Anomalocaris fossil map
Where fossils of Anomalocaris have been found, shown on the Earth as it looked about 525 million years ago and on today’s map.
Dots are fossil collections recorded in the Paleobiology Database. The “then” view moves today’s fossil sites back to their positions 525 million years ago (the time slice nearest the median age of the fossils) using the Merdith et al. (2021) plate model; positions are approximate. Open on the timeline map →
| Group | Ediacaran & Cambrian life |
|---|---|
| Lived | 521–497 million years ago (Stage 3 to Guzhangian) |
| Periods | Cambrian |
| Family | Anomalocarididae |
| Fossil records | 34 occurrences at 24 locations (PBDB) |
| Found in | United States, Canada, China, Australia |
| Rock formations | Kinzers, Burgess Shale, Pioche Shale, Yuanshan, Parker Slate, Pioche |
About Anomalocaris
Anomalocaris (from Ancient Greek ανώμαλος, meaning "anomalous", and καρίς, meaning "shrimp", with the intended meaning "unlike other shrimp") is an extinct genus of radiodont, an order of early-diverging stem-group marine arthropods. It is best known from the type species A. canadensis, found in the Stephen Formation (particularly the Burgess Shale) of British Columbia, Canada. The other named species A. daleyae is known from the somewhat older Emu Bay Shale of Australia. Other unnamed Anomalocaris species are known from China and the United States.
Like other radiodonts, Anomalocaris had swimming flaps running along its body, large compound eyes densely packed with lenses, and a single pair of segmented, frontal appendages, which in Anomalocaris were used to grasp prey. Estimated to reach 34.2–37.8 cm (13.5–14.9 in) long excluding the frontal appendages and tail fan, Anomalocaris is one of the largest animals of the Cambrian, and thought to be one of the earliest examples of an apex predator, though others have been found in older Cambrian lagerstätten deposits.
Text in “About” is quoted from the Wikipedia article Anomalocaris (revision 1379615198), licensed under CC BY-SA 4.0; introduction excerpted verbatim, formatting removed. Ages, family, authority and fossil records: Paleobiology Database, accessed 22 October 2026. Ages are those of the rock layers the fossils were found in.
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