City of Mesa, AZ

Cenozoic Lobby


Lobby photo

Welcome to the Arizona Museum of Natural History! As you enter the museum through the Cenozoic Lobby, animals dating from the Pliocene-Pleistocene Epochs, approximately 3 million years to 10,000 years ago, greet you. These include mammoth, mastodon, American lion, one-toed horse, the armadillo-like Glyptotherium, and four species of fossil turtles.

photo of Mammoth skeleton

Columbian mammoth, Mammuthus columbi. Mammoths entered North America from Eurasia via the Beringia land bridge from Asia to North America between 1.6 and 1.3 million years ago. There are several species of mammoth, but all identified with certainty from Arizona are Columbian mammoths. Columbian mammoths stood up to 13 feet (4 meters) tall at the shoulder and weighed 9.8 tons (10,000 kilograms). They grew tusks up to 16 feet (4.9 meters), the longest in the elephant family!

photo of Mastadon skeleton

American mastodon, Mammut americanum, lived approximately from 3.75 million years ago until 10,000 years ago. This individual, the largest mastodon on display in the world, died between about 17,000 and 13,000 years ago. Mastodons were woodland animals with teeth more adapted to browsing branches than were the grinding teeth of the grass-grazing, more open country mammoths. Adult mastodons stood between 8 and 10 feet (2.5-3 meters) at the shoulder and weighed between 4 and 6 tons (3,500 –5,400 kilograms).

photo of Horse skeleton

The one-toed Hagerman Horse and a limb, skull and tracks of the three-toed horse, Nannippus. Both horses occur at the AzMNH’s 111 Ranch excavations.

photo of lion skeleton

The American lion, Pantheria atrox. The American lion is a little larger than an African lion. The American lion was a powerful predator with large canines and retractable claws. The lion probably killed such large prey as ancient horse and bison and smaller animals such as antelope and deer. The American lion became extinct about 10,000 years ago.

photo of turtle shells

Turtles and tortoises from the 111 Ranch beds in southeastern Arizona, about 2.4 million year old. Left rear: North American giant tortoise, Hesperotestudo. Left front: gopher tortoise, Gopherus. Right front: an accumulation of western box turtles, Terrepene ornata.

Walk under the 8-foot wide megalodon jaws, from Carcharodon megalodon, who lived 23-6 million years ago. This giant shark lived in oceans worldwide, was over 40 feet long and ate meat, preferably whales. Like most sharks, megalodon replaced a lost tooth with the one behind it.



53 N. Macdonald
Mesa, AZ 85201

(One block north of Main Street in downtown Mesa. Take US 60 or 202 to Country Club Drive, go to Main Street, and proceed one-half mile east to Macdonald) - View Map



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