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Were dinosaurs cold-blooded or warm-blooded?
The diagram above shows energy usage in a number of animal groups, including birds, mammals, dinosaurs and modern reptiles. Dinosaurs were “mesotherms,” neither warm- nor cold-blooded, a new study finds.
Why do scientists think that dinosaurs look like lizards?
Head. Tyrannosaurs’ smooth, toothy skulls are quite reptilian. But unlike crocs or gators, dinosaurs were terrestrial, so they may have needed to trap moisture inside their mouths to stay hydrated. That’s why many depictions have partial lips, more akin to lizards.
How did researchers determine the body mass of dinosaurs?
First, they used growth rings and the dimensions of fossil dinosaur bones to estimate growth rate and body mass (respectively) of 21 species of extinct dinosaurs. Then, using the correlation between growth rate and metabolic rate across clades of living species, they predicted the dinosaurs’ metabolic rates.
How did researchers predict the metabolic rates of dinosaurs?
To determine the metabolic rate of different dinosaur species, the researchers used two of the available pieces of information in the fossil record: adult mass and maximum growth rate (bone growth rings). It should therefore also be a reliable approach to predict the metabolic rate of extinct species.
How do scientists know how dinosaurs sound?
Clues in dinosaur skulls have lead scientists to believe that these animals did make noises. Some, like “Lambeosaurus,” had crests on top of their heads that probably filled with air when the animal breathed. As air was pushed through these crests, they likely made a deep bellowing sound similar to a horn.
Were dinosaurs really reptiles?
Yes, dinosaurs are reptiles. Some have attempted to make it out that reptiles are a grade (as the original definition of the term included only lizards, snakes, the tuatara , turtles, and crocodilians ) rather than a clade, or that the term applies only to cold-blooded members of the group.
What animals are warm blooded?
A list of warm-blooded animals would include all mammals and birds (with very few exceptions), such as apes, monkeys, whales, elephants, cheetahs , giraffes, dogs, cats, pigs and humans. All reptiles, amphibians, fish and insects are considered cold-blooded.
Were dinosaurs reptiles or mammals?
Though there were some dinosaurs with mammal-like qualities, dinosaurs were actually reptiles; however, though the word “dinosaur” roughly translates to “terrible lizard” in Greek, dinosaurs were not actually lizards, either.
Were dinosaurs descended from birds?
Modern birds descended from a group of two-legged dinosaurs known as theropods , whose members include the towering Tyrannosaurus rex and the smaller velociraptors .