Mollusks

Question 1

General Characteristics

Answer 1

Mantle cavity
Calcarous radula - tounge used for feeding
Muscular foot - locomotion
Gills
Spicules or shells - aragonitic
Open circulatory system

Question 2

Polyplacophorans

Answer 2

Cambrian to recent
Made of 8 plates
Foot clamps against substrate

Question 3

Monoplacophorans

Answer 3

Cambrian to recent (peak in Devonian)
One plate - aragonitic
Wastebasket group

Question 4

Gastropoda

Answer 4

Cambrian to recent
“stomach foot”
ontogenetic rotation of shell - torsion
radula can lick though shells of other snails

Question 5

Nautiloidea

Answer 5

Cambrian to recent
Straight or coiled shell
Four gills + living chamber
Phragmocone - chambered shell

Question 6

Coleoidea

Answer 6

Devonian to recent
internal shell or no shell
belemnites + octopods + squids + cuttlefish

Question 7

Belemnites

Answer 7

Triassic to Cretaceous
Cephalopod with 10 arms
3 part internal shell
Fossils typically found in large groups

Question 8

Squids

Answer 8

Cretaceous to recent
8 arms, 2 tentacles
Chitinous pen provides support
Little/no biomineralization

Question 9

Octopodes

Answer 9

Middle Jurassic to recent
8 arms
Chitinous beak - no other hard parts

Question 10

Cuttlefish

Answer 10

Late Cretaceous to recent
8 arms, 2 tentacles
Cuttlebone - CaCO3 - aragonite

Question 11

Ammonoidea

Question 12

Ammoniods

Question 13

Nautiloids