Ankylosauria

Lore & Background

The origin of ankylosaurs is poorly understood, with only a few Middle Jurassic specimens known. They are closely related to stegosaurs within Eurypoda, united by the presence of skin osteoderms and similar skull and palate structures. Ankylosaurs were definitely present in Africa by the Bathonian age, as evidenced by Spicomellus in Morocco. A possible Early Jurassic origin has been suggested but remains uncertain. Ankylosaurs evolved toward increased armor and consolidation of the carapace, suggesting the ancestor had separate non-fused osteoderms.

Reader's Guide

Ankylosauria represents a major group of armored dinosaurs that persisted for over 80 million years, from the Middle Jurassic to the end of the Cretaceous. Their significance lies in their extreme defensive adaptations: extensive bony armor covering the head, back, and sides, often fused into a solid carapace. This armor included scutes, nodules, and sometimes large spines, with neck rings of fused or adjoining scutes. Ankylosaurs were low-browsing herbivores, typically feeding at or below one meter in height, with small triangular teeth, long flexible tongues, and a secondary palate allowing breathing while chewing. Their large gut suggests fermentation digestion of ferns, cycads, and angiosperms. The group's classification has been debated, with recent studies proposing alternative family arrangements beyond the traditional Nodosauridae-Ankylosauridae split.

Did You Know?

• The name Ankylosauria can mean 'rigid lizard' or 'curved lizard' due to an early misinterpretation of their back shape.
• Ankylosaurs had a secondary palate that allowed them to breathe while chewing, unlike crocodiles.