Exquisitely Preserved Ankylosaur Dinosaur Skull

Name: Pinacosaurus grangeri

Phylum Chordata, Class Sauropsida, Superorder Dinosauria, Order Ornithischia, Suborder Thyreophora, Infraorder Ankylosauria, Family Ankylosauridae, Subfamily Ankylosaurinae

Geological Time: Upper Cretaceous Campanian Stage (~83 m.y.a.)

Size: The width of the skull is 12 1/2", depth is 6" and the length is 12 1/2" including the vertebrae (10 1/2" without vertebrae).

Fossil Site: Bayan Mandahu (= Djadochta) Formation, Bayn Dzak, Gobi Desert of Mongolia

Ankylosaur Dinosaur SkullThis is the well-preserved skull of an armored dinosaur known as Pinacosaurus grangeri from the famous Bayan Mandahu location in the Gobi that was initially discovered by Charles Gilmore in 1933. Gilmore was a member of the famous Central Asiatic Expeditions to the Gobi led by Roy Chapman Andrews in the 1920’s. Bayn Dzak is the most famous of all locations, and was termed the Flaming Cliffs by Andrews. Gilmore originally placed the badly crushed skull and scattered other material he found in the Nodosauridae, but Pinacosaurus was subsequently found to be a member of the Ankylosauridae. At 5 meters in overall length, Pinacosaurus was a medium-sized ankylosaur which shared in common with Saichania a most unusual trait: the possession of thin curved bones similar to the respiratory turbinal bones of mammals. They are the only reptiles positively known to possess these structures that were thought to warm, filter, and moisten incoming air.

While most ankylosaurs are thought to have been solitary animals, a discovery of several juvenile specimens announced by a joint Chinese-Canadian expedition to the Gobi in 1988 suggested that the sheep-sized babies might have been smothered during a sandstorm. While several specimens are known that range in size from adult to juvenile, very little well-preserved adult cranial material is known, making this a most exceptional specimen of undoubted museum quality.

Although skeletal bones of Pinacosaurus are relatively common at the site, this is one of only two known adult skulls of diagnostic quality, and is a most majestic and valuable specimen. The Djadokhta Formation of Mongolia from which the specimen comes yielded the first undoubted dinosaur eggs, Protoceratops, Velociraptor and many other theropods. In addition, many examples of turtles, crocodiles, lizards and mammals have been discovered.

The specimen has no restoration and is essentially unprepared. The pictures below provide many perspectives (or lighting) of this unique Cretaceous dinosaur fossil.

click fossil pictures to enlarge

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