UC Berkeley
Take a good look at the fossil and reconstruction of Sanctacaris. Then compare what you see to the arthropod checklist below.
Use your mouse to hover over the image and zoom in. (Touch the image on a mobile device.)
Does it look like Sanctacaris inherited all of the characters of an arthropod?
- arthropod characters
- bilateral symmetry
- segmented body
- hard exoskeleton
- jointed legs
- many pairs of legs
Based on the available evidence, is Sanctacaris part of the arthropod lineage?
Yes No
Nice try, but maybe it would have helped if you had seen the hint:
- Does it look like it has a hard exoskeleton — like it's wearing armor?
- Do the visible appendages seem to be jointed? Are there a lot of them?
- Is its body segmented?
If you can answer yes to these questions, then you might hypothesize that Sanctacaris was an arthropod.
Try again.
Get a hint
- Does it look like it has a hard exoskeleton — like it's wearing armor?
- Do the visible appendages seem to be jointed? Are there a lot of them?
- Is its body segmented?
If you can answer yes to these questions, then you might hypothesize that Sanctacaris was an arthropod.