In a study published in April 2024, researchers analyzed the growth rates of the earliest dinosaurs and other animals living in the Mesozoic era. They found that dinosaurs exhibited rapid growth rates, a factor that likely contributed to their success in the ecosystem. The researchers conducted a histological analysis of fossilized leg bones from the Ischigualasto Formation in Argentina, dating back to 231-229 million years ago. The fossils included early dinosaurs, non-dinosaur reptiles, and an early relative of mammals.
The results showed that most of the species examined, including early dinosaurs and non-dinosaur reptiles, had elevated growth rates similar to modern-day mammals and birds. This suggests that fast growth was a common trait among animals in the Triassic period. The researchers point out that while rapid growth may have been important for the success of dinosaurs, it was not unique to them. Other lineages of animals were also evolving with elevated growth rates during this time, indicating that it was only one part of the story of dinosaurs’ eventual global prosperity.
The study highlights the significance of rapid growth rates in the evolution of early dinosaurs and their success in the Mesozoic ecosystems. The researchers note that future studies could further explore this topic by examining a wider variety of ancient animals from additional early Mesozoic fossil sites. The findings suggest that rapid growth was a shared trait among the diverse array of animals living 230 million years ago, including dinosaurs and non-dinosaur reptiles.
The researchers emphasize that during the Triassic period, dinosaurs were not the only fast growers, as many of their non-dinosaur counterparts also exhibited similar growth rates. This challenges the idea that rapid growth was a unique feature of dinosaurs that contributed solely to their success. Instead, it suggests that other animals evolving with elevated growth rates may have played a role in shaping the ecosystems of the time. The study sheds light on the dynamic evolution of growth strategies among early Mesozoic animals and their impact on the development of diverse ecosystems.
