Cambrian Animals

3. The phylum containing jointed-legged animals that dominated Cambrian ecosystems
8. The tooth-lined tongue used by early mollusks to scrape food from surfaces
11. The "abnormal shrimp" and top predator of the Cambrian seas with circular mouthparts
12. Hard external covering that first appeared in many lineages during this era
14. The most common fossil found in the Burgess Shale often called a lace crab
15. Marine animal with two shells that looks like a clam but has different internal anatomy
16. Small slug-like animal covered in carbonaceous scales and long defensive spines
17. Important fossil site in China offering a window into early Cambrian diversity
19. Predatory marine worms named after a Greek fertility god known for their burrowing
20. Famous shale formation in Canada containing exceptionally preserved Cambrian fossils
21. Five-eyed creature with a long flexible proboscis ending in a claw

1. Individual units that make up the compound eyes of early arthropods
2. Group of "legged worms" that includes the ancestors of modern velvet worms
4. Iconic hard-shelled arthropod with a three-lobed body structure
5. Group of soft-bodied animals including the ancestors of snails and squids
6. Tentacled creature with a conical shell and a lid-like operculum
7. Primitive chordate thought to be one of the earliest ancestors of vertebrates
9. Spiny worm-like animal once reconstructed upside down due to its bizarre appearance
10. Early sponge-like organisms that helped build the first complex reefs
13. Microscopic reproductive units from early land plants that began appearing late in this era
18. The geological period known for the rapid "explosion" of complex life forms