Podcast
Questions and Answers
Match the following time period with the appearance of the first clearly recognizable echinoderms:
Match the following time period with the appearance of the first clearly recognizable echinoderms:
Cambrian period = 540 million years ago Ediacaran period = Just before the Cambrian
Match the following characteristics with Tribrachidium:
Match the following characteristics with Tribrachidium:
Round, flat, disc-shaped fossil = Tribrachidium Triradial (three-point) symmetry = Tribrachidium
Match the following descriptions with the radial body plan:
Match the following descriptions with the radial body plan:
Symmetrically arranged parts around the center = Radial body plan Parts arranged like the petals of a flower = Radial body plan
Match the following statements with Tribrachidium's classification:
Match the following statements with Tribrachidium's classification:
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Match the following findings with Tribrachidium's relationship to echinoderms:
Match the following findings with Tribrachidium's relationship to echinoderms:
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What is one of the major mysteries surrounding echinoderms?
What is one of the major mysteries surrounding echinoderms?
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Why have paleontologists been unable to conclusively identify an ancestor of echinoderms?
Why have paleontologists been unable to conclusively identify an ancestor of echinoderms?
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Why was Tribrachidium initially suggested as a candidate for an ancestral echinoderm?
Why was Tribrachidium initially suggested as a candidate for an ancestral echinoderm?
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Why was Tribrachidium eventually discounted as an ancestral echinoderm?
Why was Tribrachidium eventually discounted as an ancestral echinoderm?
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What is the significance of placing Tribrachidium in its own phylum, Trilobozoa?
What is the significance of placing Tribrachidium in its own phylum, Trilobozoa?
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