Bizarre Fossil Sea Monster Emerges From Argentine Desert

Top Predator Feasted on Marine Reptiles and Other Sea Creatures

WASHINGTON--A large fossil sea monster with a head like a carnivorous dinosaur and a tail like a fish’s has been discovered in Argentina’s Neuquén Basin at the foot of the Andes. The scientist who found the specimen is calling the fierce-looking animal “Godzilla.”

“The recent film monster Godzilla frightened the people of New York City, but our Godzilla terrorized creatures in the Pacific Ocean,” said expedition leader Zulma Gasparini of Argentina. “We are calling him the ’chico malo’ -- ’bad boy’” of the ocean.

The animal, a crocodyliform, was a predator capable of gobbling reptiles and other large sea life it encountered in its Pacific Ocean home some 135 million years ago. The species, known previously from only a few fossil fragments, is introduced Nov. 10 by the journal Science, as part of its ScienceExpress Web site, and appears on the December 2005 cover of National Geographic magazine. The research was partly funded by the National Geographic Society.

Crocodyliforms are a group that includes today’s crocodiles and their extinct relatives. “This animal was one of the latest members of its family (Metriorhynchidae) and certainly the most bizarre of all marine crocs,” said Diego Pol of The Ohio State University, a coauthor of the Science paper. “Nobody really had expected to find these features in a marine croc.”

Godzilla, whose scientific name is Dakosaurus andiniensis, was brought to life through discovery of an intact skull and some vertebrae in the fossil-rich desert region of Neuquén; a second, less complete specimen also was found. Gasparini, professor of paleozoology at Argentina’s Universidad Nacional de La Plata, led the 1996 expedition, and team members Sergio and Rafael Cocca found the skull.

“This animal’s anatomy is really a contrast with that of the other sea crocs that developed during the Jurassic,” Gasparini said.
Instead of a long, thin snout typical of most marine crocs, the fossil’s snout is very short and high. Instead of numerous, thin teeth, the animal has teeth that are large, powerful and serrated -- and seem to belong in a dinosaur’s mouth.

“This was a top predator that probably was 12 feet long and swam around using its jagged teeth to bite and cut its prey, like dinosaurs and other predatory reptiles did,” Pol said.

Dakosaurus’ anatomy bore little resemblance to that of today’s crocs, which divide their time between land and water. In place of legs, Dakosaurus had four paddle-like limbs, used mostly for stability. A vertically oriented, fish-like tail propelled the animal through the water. Dakosaurus would have regularly swum to the sea’s surface to gasp oxygen and then retreat into the Pacific, which was 600 to 750 feet deep and devoid of oxygen near the bottom.

Dakosaurus was only one of the “sea monsters” that cavorted in the world’s oceans 250 million to 65 million years ago. Shallow seas and a lack of significant marine predators created new niches for many reptiles that had developed on land, National Geographic’s December issue reports. They included such beasts as a Loch Ness monster-like plesiosaur, with a 20-foot-long neck, and giant ichthyosaurs that may have reached 75 feet in length.

Geologist Luis A. Spalletti of the Universidad Nacional de La Plata coauthored the Science paper with Gasparini and Pol. Gasparini’s research was funded by Argentina’s National Council of Scientific and Technical Research, the Agencia Nacional de Promócion Cientíifica y Tecnológica, and, since 1989, the National Geographic Society.

Beginning mid November, National Geographic magazine’s Web site, www.ngm.com, will feature 3-D models of ancient sea monsters that will allow users to maneuver them and watch, via action-packed animations, two of the creatures hunt their prey.

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Barbara Moffet

National Geographic Society

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