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Why did some dinos get so big?

By the time non-avian dinosaurs went extinct, plant-eating sauropods such as the Brontosaurus had grown to gargantuan proportions. Weighing as much as 100 tons, the long-neck behemoths were the largest land animals to ever walk the Earth. How they grew so large from ancestors that were small enough to be found in a modern-day petting zoo has remained a mystery. A new, in-depth anatomical description of the best-preserved specimens of a car-sized sauropod relative from North America could help paleontologists unravel the mystery. The dinosaur -- called Sarahsaurus aurifontanalis -- lived about 185 million years ago during the Early Jurassic epoch. It could hold important clues about sauropods' size because it belonged to the dinosaur grouping that preceded them. Its evolutionary placement combined with the exquisite preservation of the specimens is giving researchers a detailed look into its anatomy and how it relates to its larger cousins.

Visit Website | Image credit: The Jackson School Museum of Earth History Vertebrate Paleontology Collections/The University of Texas at Austin