Burgess Shale, Yoho National Park

Assembled from 35 blocks · 2 evidence · 19 related

1. Story
2. A Middle Cambrian deposit of about 508 million years old on Fossil Ridge between Wapta Mountain and Mount Field in Yoho National Park, British Columbia, and the most consequential fossil locality ever found for understanding early animals. Charles Doolittle Walcott, then Secretary of the Smithsonian Institution, located the productive beds in 1909 and quarried them over the following years, shipping tens of thousands of specimens to Washington. The animals were buried by sediment flows off the edge of a carbonate platform and preserved as flattened carbon films that retain gills, guts, eyes and limbs. Walcott assigned most of them to existing groups. A re-study begun at Cambridge in 1971 by Harry Whittington with Derek Briggs and Simon Conway Morris dismantled that reading, showing that animals such as Opabinia and Hallucigenia fitted no living phylum comfortably, and the argument over what that means — a lost disparity of body plans, or stem lineages of groups that survive — became one of the defining palaeontological debates of the late twentieth century. The site was inscribed as a World Heritage Site in 1980 and later incorporated into the Canadian Rocky Mountain Parks inscription.
3. Knowledge
4. Konservat-Lagerstätte (exceptional preservation)
5. Burgess Shale, Yoho National Park
6. The Cambrian explosion
7. Connections
8. The Cambrian explosion
9. Konservat-Lagerstätte (exceptional preservation)
10. The Cambrian explosion
11. Walcott locates the Burgess Shale beds
12. The Cambridge re-description of the Burgess fauna begins
13. Molecular clock dating
14. Ediacara Hills, Flinders Ranges
15. Fortune Head GSSP, Newfoundland
16. Konservat-Lagerstätte (exceptional preservation)
17. Burgess Shale, Yoho National Park
18. Anomalocaris
19. Chengjiang fossil site, Yunnan
20. The Great Oxidation Event
21. The end-Ordovician mass extinction
22. Fortune Head GSSP, Newfoundland
23. Burgess Shale, Yoho National Park
24. Chengjiang fossil site, Yunnan
25. Anomalocaris
26. Konservat-Lagerstätte (exceptional preservation)
27. Molecular clock dating
28. The Cambrian explosion
29. Burgess Shale, Yoho National Park
30. Chengjiang fossil site, Yunnan
31. The Cambrian explosion
32. Hou Xianguang finds the Chengjiang fauna
33. Evidence
34. Supports the narrative of Walcott's discovery and classification, the Whittington–Briggs–Conway Morris re-description, and the reassembly of Anomalocaris from three separately named fossils. Gould's own thesis about disparity and contingency is a contested interpretation and is not asserted as fact in this pack. V55 verification basis: this session had no network access to any source — WebFetch was egress-blocked and the WebSearch budget was exhausted — so the cited work was not retrieved and its pagination was not re-checked.
35. Supports the location of the Walcott Quarry on Fossil Ridge in Yoho National Park, the quarrying history and the site's protected status. V55 verification basis: this session had no network access to any source — WebFetch was egress-blocked and the WebSearch budget was exhausted — so the cited work was not retrieved and its pagination was not re-checked. Neither the Parks Canada nor the Royal Ontario Museum documentation was opened, so this record stands on the institutions being the recognised custodians rather than on a retrieved page.