Researchers at the University of Bristol have made a surprising discovery that sheds new light on the early evolution of giant sauropods. The team unearthed evidence of a previously unknown ancestor – Thecodontosaurus antiquus – that defied expectations with its small size, bipedal stance, and surprising agility.
Sauropods, the massive, long-necked herbivores that dominated the Jurassic period, have captivated scientists and the public alike. However, their evolutionary path remained shrouded in mystery. This new finding, published in Royal Society Open Science, reveals an unexpected twist in their ancestry.
Imagine a dinosaur no bigger than 30 centimeters tall when standing – a stark contrast to the colossal sauropods we know. Thecodontosaurus antiquus, living about 200 million years ago during the Late Triassic, resembled a miniature velociraptor more than its lumbering descendants.
Examination of the remarkably well-preserved fossil revealed key features that point to a nimble and swift creature. The researchers discovered that Thecodontosaurus’ hind legs were built for running, with strong muscles and adaptations for quick contractions, allowing it to outrun predators. Grooves and other features on its hip bones further suggest an ability to make sharp turns while running, aiding its escape strategy.
Interestingly, the forelimbs tell a different story. With much less muscle mass, they likely weren’t used for locomotion. Instead, the researchers believe these agile limbs served another purpose. Deep grooves in the bones suggest flexibility and reach, hinting at the ability to manipulate food with its hands, possibly reaching high into trees and grasping branches.
This discovery raises intriguing questions about dinosaur evolution. The upright posture of Thecodontosaurus contradicts the image of sauropods as quadrupedal giants. The research team believes this fossil might hold the key to understanding how smaller, bipedal dinosaurs transitioned to the four-legged giants we know so well.
Thecodontosaurus antiquus offers a unique window into the early days of sauropod evolution, revealing a surprisingly agile ancestor unlike its massive descendants. This finding underscores the diversity and adaptability of dinosaurs in their early development, rewriting our understanding of their evolutionary journey.