Newsmakers in the College of Natural Sciences

You Could Be Standing on a Dinosaur!

by Greg Liggett, Northern California Natural History Museum
From Inside Chico State, Dec. 7, 2006

People are surprised to learn that many fossils have been found throughout the North State, some from around, and even within, Chico.

It is understandable that most people are not familiar with the fossil heritage of this region, for few researchers have recently studied the topic and few museums locally display the exciting fossil finds (something that the Northern California Natural History Museum will address, at least in part).

The complex geology of our area is dominated by volcanic rocks, lava flows, and highly deformed rocks in uplifted mountain ranges—not the best rock types to look for fossils, to say the least. Sedimentary deposits are preserved around and among the harder, crystalline rocks, and it is in these deposits—accumulated in rivers, streams, lakes, and oceans—that fossils are typically preserved.

Before coming to Chico, I spent many years studying the fossils of the Great Plains, particularly those of central and western Kansas. There I decided not to concentrate on a particular fossil group or time period, as do most vertebrate paleontologists, but to focus on the big picture of the entire region. This allowed me to work with the giant marine lizards and bizarre fish that swam the Cretaceous sea and the large flying reptiles that soared above the dinosaurs, as well as the horses, camels, rhinoceroses, mammoths, lion-like cats, and bone-crushing dogs that roamed the plains after the seas there retreated, approximately 65 million years ago.

Moving to Chico provided the opportunity to study the fossils from the North State. I began by compiling a list of previously collected fossils and their localities. I was able to present the preliminary results of this review at the recent Society of Vertebrate Paleontology (SVP) annual meeting in Ottawa, Canada.

North State fossils from the Age of Dinosaurs (Mesozoic) include a variety of ichthyosaurs, strange marine reptiles that outwardly look like dolphins or whales but were actually reptiles and lived millions of years before the marine mammals they resemble. The ichthyosaur Shastasaurus, whose name means “lizard from Shasta,” is an example of a North State original, having been first found in Shasta County.

Another strange reptile group from that early time was the thalattosaurs. They, too, were adapted to an aquatic life by having elongate, flattened bodies and an overall body length of 2–3 meters (6.5–9.8 feet). This group is characterized by an unusual dentition, with conical teeth at the front end of their mouths and rounded crushing teeth in the back. They likely fed on shelled animals, crushing their shells with the rounded back teeth.

However, the vast majority of the fossil finds, from over 90 percent of the localities, are from after the Age of Dinosaurs. Vultures, owls, giant bison, camels, wolves, saber-toothed cats, mammoths, mastodons, rhinoceroses, giant ground sloths, and (my personal favorite) the giant short-faced bear are just a few of the fossil finds from our area.

There is much to be learned from these fossils. Many thousands of specimens were collected in the early 20th century from caves around Mt. Shasta, including Samwel Cave and Potter Creek Cave. After their initial collection and a few published reports, this wealth of fossil material has gone mostly unstudied in museum collections. The specimens are waiting patiently for their secrets to be revealed.

At the SVP meeting, I met many people interested in the topic of North State fossils. These included a research group with plans to return to Samwel Cave and federal land managers with a heightened interest in fossil resources. The renewed interest in Northern California fossils will spur a resurgence of research and educational opportunities, and the Northern California Natural History Museum is poised to take a leading role in that effort.