As we know, the life of dinosaurs began with a hard-shelled egg. They came in a variety of shapes and sizes depending on the species, but all had shells with internal structures more like the eggs of modern birds than the eggs of any living reptile.
But how long did dinosaurs' lives last? Life expectancy has been debated for many years as technology develops and scientists discover more information.
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How many years did dinosaurs live?
In general, scientists can measure the age of some species of dinosaur from the growth rings inside fossilized bones, just as they can tell the age of a tree from the rings inside its trunk.
But this technique doesn't work well in many species, because their bones are constantly growing, so they don't have well-defined growth rings. In addition, some scientists believe that these dinosaur fossils cannot tell us the age of the creature until it died.
According to BBC Science, some estimates ranging from 100 to 200 years for the lifespan of the largest herbivorous species were based on comparisons with crocodiles and turtles, which have much slower metabolisms. The consensus now is that the dinosaurs Apatosaurus and Diplodocus, for example, may have lived only 70 or 80 years, roughly equivalent to the age of an elephant today.
However, the life expectancy of animals is related, in part, to their body size and, in part, to the type of metabolism they have, as well as their diet and environment. Dinosaur lifespans may have ranged from tens to hundreds of years, but these estimates, based on the life spans of cold-blooded animals, would be very long if dinosaur metabolisms were more similar to those of modern birds and mammals.
Since more recent evidence suggests that many dinosaurs had metabolisms similar to those of birds, they probably did not have the same relative longevity as larger reptiles. It is possible, then, that sauropod dinosaurs lived between 50 and 100 years, larger theropods a little less than that, and smaller dinosaurs could live to be about 10 or 20 years old. So the conclusion, according to many researches, is that the average lifespan of dinosaurs was 20 to 30 years.
