Nevada: Shonisaurus popularis (state fossil)
Nevada: Shonisaurus popularis (state fossil)
Nevada 225 million years ago could not have been more different than it is today. During the Late Triassic Period, the state hosted the shoreline of a vast, shallow sea and lay along what was then the western edge of North America. One of the denizens of this sea was the ichthyosaur Shonisaurus popularis, now designated the state fossil.
Ichthyosaurs (a name meaning "fish lizards") were predatory reptiles that filled the same ecological niche as -- and quite resembled in body form -- the dolphins of today, only many of them were much larger. Shonisaurus was around 50 feet long and may have weighed 40 tons. It preyed on the fish and ammonites (extinct, coiled cephalopods) that were abundant in the oceans of that time, grasping them with its pointed mouth full of about 200 sharp, conical teeth. Ichthyosaurs as a group were very successful throughout the Mesozoic Era, becoming extinct near the end of the Cretaceous for unknown reasons probably unrelated to the extinction of the dinosaurs.
The bones of Shonisaurus are abundant near the ghost town of Berlin, a thriving mining camp about a century ago. Miners discovered the first bones, and sometimes used the flattened vertebrae (backbone segments) of Shonisaurus for dinner plates and decorations. The first nearly complete skeleton was found in 1928, and soon brought to the attention of scientists, who came to excavate the site. They found parts of 37 ichthyosaurs together in a small area of the Luning Formation. Various explanations for this abundance of bones have been proposed, with the idea that they were collected by current eddies in a shallow lagoon being the most widely accepted today. The area is now preserved as Berlin-Ichthyosaur State Park.
Shonisaurus popularis became the Nevada state fossil in 1977.
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