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Ankylosaurus osteoderm

SKU

DK21

In stock

$3,250.00

Overview

A LARGE, Top Quality Ankylosaurus osteoderm (bony armor plate) with a center keel from the late Cretaceous of northern North America. An August Fossil of the Month. Ankylosaurus magniventris was the largest Ankylosaur which grew to 30 feet and 17000 pounds, and a body covered with this bony armor. A complete body osteoderm plate with a central keel from an adult Ankylosaurus. The bone quality is exceptional with excellent color and patina. Plus natural blood grooves cover the surface of this scute. There is one crack. No restoration. Legally collected on private land in the Hell Creek Fm., Walworth Co., So. Dakota. Authenticity guaranteed. An exceptional collector's quality Ankylosaur osteoderm with a center keel! Best quality.

DK21 SIZE: 5-7/8" x 4-3/4" ; Keel height: 1-1/2"

Note - Adding 10 new Ankylosaur - Nodosaur fossils in August 2026. Link to Ankylosaur fossils catalog.

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Details

Ankylosaurs and the Nodosaurs, their cousins, are the familiar armored dinosaurs from the late Cretaceous period. They were covered with osteoderms or boney plates of protective armor, and the Ankylosaurs had a clubbed tail for added defense. The Ankylosaurs and the Nodosaurs were large. Ankylosaurus, the largest Ankylosaur, reached lengths up to 30 feet and weight to 17000 lbs. Edmontonia, a Nodosaur, reached lengths of 22 feet and weighed up to 7000 lbs. These dinosaurs were built close to the ground, wide barrel-chested, and quadrupedal. You can see them referred as the “tanks” of the dinosaur world, and would be quite challenging for a Tyrannosaur or raptor to attack; especially, the Ankylosaurs with their club tails. Many Tyrannosaurs including Tyrannosaurus rex have been found with broken and healed leg fractures. Those dinosaurs may have survived an encounter with an Ankylosaur.

Ankylosaurs and the Nodosaurs were herbivores. They had good sized teeth for cutting or nipping low lying vegetation. Today, we find their fossilized teeth, osteoderms (armor plates), and bones. We have a great assortment of Ankylosaurus fossils for sale. Note – Ankylosaurus was a rare species composing of only 1% of the dinosaurs species found in the Hell Creek Formation.

Species include the following –

Ankylosaurus magniventris – the largest Ankylosaur, Hell Creek Formation; 67-66 mya

Denversaurus schlessmani - the Hell Creek Fm. Nodosaur ; 67-66 mya

Euplocephalus tutus – an Ankylosaur, Judith River / Two Medicine / Horseshoe Canyon Fm.; 76-75 mya

Edmontonia rugosidens – a Nodosaur, Judith River / Two Medicine / Horseshoe Canyon Fm.; 77-69 mya

Zuul crurivastator - an Ankylosaur, Judith River Fm. - Montana; 80 -75 mya