Trackmarks uncovered

Trackmarks uncovered

Credit: © Chengdu Center of China Geological Survey

In 2009, researchers uncovered track marks made by Triassic era marine reptiles. Here, students and farmers help excavate the track marks made by paddle-limbed creatures called nothosaurs 245 million years ago.

Long-standing debate

Long-standing debate

Credit: © Chengdu Center of China Geological Survey

The tracks could help resolve a long-standing debate: how nothosaurs swam.

Rowing limbs

Rowing limbs

Credit: Original artwork © Brian Choo, 2014

The new analysis shows the nothosaurs, like the Lariosaurus shown here, probably used a rowing motion.

Tasty snack

Tasty snack

Credit: Natalia Bratslavsky | Shutterstock

Nothosaurs probably ate the lobster and fish that dwelled on the seabed surface, and their paddle-like rowing dredged them up from the soupy sediments.

Ancient sea monster

Ancient sea monster

Credit: Art by Raul Martin, © 2013 National Geographic Magazine, Reproduced with permission (ONE-TIME USE)

The researchers ruled out other sea creatures, such ichtyosaurs and other marine reptiles based on size and anatomy.

Other monsters

Other monsters

Credit: Tibor Pecsics

Nothosaurs could range from 13-feet long to a measly 2-feet long. For comparison, mosasaurs that terrorized the sea during the Cretaceous Era (pictured here) were 20 feet (6 meters) long.