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:
Match the following findings with Tribrachidium's relationship to echinoderms:
Match the following findings with Tribrachidium's relationship to echinoderms:
What is one of the major mysteries surrounding echinoderms?
What is one of the major mysteries surrounding echinoderms?
Why have paleontologists been unable to conclusively identify an ancestor of echinoderms?
Why have paleontologists been unable to conclusively identify an ancestor of echinoderms?
Why was Tribrachidium initially suggested as a candidate for an ancestral echinoderm?
Why was Tribrachidium initially suggested as a candidate for an ancestral echinoderm?
Why was Tribrachidium eventually discounted as an ancestral echinoderm?
Why was Tribrachidium eventually discounted as an ancestral echinoderm?
What is the significance of placing Tribrachidium in its own phylum, Trilobozoa?
What is the significance of placing Tribrachidium in its own phylum, Trilobozoa?
