Abstract Expressions: Dr. Kristi Curry Rogers

Researcher: Dr. Kristi Curry Rogers, DeWitt Wallace Professor of Biology and Geology

Subject: Growth patterns among the earliest-known dinosaurs

Abstract: Famous dinosaurs, like the long-necked giant sauropods, duck-billed hadrosaurs, and fearsome carnivores like T. rex grew up fast, but all of these icons evolved millions of years after dinosaurs originated. When dinosaurs first evolved, different groups of reptiles ruled, many of which are more closely related to living crocodiles than to dinosaurs. Near the end of the Triassic Period around 230 million years ago, dinosaurs became more common. Scientists have long surmised that uniquely rapid growth patterns may have helped them rise to dominance. Until now, exactly how fast the very first dinosaurs grew compared to other animals has remained a mystery.

In a groundbreaking new study published in the journal PLOS ONE, lead researcher Kristi Curry Rogers, DeWitt Wallace Professor of Biology and Geology, and her colleagues (including Ray Rogers, DeWitt Wallace Professor of Geology) offer a first-ever look at growth patterns among the earliest-known dinosaurs. Their results pave the way for paleontologists to better understand how dinosaurs came to be the ultimate survivors of multiple mass extinctions, and eventually rose to rule the earth for hundreds of millions of years.

Takeaway: “We’ve always wanted to know something about how and when dinosaurs may have originated some of their most special characteristics, and which of their many traits might have been critical to their survival,” says Curry Rogers. “One feature that is often thought to set dinosaurs apart is their rapid growth rates. Studies of many species reveal that dinosaurs, as a group, grew more like mammals and birds than like reptiles. But when did dinosaurs first evolve these rapid growth patterns?

“In our study, we took a look at growth in the oldest known dinosaurs, as well as a suite of non-dinosaurian reptiles living at the same time and in the same ecosystem. We wanted to know whether at this earliest moment of dinosaur evolution, the first dinosaurs grew any differently than their non-dino sidekicks. It turns out that, at the start, there was a lot of overlap in the way all of these animals grew! When dinosaurs first arrived on the scene, their growth rates really didn’t set them apart, but were just one of a suite of new adaptations that helped dinosaurs survive and thrive in a world decimated by extinction.”