Can't believe the downvoting. There's several major issues with the current dinosaur theory RN.
Four areas of scientific incongruities regarding these animals’ large size are 1) insufficient muscle strength, 2) insufficient bone strength, 3) unacceptably high blood pressure within the tallest dinosaurs, and 4) the paradox of pterosaurs having grossly insufficient power to fly in atmospheric conditions similar to the present
Today there are no reptiles capable of generating the power needed to fly, and yet during the Mesozoic era reptiles grew to be the largest flying animals that ever existed. The largest of these pterosaurs was the Quetzalcoatlus. It had a chest size as large as a horse and stood as tall as a giraffe ... [Y]et some paleontologists continue to insist that there is no scientific paradox regarding how the pterosaurs could have flown ... [P]terosaurs could not have flown in today’s atmospheric environment. The application of aerodynamic equations show pterosaurs falling far short of meeting the requirements for obtaining flight in today’s atmosphere, and the experimental efforts using RC models provide physical evidence confirming these conclusions. It should be alarming to all scientists and science educators that some paleontologists continue to claim that they understand how pterosaurs flew when the evidence is so overwhelming in refuting their claim ...