The University of Glasgow uses cookies for analytics. Find out more about our Privacy policy.
Necessary cookies enable core functionality. The website cannot function properly without these cookies, and can only be disabled by changing your browser preferences.
Analytical cookies help us improve our website. We use Google Analytics. All data is anonymised.
Clarity helps us to understand our users’ behaviour by visually representing their clicks, taps and scrolling. All data is anonymised.
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Agnatha
Name derivation: “without jaws”
Order Count: 2
Family Count: 4
Genus Count: 16
Species Count: 129
Earliest Fossil Record: Early Cambrian 538 – 521 mya
Habitat: Marine, Freshwater
Size Range: 13 cm to 1.3 m
Notes: Based on Catalogue of Life as of March 2025