Both reading passage and the lecturer discuss about whether a 70 million year old fossil of T, rex contained actual tissues. The article maintains the materials found in T.rex are exactly remains of blood vessels, red blood cells and collagen matrix. However, the professor casts doubt on all of the points for the following reasons.
Firstly, the author in the passage believe that there is flexible organic substance inside the channels of the fossilized leg bone. Nonetheless, the lecturer refutes that the substance might be something else. After dinosaurs die, some bacteria will colonize their bodies. Thus those remains could be the residues of bacteria colonies instead of blood vessels.
In addition, the reading passage contends that there are some spheres found in microscopic examination, and those spheres might be red blood cells as tests indicates the spheres contained iron. However, the professor disagrees with the idea, and he argues that in fact researchers also found identical spheres on other animals and organisms that lived without blood cells. As a result, the spheres are probably just other minerals.
Last but not least, the article believes that the dinosaur leg bone had collagen, which is a major component of living bone tissue. Once again, the professor mentions that collagen now we found could not be older than 100 thousand years, because collagen can not last that longer. Thus those bone tissues might not come from T. rex but from some human collagens.
To conclude, the professor effectively refutes all of the points presented in the articles.