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Image Gallery: Photos Reveal Prehistoric Sea Monster

Menacing Jaws

prehistoric ichthyosaur sea monster, illustration,

(Image credit: John Weinstein, The Field Museum, Chicago)

A jaw full of 5-inch, knife-edged teeth let this newly unearthed ichthyosaur, called Thalattoarchon saurophagis, tear into prey its same size and larger, researchers say. The species swam in what is now Nevada some 244 million years ago.

Snagging a Snack

prehistoric ichthyosaur sea monster, illustration,

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

The giant ichthyosaur ruled the oceans some 244 million years ago. Here's what it may have looked like seizing a meaty snack.

Lizard-Eating Ruler

prehistoric ichthyosaur sea monster, illustration,

(Image credit: Nicole Klein, Universität Bonn, Germany)

This is what the jaws of Thalattoarchon saurophagis (whose name means "lizard-eating ruler of the sea") looked like when they were discovered by Field Museum preparator Jim Holstein on July 24, 1998. The photograph was taken seven years later in preparation for excavation.

Ichthyosaur Skull

prehistoric ichthyosaur sea monster, illustration,

(Image credit: Nicole Klein, Universität Bonn, Germany)

The predator was a member of the ichthyosaurs, marine reptiles that evolved from land reptiles just as modern whales did from land mammals and which cruised the oceans for 160 million years, going extinct about 90 million years ago. Here, the back of the skull and neck during the excavation of the ichthyosaur skeleton in 2008. The bones are encased in a large nodule, the pieces of which were numbered for later reassembly.

Steep Canyons

steep canyons where scientists found ichthyosaur fossils

(Image credit: Nicole Klein, Universität Bonn, Germany)

A view down Favret Canyon with University of Bonn preparator Olaf Dülfer. The new ichthyosaur came from the beds in the background above the steep canyon walls.

Prey-Slicing Teeth

tooth crown of ichthyosaur

(Image credit: Nicole Klein, Universität Bonn, Germany)

Tooth crown of Thalattoarchon as seen in the field. The shape of the crown with its two cutting edges indicates that this ichthyosaur was a meat eater, using its tteth to seize and slice prey.

Plaster Jacket

prehistoric ichthyosaur sea monster, illustration,

(Image credit: Jörg Fröbisch,Museum für Naturkunde, Berlin, Germany)

Paleontologist Nadia Fröbisch preparing a plaster jacket for the fossil of the new ichthyosaur in the field in Nevada.

Upturned Eyeball

prehistoric ichthyosaur sea monster, illustration,

(Image credit: Jörg Fröbisch, Museum für Naturkunde, Berlin, Germany)

This is the right side of the skull during preparation in the Field Museum labs showing the upturned eyeball and the huge teeth in front of it.