For animals like dinosaurs that lived hundreds of millions of years ago, a challenging question is: how long can they live? If you consult different popular science articles, you will get different answers. For giant sauropods, some people think they lived only a few decades, but others think they can live to hundreds of years. The main reason for such a big gap is that the longevity of dinosaurs is not only related to their size, but also related to their metabolic rate.
For example, if dinosaurs were thermostatic animals like birds, their life would be shorter; On the contrary, if dinosaurs were more like variable temperature animals such as crocodiles, they could live longer. The method of estimating the life span of dinosaurs by body size and metabolic rate is very rough and inaccurate, because the comparative data of this method are living animals that are significantly different from dinosaurs. So, is there a more accurate way to predict the life span of dinosaurs?
By studying the microstructure of dinosaur bones, scientists have found a relatively reliable method to calculate the life span of dinosaurs. Scientists found that the cross section of dinosaur bones had structures like tree rings. By calculating the number of such structures, we can infer the death age of dinosaurs. At the same time, by observing the microstructure characteristics of dinosaur bones, we can also judge whether the research object died in childhood, youth or old age. Combined with this information, we can roughly judge the life span of a certain dinosaur.
Generally speaking, sauropod dinosaurs can live to 40-60 years old, maybe longer; Large theropod dinosaurs, like the famous Tyrannosaurus Rex, can live for about 25 years; Small theropod dinosaurs, like little Raptor, can only live for 3 ~ 4 years; It is also a small dinosaur. Parrot billed dinosaurs belonging to horned dinosaurs can live longer than 10 years, which may reflect that horned dinosaurs and small theropods have different metabolic levels.