Named By: Samuel Paul Welles - 1943.
Classification: Chordata, Reptilia, Sauropterygia, Plesiosauria, Elasmosauridae.
Species: F. drescheri (type).
Size: Estimate around 10 meters long for the holotype, but possibly up to 12 meters when fully grown.
Known locations: USA - California - Moreno Formation.
Time period: Maastrichtian of the Cretaceous.
Fossil representation: Partial skeleton of a juvenile/subadult.
was a late Cretaceous era elasmosaurid plesiosaur
that seems to have
the signature feature of this group of a very long neck proportionately
greater than in earlier and more primitive plesiosaur forms. Like
with these other genera, Fresnosaurus was
probably a specialist
hunter of fish and soft bodied cephalopods like squid.
Fresnosaurus is not the only plesiosaur from the Moreno Formation with others including Morenosaurus, Aphrosaurus and Hydrotherosaurus. Additionally not only have all of these plesiosaurs come from the Moreno Formation, but they were all described by Samuel Paul Welles and all in 1943. Other marine reptiles to be discovered in the Moreno Formation include the mosasaurs Plotosaurus and Plesiotylosaurus, as well as the remains of marine turtles.
The name Fresnosaurus is a reference to Fresno County in California, while the type species name F. drescheri is in honour of Arthur Drescher.
- Elasmosaurid plesiosaurs with description of new material from California and Colorado. Memoirs of the University of California 13:125-254. - S. P. Welles - 1943.