These organisms’ eyes possessed calcite lenses and were some of the first examples of compound eyes. For 10 points each:
[10m] Identify this class of extinct ancient marine arthropods. They contain a hard exoskeleton and have a body divided into three sections.
ANSWER: trilobites [or Trilobita]
[10e] Trilobites first evolved during this geological period where most extant animal phyla emerged. This geological period saw the rapid diversification of life in its namesake “explosion.”
ANSWER: Cambrian period [accept the Cambrian explosion]
[10h] Because of their wide distribution and sudden appearance, trilobites are often used as these types of standard fossils. These fossils are contrasted with zone fossil, which help determine a fossil’s biozone.
ANSWER: index fossils [accept guide or indicator fossils]
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