How long did dinosaurs live?

Dinosaurs left a lot of information in fossils. We know how they defended themselves, what they ate, how they died. As it turned out, they also left behind clues about how old they were when they died. Scientists say these clues are “growth rings” in fossilized bones. These rings, which accumulate like tree rings, have only been discovered in the last few decades and show that although they sometimes reached very large sizes, most non-avian dinosaurs did not live very long.

For example, one of the most complete T. rex specimens ever found died at the age of 28, as evidenced by its growth rings. Herbivorous platypus dinosaurs appear to have lived only ten or twenty years. Such a young age initially surprised paleontologists. It is conceivable that at least some dinosaurs must have lived so long because they were so large. Of course, scientists thought so too.

Large modern animals are generally long-lived. African bush elephants (Loxodonta africana), the world’s largest land animals, can live up to 70 years, and bowhead whales (Balaena mysticetus) can live up to 200 years.

But dinosaurs are a completely different story. A thin section of an animal bone has a series of parallel lines resulting from the outward growth of the bone.. A new line is formed each year, so counting these lines provides an accurate estimate of the animal’s age. These stripes are created due to annual changes in the way animals grow. Warm weather and abundance of food in spring and summer means animals have enough nutrients, allowing them to grow faster. However, growth slows in winter when the weather gets cold and food becomes scarce. This growth retardation manifests itself as lines between the bone layers.

However, this growth measurement technique has some complications. One of these relates to the marrow cavity, which is the room inside the bone that produces marrow. When the bone grows, the bone marrow cavity grows with it, so erases some early growth rings in this extension. To get around this problem, researchers can place bones from smaller individuals of the same species over missing lines from larger individuals to help estimate the potential total.

Another complication is the type of bone. Some bones are better suited to detecting growth rings than others. “Bones like ribs or fibulae that are not subjected to heavy loads or weight tend to have cleaner growth records.”scientists say.

Although dinosaurs did not live as long as some of today’s large animals, there are some similarities between them. Example, Large animals tend to live longer than small ones. The same goes for dinosaurs. Sauropods are a group of long-necked leaf-eaters that include the largest dinosaurs that ever lived and probably had the longest lifespan of all dinosaurs. The oldest known sauropods lived to be about 60 years old.

In contrast, the 50-kilogram Stenonychosaurus (Stenonychosaurus inequalis) reached its maximum size in only three to five years and probably did not live long after that.

The reason for short life

• There are various ideas as to why dinosaurs were so short-lived. Perhaps their metabolism or chemical processes in the body, including the conversion of calories into energy, played a role.. Some dinosaurs were at least partially warm-blooded and had incredibly fast metabolisms for reptiles, which could have led to rapid growth and early death.
• this too It may be related to reproduction. Many dinosaurs produced very large egg flocks, meaning they produced large numbers of offspring in a short time. So if nature produced a large offspring, it didn’t need an adult. Long-lived mammals like elephants and whales reproduce more slowly, so natural selection rewards them with longer lives so they have time to have more babies.

However, this hypothesis is not perfect. For example, Galapagos tortoises can lay large numbers of eggs but still live to triple-digit ages; Therefore, the birth of many offspring at a time does not always indicate a shorter lifespan.

After all, we still don’t understand why non-avian dinosaurs died out so early, but we at least know roughly how long they lived.