How Were Dinosaurs so Big? And Why Are Mammals so Small?

Dinosaurs are beloved around the earth even though they are sort of extinct. I say “sort of” because only the non-avian birds died in the kt extinction event. The avian dinosaurs- aka birds- are all around us and have flourished, with an estimated 10,000 species. One reason they’re loved so much is because they were HUGE. and that is an understatement. So let’s see how they reached these giant sizes.

How Big?

Dinosaurs, and sauropods in particular, reached sizes never before seen before and after dinosaurs. Animals such as the Argentinosaurus huinculensis could reach up to 90 tons (higher estimates), and reach 39–46 feet in hight. More famous sauropods, like Brachiosaurus altithorax could reach 40–45 feet, still be half the weight. For reference that’s as tall as a T-rex put vertically.

Bones

Dinosaurs had pneumatic bones which is a fancy way of saying hollow bones. This might sound bad. but it wasn’t really hollow- it was like Swiss cheese. This was strong as (if not more) than our bones. But this does help in someway. Weight reduction. This makes the bones lighter and Therefore, making it easier to hold up more flesh instead of devoting so much more energy to holding up the extra weight of the bones.

Food

An average African elephant already 270 kilograms of food each day. That would mean that sauropods would have to eat around 2.7 tons of food. That sounds crazy becaue it is! but it’s the only way that the math works. But more recent studies say that they ate around as much as an elephant. Maybe a little more. There were a few reason why this worked:

Sauropods and dinosaurs were so large, and mammals so small because of another reason. Gigantothermy. This isn’t my opinion- bone histology indicates “warm bloodedness”. This saves food because many mammals have to use a lot of food to keep them warm blooded. So dinosaurs were just warm blooded just because they were! and Mammals are warm blooded because they have “biological furnaces” in their bodies. These furnaces are expensive, in the sense that they use a lot of calories. Dinosaurs don’t have to spend so much on just heating themselves up so they can just put that energy into growing.

Air Sacs

With a lower appetite also came another way of breathing. like in birds dinosaurs likely had the air sac system. This was a system with chambers which insured that fresh oxygen was always flowing through their lungs. This is more advanced form of breathing than what us mammals use. This is a better because it got more oxygen in and used it. Were as we, mammals, breath in and out, which is less efficient because while we exhale, dinosaurs were inhaling and exhaling.

Conclusion

Dinosaurs had lots of things that seem impossible! Biologists say that an elephant is the largest an animal can get on land. Yet in the late Jurassic, on the same earth, (well, it would have been different in that the continents were different sizes and shapes along with the climate being different) there were 40 ton behemoths stomping the ground. Dinosaurs break everything we know about how big, strong, cool, and just out right crazy, an animal can get. Dinosaurs are the wonders of the prehistoric world.