Some dinosaurs could rise like giants until they grew too big

Some dinosaurs could rise like giants until they grew too big Some young sauropods could stand tall like giants, using their powerful hind legs to feed, fight, and impress. - Date: - July 20, 2026 - Source: - Fundação de Amparo à Pesquisa do Estado de São Paulo - Summary: - Two elephant-sized South American sauropods were unusually well built for standing on their hind legs. Digital tests showed that their robust femurs handled the enormous forces better than those of larger species, especially while the dinosaurs were young.

The upright pose may have helped them reach treetops, frighten predators, or impress potential mates. - Share: Some long-necked dinosaurs may have been far more capable of standing upright than their enormous bodies suggest. About 66 million years ago, two South American sauropods could rise onto their hind legs and remain there for relatively long periods, especially when they were young.

This ability may have helped them reach leaves high in trees, appear more intimidating to predators, attract mates, or reproduce. The dinosaurs, Uberabatitan from Brazil and Neuquensaurus from Argentina, were modest in size compared with the largest sauropods. Even so, they were roughly comparable to modern elephants.

Adult Uberabatitans may have grown as long as 26 meters, making them the largest dinosaurs known from Brazil. New research suggests that their ability to stand upright declined as they grew. Younger animals were better able to support themselves on two legs, while adults probably experienced much greater strain because of their increasing weight.

The findings come from a study supported by FAPESP and published in the journal Palaeontology. The international research team included scientists from Brazil, Germany, and Argentina. Testing Dinosaur Bones With Engineering Tools To investigate how sauropods handled the forces involved in standing upright, the researchers turned to a computational method commonly used in engineering.

Their goal was to estimate how much stress gravity and body weight placed on the femur, or thigh bone, when each dinosaur shifted its weight onto its hind legs. "Smaller sauropods like these had a bone and muscle structure that allowed them to stand more easily and for longer on their two hind legs. Larger ones were probably also able to stand, but for a shorter time and with less comfort, since the position caused a lot of stress on the femur," summarizes Julian Silva Júnior, a postdoctoral researcher at the School of Engineering of São Paulo State University (FEIS-UNESP) in Ilha Solteira, Brazil.

Silva Júnior is the study's first author. He carried out the research during an internship at the University of Tübingen in Germany with a scholarship from FAPESP. The team created digital reconstructions of the femurs of seven sauropod species.

The selected dinosaurs represented different evolutionary branches, body sizes, and anatomical features. Their models were built from fossils preserved in natural history museums around the world. Simulating the Forces of Standing Upright The scientists used finite element analysis (FEA), a method that breaks a structure into many small sections and calculates how each part responds to pressure, weight, heat, or other forces.