For years, the depiction of the Tyrannosaurus rex as a swift predator dominated popular culture. However, new research suggests that these dinosaurs were not as fast as once thought. "After really sort of ground truthing, figuring out how much bone and tissue needs to be on the animal to reach a particular speed with enough power, people realized Tyrannosaurus probably didn’t run more than 20, 25 miles per hour," explains Jack Tseng, a vertebrate paleontologist at UC Berkeley.

Tseng's work involves studying the physical structure of organisms and their environmental functions. By examining living bipedal birds like chickens and ostriches, paleontologists have revised their understanding of T. rex's speed capabilities. Without access to soft tissues such as muscles from extinct animals, scientists use modern birds and other animals to draw parallels.

Recent advances in imaging technology and global research collaboration have significantly expanded knowledge about prehistoric life, reshaping public perceptions of dinosaurs' appearance and behavior. Tseng notes that this research provides insights into imagining Earth's future millions of years ahead.

At UC Berkeley's Department of Integrative Biology, where Tseng is an associate professor, he teaches courses on paleontology including Life During the Age of Dinosaurs. He discusses hypotheses on how sauropods managed oxygen intake through their long necks by comparing them to high-speed animals like peregrine falcons and cheetahs.

Modern findings indicate many dinosaurs had feathers—an idea supported by fossil discoveries showing feathered tyrannosaurs. "In some paleoartistic reconstructions, you will see furry T. rex," says Tseng. This challenges traditional views of dinosaurs resembling large lizards with scaly skin.

Furthermore, there is debate over whether T. rexes were scavengers rather than hunters based on tooth marks found on fossils of potential prey. Tseng has explored this through studies on juvenile Tyrannosaurus rex bite mechanics.

Paleontology is unique in its documentation within popular media like children's books which reflect evolving scientific understanding over time. "If you look at books from 50 years ago, they postured dinosaurs very differently from the way we do it today," Tseng observes.

He emphasizes paleontology's relevance in addressing current issues like climate change by studying past extinctions recorded in fossils: "The questions we ask...have to do with how different species sometimes survive when others go extinct."

Looking forward, Tseng envisions paleontology continuing beyond humanity's existence—potentially practiced by another species analyzing our fossil record: "Even though...the human species is the first one to do science...we might not be the last."