Ankylosauria
Armored herbivorous dinosaurs with fused bony shields.
Ankylosauria is a group of herbivorous dinosaurs within the clade Ornithischia, known for their extensive armor of bony osteoderms similar to turtles. They were bulky quadrupeds with short, powerful limbs, first appearing in North Africa during the Middle Jurassic and persisting until the end of the Late Cretaceous. The group includes the majority of armored dinosaurs and is divided into two main families, Nodosauridae and Ankylosauridae, primarily from the Northern Hemisphere, as well as the more basal Parankylosauria from southern Gondwana.
- Temporal range
- Middle Jurassic to end of Late Cretaceous
- Earliest known location
- North Africa (Morocco)
- Classification
- Suborder or infraorder within Thyreophora
- Key subgroups
- Nodosauridae, Ankylosauridae, Parankylosauria
- Distinctive feature
- Armor of fused bony osteoderms covering back and sides
Lore & Background
The name Ankylosauria derives from Greek ἀγκύλος (ankylos) meaning 'curved' or 'bent', with the anatomical sense 'hard' or 'fused', and σαῦρος (sauros) meaning 'lizard'. The name thus carries possible meanings of 'rigid lizard' or 'curved lizard'.
Reader's Guide
Ankylosauria represents a major evolutionary lineage within Thyreophora, alongside Stegosauria, and is significant for its extensive dermal armor, which evolved from separate non-fused osteoderms into consolidated carapaces covering the skull, back, and sides. Their low-slung build, small triangular teeth, large hyoid bones indicating long flexible tongues, and expanded gut region suggest a diet of low-growing vegetation such as ferns, cycads, and angiosperms, processed through fermentation. The group's classification has been debated, with some studies proposing a redefinition to exclude early forms like Scelidosaurus, while others retain traditional boundaries. Ankylosaurs also provide rare evidence of dinosaur vocalization: a fossilized larynx from Pinacosaurus grangeri suggests bird-like sounds produced low in the trachea.
Did You Know?
- The earliest known ankylosaur, Spicomellus, comes from the Bathonian age of Morocco.
- Possible neonate-sized ankylosaur fossils have been documented in scientific literature.
- A fossilized larynx from Pinacosaurus grangeri suggests ankylosaur vocalizations may have been bird-like.
Frequently Asked Questions
What exactly is Ankylosauria?
Ankylosauria is a suborder (or infraorder) of herbivorous dinosaurs nested within Thyreophora and the broader Ornithischia clade. These bulky, four-legged dinosaurs are best recognized for their heavy body armor made of fused bony osteoderms.
What is the most distinctive feature of Ankylosauria?
Their defining trait is the extensive plating of fused bony osteoderms that covered their backs and flanks, giving them a turtle-like armored appearance. This shield-like protection set them apart from most other dinosaur groups.
When and where did Ankylosauria first appear?
The earliest known ankylosaurians date to the Middle Jurassic and were found in what is now Morocco in North Africa. The group persisted all the way through to the very end of the Late Cretaceous.
What are the main families within Ankylosauria?
The group splits into two principal families, Nodosauridae and Ankylosauridae, both predominantly found in Northern Hemisphere deposits. A more basal lineage called Parankylosauria is also recognized from southern Gondwana.
Why do fans and paleontologists care about Ankylosauria?
They represent the majority of all known armored dinosaurs, making them central to understanding how heavy armor evolved in herbivorous reptiles. Their long survival from the Middle Jurassic to the end of the Cretaceous also makes them a key group for tracking evolutionary trends across Mesozoic ecosystems.
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