Belemnites

Question 1

Class and phylum

Answer 1

Mollusca

Cephalopoda

Question 2

Describe morphology of belemnite

Answer 2

Solid guard is preserved, bullet shaped calcite mass, conical cavity in anterior is phragmocone, chambers used for buoyancy, adjusted volume of gas via siphuncle, guard is counterbalance to tentacles, proostracum is extension of gaurd may be preserved.

Question 3

Mode of life?

Answer 3

Swam like squid, nektonic, swim vertically and horizontally, movement controlled by gas and tentacles, and jet propulsion. When dies, fell to sea floor and aligned as paleocurrent indicators in death assemblage

Question 4

What is the phragmocone?

Answer 4

Empty chambers and anterior body chamber within the soft tissue, chambers linked via siphuncle

Question 5

What is the protoconch?

Answer 5

First chamber