Question: Why did dinosaurs evolve to be smaller?
Answer: It had to do with survival, metabolism, and climate
Why did dinosaurs evolve to be smaller?
This question has brought a lot of debate, and with that, many more theories and hypotheses as answers to why dinosaurs didn’t get bigger but got smaller. If we were to list all the hypotheses that have come out, you would be reading for days. But there was a common denominator with these theories, and it had to do with survival, metabolism, and climate.
First, dinosaurs never started as giant beings but were very small; they came from Archosaurs, and by the middle of the Triassic period, they had developed into the dinosaurs we know today and were quite dominant from the Jurassic.
The theory which made sense to me was based on dinosaurs’ metabolism and how climate is also a contributing factor. Sauropods, for example, did not chew their food; they just picked and swallowed, and their stomachs would grind the food over weeks, releasing the energy and nutrients necessary to fuel their large bodies.
This manner of eating has been known to make creatures bigger; even with us humans, when you eat a lot, you are more likely to gain a few pounds. So when this food stock started to get lower because of climate changes, their bodies changed too, and this shrinkage in size was not instant; it took about 50 million years.
It was pretty hot during the Mesozoic era, so plants were abundant for herbivorous dinosaurs preying on carnivorous dinosaurs. You understand how plants, herbivores, and carnivores helped each other get bigger. And dinosaurs lived in a time when there were no preservatives or harmful chemicals in their food so that they could get bigger. Entering the Cenozoic era, the climate got cooler, and there was an ice age; this forced avian dinosaurs to adapt, so their size changed with time.