BOVINA, Miss. -- While playing near their backyard in a Mississippi town, three boys dug up the jawbone of one of the largest animals of the Ice Age, Fox News reports.
"I thought it was a log and I tried to pick it up and it was really heavy and I saw teeth on it," 12-year-old Caid Sellers said.
At first, Caid, his 10-year-old brother Shawn and their cousin Michael Mahalitc thought it was a dinosaur bone but when they called a local paleontologist they found out it was from a mastodon -- an ancient elephant-like animal.
"We've gotten a lot of petrified wood from the area. Civil War relics from the area and I -- that's what I thought it was. This is our first set of teeth we've found," Caid and Shawn’s mother Lynett Welch said.
Mastodons lived in parts of North and Central America during the Ice Age and went extinct about 11,000 years ago. What the boys found was a mostly-intact fossil that weighs around 50 pounds.
Paleontologist George Phillips says it's rare.
"We find pieces of Ice Age creatures all the time. You might find a fragment of a mastodon tooth or perhaps you know part of a bone. But they found a really intact half lower jaw with two teeth," Phillips said.
The giant animals are often confused with mammoths and elephants. One thing that differentiates mastodons and mammoths are their teeth. The mastodon tooth has deep valleys and ridges while the mammoth tooth is shaped like an accordion.
The family plans to figure out the best way possible to preserve the ancient jawbone and the boys say they will keep on digging.