Name:
Hydrotherosaurus (Greek for "fisherman lizard"); pronounced HIGH-dro-THEE-roe-SORE-us
Habitat:
Shores of western North America
Historical Period:
Late Cretaceous (70-65 million years ago)
Size and Weight:
About 40 feet long; weight unknown
Diet:
Fish
Distinguishing Characteristics:
Small head and exceptionally long neck
About Hydrotherosaurus:
In most ways, Hydrotherosaurus was a typical plesiosaur, a type of aquatic reptile with a long, flexible neck and relatively small head. What made this genus stand out from the pack were the 60 vertebrae in its neck, which were shorter toward the head and longer toward the trunk.
Although it may have lived elsewhere, Hydrotherosaurus is known mostly from a single complete fossil found in California, which contains the remnants of this creature's last meal. Nestled inside this skeleton, paleontologists discovered gastroliths ("stomach stones"), which likely helped anchor Hydrotherosaurus to the sea bottom, where the food was.
