones.

Second, the passage declares the presence of spheres that could be the sign of red blood cells. The professor opposes this reason. He adds that these spheres were found in fossils of other animals buried in that area. These animals do not have any blood cells. As a result, the spheres might be the sign of reddish mineral.

Finally, the passage mentions collagen as an evidence for researchers theory. The professor refutes this point by comparing the 100-year lasting time for collagen in comparison the old of the fossil. He says that the collagen that the scientists found could be from their own skin because the remains of collagen can not be found in that old fossils.