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Tatankacephalus, Early CretaceousCloverly Formation, Montana · named 2009
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Tatankacephalus

"bison head"

Lived
113 to 101 million years ago, Early Cretaceous
Diet
Herbivore
Group
Ankylosaurs, Nodosauridae
Found in
United States
Named by
Parsons and Parsons 2009

Where its fossils were found

The evidence

Today

1 find

105 million years ago

Map: C. R. Scotese, PALEOMAP

Habitat

It probably lived on river floodplains in what is now Montana. The Cloverly Formation also preserves Sauropelta, Deinonychus and Tenontosaurus.

Field notes

About Tatankacephalus

What it was like

Tatankacephalus was an armored plant eater known from a partial skull. Some ribs and armor found with it may belong to the same animal. It has been placed among both ankylosaurids and nodosaurs, and its exact position remains uncertain.

Its world

It lived in the Early Cretaceous in what is now Montana, in the United States. Its bones come from the Cloverly Formation, where it shared the land with the nodosaur Sauropelta, the sickle-clawed Deinonychus and the plant eater Tenontosaurus.

How it was found

Parsons and Parsons named Tatankacephalus in 2009, from a single find.

Field gallery

More views of Tatankacephalus

Scenes reconstructed from the available fossil evidence.

Tatankacephalus in its habitat, photo 1

1 of 2

Lived alongside

Found in the same rock formations

A rock formation can hold fossils laid down millions of years apart, so not every animal here met Tatankacephalus.

The evidence

The science behind Tatankacephalus

Which parts of the picture come from its own bones, and which come from its relatives.

From its own fossils

  • Pieces of one skull preserve a smooth dome on the roof, a curved ridge across the back of the head and a round eye socket.
  • Bony bosses stick out at the sides of the head: a diamond-shaped bone above the eye, a pyramid-shaped boss behind it and another low on the cheek. The tip of the snout carried teeth.
  • Two pieces of bony armor and some ribs found with the skull may come from the same animal.

Borrowed from relatives

  • The missing lower jaw, neck and shoulders are restored by comparison with Europelta, a nodosaur from Spain.
  • The full length of the skull was estimated from the proportions of Gargoyleosaurus.

Still unknown

  • How some pieces of the skull roof fitted together, and the full shape of its snout and lower jaw.
  • The arrangement of armor across its body.
  • Its exact place among armored dinosaurs. It was first described as an early ankylosaurid, a later study placed it among the nodosaurs, and a recent one found it either unresolved or grouped with Sauropelta, depending on the analysis.

Discovery timeline

  1. 2009Named itParsons & Parsons
  2. 2011Family treeThompson et al.
  3. 2013Same rocksOreska, Carrano & Dzikiewicz
  4. 2013Full descriptionKirkland et al.

Key papers

The research behind what we know of Tatankacephalus

Close relatives

Other members of Nodosauridae

Sources: Wikidata