Titanosaurs were among the largest dinosaurs in history, but a new study suggests that their babies were unusually small, and quite similar in size to human babies.
Based on previous fossils, titanosaurs grew as heavy as 77 tons and were up to 49 feet long and 15 feet tall, not including their necks and heads. But based on the fossil of a baby Rapetosaurus krausei, which is a species of titanosaur, the animal’s babies were remarkably much smaller than what you’d expect from a dinosaur of its size. After all, modern animals such as blue whales and elephants, two of the largest animals in existence today, have much larger and heavier babies.
“This tiny titanosaur lived around 67 million years ago, at the very end of the age of dinosaurs in the Latest Cretaceous,” said lead author Kristina Curry Rogers of Macalester College in St. Paul, Minn., speaking to Discovery News. “At the time it died it was just a few weeks old, and was about the size of a golden retriever, though with a long, thin neck and a tiny skull, and a long slender tail.”
Rogers noted that titanosaur babies were born at about 6 to 8 pounds, and grew to about 70 pounds after a few weeks. But what was also interesting was how the babies were quite independent from the moment they hatched from their eggs. These babies were apparently able to walk on their feet soon after hatching. While some of them remained in their mothers’ nests for some time after they hatched, many were able to run around independently at that early point in their lives.
“Rapetosaurus babies were ridiculously overengineered,” said Sarah Werning of Des Moines University, who was not involved in the study. “In other words, they laid the foundation for a skyscraper under a single-story home, knowing they were going to keep building.”