One of the terms that you might come across when reading about different types of dinosaur dentition (their teeth) is the term foliodont. Foliodont is from the Latin and it translates as “leaf tooth”, the term is used to describe teeth that have a leaf-shaped crown. For example, armoured dinosaurs (Thyreophora), have leaf-shaped teeth.

The diagram below, shows typical stegosaur teeth (A and B) and typical ankylosaur teeth (C, D) from Maidment et al (2008).

Examples of Thyreophoran teeth (stegosaur and ankylosaur)
Examples of thyreophoran teeth. Teeth of stegosaurs (A, B) and ankylosaurs (C, D) showing typical foliodont characteristics. The leaf-shaped teeth come from (A) Paranthodon, an Early Cretaceous stegosaur from South Africa, whilst B is from Stegosaurus armatus from the Morrison Formation of the western USA. The ankylosaur tooth (C) is from Sauropelta edwardsorum from the Cloverly Formation of the USA and (D) is from Edmontonia rugosidens from the Upper Cretaceous deposits of the Horseshoe Canyon Formation (Canada). Scale bar for (A, B) equals 0.5 cm, whilst scale bar for (C, D) equal 1 cm. Picture credit: Maidment et al.
Small stegosaur tooth from the dentary.
Small, relatively unworn tooth of an indeterminate stegosaur from the Teete locality in (A) occlusal, (B) labial and (C) lingual views. These teeth in labial and lingual view can be described as foliodont. Picture credit: Skutschas et al

Beware of Wear

Unfortunately, perfectly preserved and entire teeth are exceptionally rare. Worn, broken teeth are much more common, either as a result of the shedding of teeth when the thyreophoran was alive or as a result of distortion during the fossilisation process (taphonomy). This can lead to difficulties when trying to assign isolated teeth fossils to a particular family or genus.

Whilst general characteristics of tooth morphology can be discerned from a fragmentary, partial specimen and some idea of diet can be surmised, identifying the taxon represented is extremely difficult.

For example, worn teeth discovered in the Arctic circle indicate that stegosaurs were present in Siberia during the Early Cretaceous, at what was a high palaeolatitude, but in the absence of more substantial fossil material little more about the dinosaurs present can be discerned.

To read our blog post about Arctic stegosaurs: Studying Stegosaurs that Lived in the Arctic Circle.