Discovery confirms theropod capable of swimming in China's Sichuan Province

Archaeologists said they have discovered the trackway of a swimming theropod in southwest China's Sichuan Province, helping to confirm that non-avian theropods were capable of swimming.

The research was conducted by both domestic and international archaeologists in Zhaojue County, Sichuan.

The trackway was found on the same surface as a typical walking trackway of a sauropod. Both occurrences were the first to be reported in China, and the swimming tracks are the first well-preserved example of a Characichnos trackway from China, said Xing Lida, an archaeologist with the China University of Geosciences.

Additionally, a theropod walking trackway and several ornithopod walking trackways were found in the same horizon, the archaeologists said.

The ornithopod trackways show a parallel orientation, suggesting gregarious behavior among the trackmakers, which may have been iguanodontiforms and/or hadrosauriforms, according to the archaeologists.

"Similar tracks were found in Chicheng County, Hebei Province, but were from a rare, indistinct specimen," said Xing, adding that the tracks found in Sichuan Province definitely indicate that carnivorous theropods were capable of swimming.

Although such a specimen is extremely rare, carnivorous theropods were long believed to averse to water until archaeologists in the United States found evidence that they were capable of swimming in 2007, the archaeologists said.

"The height of the trackmaker's hip is about 0.9 meters, which is the same as the depth of water," said Zhang Jianping, another archaeologist with the university.

The presence of both theropod swimming tracks and theropod walking tracks suggests that the depth of the water fluctuated within a distinct time span, Zhang added.

The findings were published in the Tuesday edition of the Chinese Science Bulletin.