Burgess Shale Geoscience Foundation - The trilobite specimen on the left is a molt while the one on the right is a full specimen. Trilobites needed to shed their exoskeleton to grow
![Some of Earth's first animals—including a mysterious, alien-looking spaceship—are spilling out of Canadian rocks - The Burgess Shale Geoscience Foundation Some of Earth's first animals—including a mysterious, alien-looking spaceship—are spilling out of Canadian rocks - The Burgess Shale Geoscience Foundation](https://www.burgess-shale.bc.ca/wp-content/uploads/2020/10/ma_1123_Cambrian_mothership_700px.jpg)
Some of Earth's first animals—including a mysterious, alien-looking spaceship—are spilling out of Canadian rocks - The Burgess Shale Geoscience Foundation
![Burgess Shale Mt. Stephen Trilobite Beds Field Course / Field Trip - Calgary to Field BC Yoho National Park Burgess Shale Mt. Stephen Trilobite Beds Field Course / Field Trip - Calgary to Field BC Yoho National Park](https://www.geohistory.ca/i/burgess-shale-walcott-quarry.jpg)