Anodontosaurus

## AnodontosaurusNo Tooth Lizard

### Temporal Range

73 - 67 million years ago, Campanian - Maastrichtian Stage, Late Cretaceous Period

### Episodes

* Forests (Segment 5)
* How Did Ankylosaurs Use Their Tail? (Cameo, Fossil and Diagram only)

## Characteristics

### Diet

Herbivore

Has a uniquely-shaped tail club that is wide and pointed on both sides

***Anodontosaurus*** (No Tooth Lizard, a misconception made due to compression damage removing the holotype's teeth, making it appear toothless), simply referred to as "a two-tonne ankylosaur" on the show, is a genus of ankylosaurid dinosaur that lived in the Horseshoe Canyon Formation in southern Alberta, Canada, 73 - 67 million years ago, during the Maastrichtian stage of the Late Cretaceous Period.

## Paleobiology

As an ankylosaurid, *Anodontosaurus* is a large, heavily-armored animal, around 4 - 5 meters (13 -16 feet) in length and 2 metric tons (2.2 short tons) in mass. Its tail club is unique in shape compared to those of other ankylosaurids, being wide and pointed on both sides. Prehistoric Planet depicts *Anodontosaurus* with an emerald-colored body and a creamy yellow underside. It also has black, shiny nictitating membranes, perhaps to help protect the eyes from the heat of the forest fires that constantly occur in the area.

## Paleoecology

### Paleoenvironment

*Main: Horseshoe Canyon Formation*

Main: Horseshoe Canyon Formation

***“ In the forests of North America, there is an additional annual hazard for forest-dwellers. Fire, started by a strike of lightning. As it spreads, temperatures rise to over 2000 degrees Fahrenheit. The flames rise several hundred feet into the air. ”***

― **David Attenborough**, *Forests*
*Anodontosaurus* lived 73 - 67 million years ago in the Horseshoe Canyon Formation in southern Alberta, Canada, which by that time was an area of floodplains, estuaries, and coal swamps. The area likely also had its share of forests that thrives in such environments and, as the show depicts, is vulnerable to the threat of fire started by a single strike of lightning.

### Feeding Preferences and Adaptations

***“ A two-tonne ankylosaur. It also finds something worth eating after a fire. Charcoal. It will bind with many of the plant toxins in its stomach, and neutralize them. ”***

― **David Attenborough**, *Forests*
In its brief appearance, *Anodontosaurus* is shown to be a solitary animal. It also appears to be one of the first animals to return to the forest just hours after it burned, perhaps feeling more secure due to its armored hide and fearsome weaponry. Much like the *Triceratops* which appeared earlier in the same episode, *Anodontosaurus* seems to be smart enough to recognize the poison-neutralizing properties of some substances, except rather than feed on certain mineral-infused clay to bind away many of the toxic plants within its stomach, *Anodontosaurus* instead consumes charcoal, which has similarly-helpful protective effects.

## Appearances

### Forests

In the fifth segment of the episode, in the ruins of a forest ravaged by fire just hours before, animals begin to return. Beetles arrive to lay their eggs (for their larvae would feast on the near-limitless supply of dead wood). An *Atrociraptor*, taking advantage of the situation, feeds on one of the beetles, and picks up a smoking twig to rid itself of parasites. Sensing a large animal coming close, the *Atrociraptor* flees the scene as a two-tonne *Anodontosaurus* arrives to feed on a newly-burned tree stump to help aid digestion by purifying its stomach, the toxins of the many plants it ate neutralized by the charcoal it consumes.

### Prehistoric Planet: Uncovered - How Did Ankylosaurs Use Their Tail?

***“ When they were first discovered, they were interpreted as a weapon of some kind. This one belonged to a kind of ankylosaur known as 'anodontosaur'. But what makes us think that this was ever wielded like a club? Comparing ankylosaurs with animals alive today suggests that it was. ”***

― **David Attenborough**, *Forests*
During this Uncovered segment, which was dedicated to discussing the purpose of ankylosaur tail clubs, the uniquely-shaped tail club of *Anodontosaurus* is briefly shown in a diagram and as a fossil in the following scene.

## References

1. ↑ 1.0 1.1 1.2 *The Princeton Field Guide to Dinosaurs*
2. ↑ 2.0 2.1 2.2 Unusual cranial and postcranial anatomy in the archetypal ankylosaur *Ankylosaurus magniventris*
3. ↑ 3.0 3.1 As stated in Forests.
4. ↑ Naish, Darren (@TetZoo) (June 18, 2022) on Twitter, confirming the identity of the "two-tonne ankylosaur"