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In 1936, a remarkable discovery was made by a teenager from California’s Central Valley.
Allan Bennison, a student at Gustine High School, unearthed the fossilized remains of a hadrosaurus—commonly known as a duck-billed dinosaur—which thrived in North America during the Late Cretaceous Period. This finding, reported by The Fresno Bee in 2013, marked the first scientifically documented dinosaur fossil discovery in the state.
Not long after, Bennison stumbled upon the preserved skull and spine of a mosasaur in the nearby foothills, leading to the creature being named Plotosourus bennisoni in honor of his contributions. Michael George, the lead paleontologist at the Fossil Discovery Center of Madera County in Chowchilla, noted, “Most paleontological finds are made by amateur fossil enthusiasts and everyday citizens. Their enthusiasm helps us palaeontologists explore and work on more fossils each day.”
The Central Valley is rich in fossil discoveries, with significant finds contributing to the understanding of California’s prehistoric ecosystem, including the state’s official dinosaur.
Why is the Central Valley a prime site for dinosaur fossils?
While many perceive the Central Valley as dominated by agriculture and flat terrain, George asserts that it is actually a treasure trove of prehistoric artifacts. “Most of California was submerged during the Mesozoic Era, which lasted around 252 to 66 million years ago,” he explained. “This is the reason for the prevalence of prehistoric marine species, including mosasaurs, ammonites, and even megalodon teeth found throughout the state.”
Additionally, George noted the fossils of Ice Age megafauna, such as mammoths, dire wolves, saber-toothed cats, camels, and ground sloths, can be found extensively across the Central Valley. He acknowledged that although California is not the ideal environment for dinosaur fossil preservation, there have nonetheless been discoveries, primarily of hadrosaurs from the Late Cretaceous period.
These herbivorous dinosaurs thrived in what was once a coastal plain, with their remains predominantly discovered in areas that were previously underwater, such as parts of the San Diego Formation. Other notable fossils include Aletopelta coombsi, an ankylosaur species identified in Southern California, which was unearthed near Carlsbad in 1987, according to Smithsonian magazine.
California’s state dinosaur discovered in Fresno County
Among the most notable fossil finds in the Central Valley is Augustynolophus morrisi, a hadrosaur that roamed California roughly 66 million years ago. This duck-billed dinosaur, measuring around 26 feet in length and weighing about 3 tons, has only two known fossil specimens. Both were excavated from rock layers previously located at the bottom of the ancient Pacific Ocean: the first near Fresno County in 1939 and the second in San Benito County in 1941, as reported by The Fresno Bee in 2017. Today, these specimens are housed at the Natural History Museum of Los Angeles County.
The nomenclature of A. morrisi pays tribute to philanthropist Gretchen Augustyn and paleontologist William J. Morris. George mentions that while it remains speculative how the dinosaur reached the Central Valley, its discovery in the Moreno Formation, more commonly known for marine reptiles, suggests that it may have washed out to sea after dying near the coastline.
In 2017, California solidified A. morrisi’s significance by officially naming it the state dinosaur through legislation signed by then-Governor Jerry Brown. State Assemblyman Richard Bloom highlighted the pride of Fresno County residents in being linked to this unique prehistoric creature.
Where to explore dinosaur-themed attractions in the Central Valley?
The Central Valley boasts several dinosaur-related attractions, catering to both sporadic events and permanent exhibits. In January, the Big Fresno Fair featured a traveling Dinosaur Adventure, characterized as a unique exhibit showcasing life-sized, lifelike moving dinosaurs.
Events also occurred at Fresno’s Chaffee Zoo, which hosted an overnight dinosaur-themed adventure that included fossil searches. Many museums in the region display fossils, including the Buena Vista Museum of Natural History in Bakersfield, while the Fresno Discovery Center features large dinosaur sculptures and interactive science exhibits, allowing children to dig for fossils in a simulated environment.
The Fossil Discovery Center of Madera County invites visitors to learn about Pleistocene epoch inhabitants of the Central Valley. Located adjacent to the Fairmead landfill—home to one of North America’s largest middle-Pleistocene fossil excavations—the center showcases fossil remains of a variety of ancient animals, such as camels, horses, giant sloths, and saber-toothed cats. In addition, it provides full-scale replicas of prehistoric creatures, including a Columbian mammoth and a towering short-faced bear.
George emphasized the uniqueness of the Fossil Discovery Center, stating, “Most people would have to visit the La Brea Tar Pits in Los Angeles to see some of these ancient species, making this facility a special opportunity for residents.” He added that the center’s goal is to inspire the next generation of paleontologists.
Reflecting on his own childhood, George noted that many young students have since pursued careers in paleontology after being inspired at a young age. He also acknowledged the widespread fascination with prehistoric life among adults, often noting that he frequently sees more adults captivated by the fossils than children.
How can one legally search for fossils in California?
Fossils are classified as a non-renewable resource, necessitating a special permit for legal fossil hunting, as the removal of fossils from federal or state land is prohibited without authorization. However, if a fossil is discovered on private property, it technically belongs to the finder.
The Ernst Quarries in Bakersfield provides opportunities for aspiring paleontologists to dig in designated “bonebeds,” primarily yielding marine fossils like shark teeth and clams. Visitors can pay between $15 and $40 to access the site, which is adjacent to Sharktooth Hill—one of the world’s most significant marine fossil locations, as noted by the Buena Vista Museum of Natural History.
The quarries equip visitors with all necessary tools for fossil excavation, and participants can retain their finds, excluding those deemed scientifically significant, such as skulls or articulated skeletons, which are retained for museum exhibits.
Source
phys.org