Paleontologists have found that predatory dinosaurs of the Cretaceous know how to swim. This is indicated by traces of their claws, preserved at the bottom of an ancient river.
Details of Canadian paleontologists from the University of Alberta, were published in the scientific journal Chinese Science Bulletin.
Many types of dinosaurs, according to some experts, a significant part of their time in the water. It is in particular the sauropods - large herbivorous dinosaurs with four legs and a long neck. But the authors of the work found that theropods - bipedal carnivorous dinosaurs could also be moved in the aquatic environment.
This conclusion scientists came by studying the ancient river bed, which is located in the Chinese province of Sichuan. The river flows through the area in the first half of the Cretaceous period - about 100 million years ago. Cracks in mud sediments found by researchers at the bottom of the river, indicate that the seasonality in the time characterized the climate of the region, and partially dried up river during dry periods.
The researchers have named the river "Highway dinosaurs", as in the mud on the river bottom dinosaurs left a lot of their tracks. Among the huge sauropod footprints was discovered by paleontologists 15-meter track. According to the analysis, it left floating on the river predatory dinosaur, touching the bottom of the hind limbs.
"Sailing on the river, with his dinosaur claws periodically touching the bottom," - said one researcher Scott Persons. The scientists also suggest that swimmers could be early tyrannosaurs or Sinocalliopteryx - predatory dinosaur, who lived in present-day China in the early Cretaceous period.