Trilobites are typically found in which deposits?

Trilobites are typically found in which deposits?

• A. Cretaceous terrestrial deposits
• B. Cambrian marine deposits
• C. Permian desert deposits
• D. Devonian reef deposits

Answer: (B)

Trilobites are strong indicators of early Paleozoic marine environments, with their fossils most abundant in Cambrian rocks. They were abundant in shallow seas during the Cambrian, and their hard, mineralized exoskeletons fossilize well in marine sediment, so Cambrian marine deposits are the typical setting where you’ll find trilobite fossils. The other options don’t fit as well. Late Cretaceous terrestrial deposits are from a much later time and represent land environments, where trilobites are not present. Permian desert deposits reflect arid, non-marine conditions, and although trilobites lingered into the Paleozoic, they are not characteristic of desert sediments. Devonian reef deposits are marine, but trilobites are most emblematic of Cambrian marine rocks, where they were especially diverse and widespread.

Trilobites are strong indicators of early Paleozoic marine environments, with their fossils most abundant in Cambrian rocks. They were abundant in shallow seas during the Cambrian, and their hard, mineralized exoskeletons fossilize well in marine sediment, so Cambrian marine deposits are the typical setting where you’ll find trilobite fossils.

The other options don’t fit as well. Late Cretaceous terrestrial deposits are from a much later time and represent land environments, where trilobites are not present. Permian desert deposits reflect arid, non-marine conditions, and although trilobites lingered into the Paleozoic, they are not characteristic of desert sediments. Devonian reef deposits are marine, but trilobites are most emblematic of Cambrian marine rocks, where they were especially diverse and widespread.