Pikaia

paleontology

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Last updated

July 1, 2026

Quick Summary

Pikaia gracilens is the oldest known fossil chordate, dating back approximately 505 million years to the Cambrian Period. This primitive creature was a cephalochordate, a group that also includes modern-day lancelets. While the exact appearance of Pikaia is debated, it is understood to have possessed key chordate features such as a notochord, a dorsal nerve cord, and gill slits. Its discovery provides crucial insight into the early evolution of chordates, the phylum that eventually gave rise to vertebrates.1

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cephalochordate
Evolution and paleontology
A good possibility is Pikaia, a fossil discovered in the Burgess Shale (Middle Cambrian, about 530 million years old). Pikaia has myotomes and what looks like a notochord, indicating that it is a chordate, but only its shape suggests that it is a lancelet rather than a fish.
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A good possibility is Pikaia, a fossil discovered in the Burgess Shale (Middle Cambrian, about 530 million years old). Pikaia has myotomes and what looks like a notochord, indicating that it is a chordate, but only its shape suggests that it is a lancelet rather than a fish.
Read More