In Images: The Tracks of an Ancient Sea Monster

Trackmarks uncovered

nothosaur tracks being excavated — (Image 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

images of nothosaur track — (Image credit: © Chengdu Center of China Geological Survey)

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

Rowing limbs

illustration of a nothosaur — (Image credit: Original artwork © Brian Choo, 2014)

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

Tasty snack

Live lobsters caught in Bar Harbor, Maine. — (Image 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

prehistoric ichthyosaur sea monster, illustration, — (Image 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

illustration of a mosasaur — (Image 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.

Tia is the managing editor and was previously a senior writer for Live Science. Her work has appeared in Scientific American, Wired.com and other outlets. She holds a master's degree in bioengineering from the University of Washington, a graduate certificate in science writing from UC Santa Cruz and a bachelor's degree in mechanical engineering from the University of Texas at Austin. Tia was part of a team at the Milwaukee Journal Sentinel that published the Empty Cradles series on preterm births, which won multiple awards, including the 2012 Casey Medal for Meritorious Journalism.