Question


Geologic Time Quick Check
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Question
Which characteristic defines the Paleozoic era?(1 point)
Responses

Reptiles became dominant after a mass extinction.
Reptiles became dominant after a mass extinction.

Simple, one-celled life forms were dominant.
Simple, one-celled life forms were dominant.

Mammals and other warm-blooded animals became dominant.
Mammals and other warm-blooded animals became dominant.

Animals with shells and hard parts were dominant for the first time.

Answers

GPT-4o mini
The characteristic that defines the Paleozoic era is:

**Animals with shells and hard parts were dominant for the first time.**

This era is known for the emergence of many diverse forms of life, particularly during the Cambrian Explosion, which saw the development of hard-shelled organisms.