Which dinosaurs dominated prehistoric Arizona? Valley 101 finds out

Kaely Monahan, Arizona Republic
·2 min read
A 20-foot long, life-size bronze Dilophosaurus, created for the Mesa Southwest Museum by artist Michael Trcic, of Sedona, is a native species to Arizona.
A 20-foot long, life-size bronze Dilophosaurus, created for the Mesa Southwest Museum by artist Michael Trcic, of Sedona, is a native species to Arizona.

Prehistoric Arizona was a wild place. Volcanoes, earthquakes and several incursions by the ocean remade the land over the course of millions of years. The reign of the dinosaurs was punctuated by these geological changes.

Starting in the Triassic Period, almost 252 million years ago, parts of our state burst with verdant foliage. The Petrified Forest in northern Arizona was alive during this time. It was in this period that the first dinosaurs evolved.

Fast forward roughly 50 million years to the Jurassic Period, much of what would become Arizona dried out. Some areas were even covered in sand dunes. Volcanoes loomed over various parts of the state. You can see their remnants in places like the Huachuca and Santa Rita Mountains.

Besides the active volcanoes, there were numerous earthquakes. Enormous tectonic forces moved the continents throughout the Mesozoic era. In Arizona, land could just as easily be pushed up as pulled apart. In fact, some parts of the state where the elevation changes sharply are remnants of where the land was rent apart by these tectonic forces.

Despite the upheaval, dinosaurs of all kinds stomped through our region. From the popularized Dilophosaurus – which did not have a frill – to the enormous, long-necked Sonorasaurus, Arizona's dinosaurs were spectacular. At least as far as researchers can tell.

We know very little about Arizona's dinosaur age. It was nearly wiped clean from the paleontological record. But why?

In this episode of Valley 101, we dig up the answers to what kinds of dinosaurs lived here and why there are so few fossil records in our state.

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The Arizona Museum of Natural History in Mesa is home to several animatronic dinosaurs that roar.
The Arizona Museum of Natural History in Mesa is home to several animatronic dinosaurs that roar.

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An artist's depiction of the oreodont "Merychyus," which lived some 40 million years ago during the Miocene period. Producer Kaely Monahan and Paleontologist Gavin McCullough found fossils of this animal. Drawn by Gavin McCullough, a paleontologist with the Arizona Museum of Natural History.
An artist's depiction of the oreodont "Merychyus," which lived some 40 million years ago during the Miocene period. Producer Kaely Monahan and Paleontologist Gavin McCullough found fossils of this animal. Drawn by Gavin McCullough, a paleontologist with the Arizona Museum of Natural History.

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"Jurassic World: Dominion" comes to theaters June 10, 2022.

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This article originally appeared on Arizona Republic: Which dinosaurs dominated prehistoric Arizona? Valley 101 finds out