Name: Sonorasaurus thompsoni

“Thompson’s Sonora Lizard”

Classification: Sonorasaurus is a Brachiasaurid dinosaur, a smaller relative of the more well-known Brachiosaurus

Fun Fact: Sonorasaurus is the oldest known Brachiasaurid dinosaur from the middle Cretaceous.

Named the Arizona State Dinosaur on April 10, 2018

Time Period: middle and late Cretaceous Period, 105 to 93 million years ago. The Cretaceous was the last era of the non-avian dinosaurs.

Length: about 15 meters (49 feet)

Height: 8.2 meters (27 feet)

Weight: about 42 tons (84,000 pounds)

Diet: Vegetation, probably trees

Habitat: wetlands near the ocean, it's range definitely included Pinal County.

Fossils Found: Only one location in the Turney Ranch Geological Formation, Whetstone Mountains, Cochise County, southeastern Arizona

When Found: The first Sonorasaurus fossils were discovered in November 1994 in the southeastern Arizona and was excavated by paleontologists at the Arizona-Sonora Desert Museum in Tucson.

Formally described: 1998 by Ronald Ratkevich.

Fun Fact: He originally wanted to name the dinosaur “Chihuahuasaurus” but he decided that it would be silly name for a 49-foot-long animal, so he named it after the larger Sonoran Desert that the Chihuahuan Desert is part of.

Fun Fact: The animal had been killed or scavenged by a large predator, perhaps Acrocanthosaurus, a relative of Allosaurus. An Acrocanthosaurus tooth was found near the skeleton of the Sonorasaurus.

Eastern Arizona was repeatedly inundated by the sea during the Cretaceous and the remains of Sonorasaurus were found in sandstone, probably deposited on or at the edge of the ocean.

 Replica of the Sonorasaurus fossil site. Arizona-Sonora Desert Museum. Ray Grant Photo.