Question

How did the fossils of the Burgess Shale likely form?

1) The animals fell to the bottom of a deep lake and over thousands of years turned to rock
2) The animals dropped into anoxic ocean depths and were covered by fine sediment
3) The animals were rapidly covered by ash falling from a volcano
4) Shallow seas disappeared, exposing mud sediments to the air

Answer 1

The fossils of the Burgess Shale likely formed through bioturbation, with organisms burrowing and moving through sediment on the ocean floor. These burrows were preserved as trace fossils when the sediment hardened into rock. The Burgess Shale contains soft-bodied imprints of various life forms and is known for its fossils from the Cambrian explosion.

Step-by-step explanation:

The fossils of the Burgess Shale likely formed through a process called bioturbation. Organisms burrowed and moved through sediment on the ocean floor, and when the sediment hardened into rock, their burrows were preserved. These preserved burrows are known as trace fossils.

The Burgess Shale is famous for its 508 Ma fossils that mark the Cambrian explosion, and it contains soft-bodied imprints of various life forms. The fossils were buried and covered by layers of silt and sand over time.