Graptolites

Across

• 1. Each individual branch of the rhabdosome is know as? (5)
• 4. What is the opening in the skeleton which the zooid protrudes through in order to filter feed called? (8)
• 5. What class are graptolites found in? (14)
• 6. What is the thin extension of sicula used to attach to a floating devise called? (4)
• 7. Which evolved first uniserial or biserial graptolites? (9)