Super Lungs

Remaining on the subject of dinosaurs and birds we have a really interesting post at https://phys.org/print459590617.html … biologists have speculated that birds descend from one branch of the dinosaurs. Not all dinosaurs are related to birds – but some are. This is the theory. It seems birds have a unique respiratory system which enables powered flight. The question is being asked – did dinosaurs have a similar respiratory system (allowing them to run like Velociraptor). Unlike mammals, including humans, whose lungs expand and contract with effort, bird lungs are rigid. Air sacs alongside the lungs pump air throught the lungs instead. Now, a study in Royal Society Open Science has found birds and dinosaurs shared the same kind of lung. They sport a costovertebral joint where the rib meets the vertebrae and this allows for a continuous stream of oxygen. It requires less energhy than inflating and deflating the lungs. However, not all paleontologists are onboard as the theory is based on bones – as lungs are soft tissue and do not fossilise (or have not been found in a fossilised state, as yet). It would explain the ability of velociraptors to run at extremely fast speeds.