This week in PNAS, the ANOM Lab (Daley, Antcliffe, Drage & Pates) published a Perspective that examines multiple sources of fossil data – including exceptionally preserved BST-type fossils, shelly fossils, microfosssils and trace fossil – to describe the timing of the origin and evolution of euarthropods. By comparing the modes of preservation between the Cambrian and Precambrian, we concluded that there is no evidence for euarthropods in the Precambrian. Using this comprehensive approach, we suggest that the first appearance of euarthropods was between 537 and 550 million years ago. There was no deep Precambrian root to the origin of euarthropods, and instead this evolution played out during the first 30 to 40 million years of the Cambrian. Read about it here:
Reconstruction of the Cambrian predator and stem-lineage euarthropod Anomalocaris canadensis, based on fossils from the Burgess Shale, Canada. Reconstruction by Natalia Patkiewicz.
Reconstruction of the Cambrian predator and stem-lineage euarthropod Anomalocaris canadensis, based on fossils from the Burgess Shale, Canada. Reconstruction by Natalia Patkiewicz.
The famous fossil locality The Burgess Shale in the Canadian Rocky Mountains, where abundant exceptionally preserved soft-bodied fossils from the Cambrian (508 million years old) are found. Image credit A. Daley.
The fossil that started it all! Appendages of Anomalocaris canadensis like this one were first described from Mouth Stephen in 1892, a few years before the Burgess Shale was discovered!
Exceptionally preserved soft-bodied fossil of the Cambrian predator and stem-lineage euarthropod Anomalocaris canadensis from the Burgess Shale. Image credit A. Daley.
Exceptionally preserved soft-bodied fossil of the Cambrian predator and stem-lineage euarthropod Anomalocaris canadensis from the Burgess Shale. Image credit A. Daley.
