A team of US scientists has found out that the offspring of enormous carnivorous dinosaurs like the Tyrannosaurus rex, which grew from the size of house cats to towering monsters, reshaped their ecosystems by becoming apex predators mainly thanks to their size.
The study was recently published in the journal Science. It helped answer a mystery regarding the 150-million-year rule of dinosaurs – Why most dinosaurs consisted of huge specimens, in contrast to the diversity we see today.
Kat Schroeder, a graduate student of the University of New Mexico, and leader of the research stated:
“Dinosaur communities were like shopping malls on a Saturday afternoon, jam-packed with teenagers […] They made up a significant portion of the individuals in a species and would have had a very real impact on the resources available in communities.”
Even considering the limitations of the fossil record, the truth is that dinosaurs were not diverse at all. There are over 1,500 known species, compared to the currently existing tens of thousands of modern mammalian and bird species.
Some scientists believe that since even the most gigantic dinosaurs begin life as tiny hatchlings, they may have used different resources as they grew in size, filling the space in ecosystems where smaller exemplars would flourish otherwise.
The researchers used a statistical method of treating juveniles as individual species, squaring them away from medium-sized carnivores’ observed gaps.
“I think we’re shifting a little bit more towards understanding dinosaurs as animals as opposed to looking at dinosaurs as just cool rocks, which is where palaeontology started and has been for a long time,” Schroeder said.