Theropod Dinosaurs Could Swim Like Crocodiles: Mᴀssive Bolivian Track Site Reveals Thousands of Swim Tracks

Paleontologists have uncovered the world’s largest concentration of dinosaur swim tracks, proving that bipedal theropods — the group that includes Tyrannosaurus rex and its relatives — were skilled swimmers capable of paddling through shallow waters much like modern crocodiles.

The record-breaking discovery comes from the Carreras Pampa track site in Torotoro National Park, central Bolivia. Published December 3, 2025, in PLOS One, the study by Raúl Esperante and colleagues documents nearly 18,000 tracks across an ancient coastal plain: 16,600 normal footprints plus 1,378 swim tracks and several tail-drag traces. This single 80,570-square-foot exposure contains the highest number of continuous dinosaur swim trackways ever recorded.

Most tracks belong to theropods. The swim traces show distinctive comma-shaped or straight grooves made when the animals, buoyed by water, scratched the lake-bottom sediment primarily with their middle toe while the outer toes and heels left only faint impressions. The longest continuous swim trackway stretches over 130 metres, demonstrating sustained swimming ability rather than brief wading.

These traces, formed in the Late Cretaceous when the area was a fluctuating shoreline, reveal that theropods regularly entered deeper water and propelled themselves forward with coordinated limb strokes. The behaviour mirrors how crocodiles use their limbs and tail for propulsion in shallow or slow-moving water.

The find dramatically expands our understanding of dinosaur locomotion and ecology. Far from being strictly terrestrial, many theropods were versatile enough to swim across rivers, lakes, and coastal shallows — a skill that would have helped them hunt, escape predators, or traverse fragmented landscapes.

Housed in Bolivian insтιтutions and now the focus of international research, Carreras Pampa stands as the ultimate “dinosaur freeway” and swimming pool combined. After 66 million years, these footprints finally prove that some dinosaurs were as comfortable in water as they were on land.