Bold terms Gastropoda and some mollusca stuff

Question 1

Class Polyplacophora Late Cambrian- recent

Answer 1

Inhabit rocky marine shorelines.
Consist of Eight Plates
Grasers/ feed on algal

Question 2

Class gastropoda Early Cambrian - recent

Answer 2

Conispiral shell
Live in/ all environments
Grazers, deposit feeders, predators and suspension feeders
largest Mollusc class

Question 3

Class Cephalopoda Late cambrian - Recent

Answer 3

Strictly marine
predators and scavengers
Visceral mass is U shaped

Question 4

Septa

Answer 4

Chambers in a Cephalopoda

Question 5

Siphuncle

Answer 5

A tube that runs through the center of septa (Nautiloidea) or along the edge (Ammonoidea)

Question 6

Class Scaphopoda Middle Ordovician - recent

Answer 6

Looks like tusks
deposit feeder
Burrow

Question 7

Class Pelecypoda/ Bivalvia

Answer 7

Suspension and deposit feeders

marin and fresh water

Question 8

Morphologic terms describing Gastropoda shells

Answer 8

Aperture –> opening

Apex–> Tip of shell

Columella–> the soild or perforated pillar formed by the inner walls of a helical shell

Inner lip–> inner border of aperture

Operculum (door) –>The plate attached to the foot that acts like a door when the gastropod runs into its shell

outer lip –> outer border of the aperture

Shoulder –> Any angularity in the whorl

Whorl –> produced by one rotation of the shell about the coling axis

The ultimate whorl –> 360^o whorl starting from the aperture where the gastropoda lives

Dextral vs Sinistral –> hold shell with apex up and aperture toward yourself. if aperture is on the rigth its DEXTRAL if its on the left SINISTRAL.

Question 9

Modern Gastropods are divided into three subclasses. What are they?

Answer 9

1. Opisthobranchia –> poor fossil record
2. Pulmonata–> mainly terrestrial or fresh water
3. Prosobranchia –> good fosil record and are marine

Question 10

We will focos on Prosobranchia. what are the grades

Answer 10

Grade “Archaeo”gastropoda Cambrian - recent

Grade “Meso”gastropoda Ordovician- recent

grade “Neo”gastropoda Cretaceous - Recent

Question 11

Gread “Archaeo”gastropoda

Answer 11

Always includes limpods (chinees hats)

there short and stubby with a squished aperture

Some have a slit. If they have a slit and its filled in b/c the Archaeogastropoda grew its called a Selenizone

Other have holes or Tremata or a single hole called a trema

some also posses nacre/ mother of pearl

Question 12

Selenizone

Answer 12

The slit in a archaeogoastoropoda fills in as the ultimate whorl moves/ the shell grows

Question 13

Tremata

Answer 13

Holes in an archaeogastropoda’s shell. LIke the slit it allows for wast water to leave the shell at anagle over the gastopods head instied of directly on the archaeogastropoda’s head

favor higher energy settings but low terbidity

live on the substate

Question 14

Grade “Meso”gastropoda

Answer 14

Very curcular aperture

lack a selenizone and a siphonal canal/ notch

Question 15

Gread “Neo”gastropoda

Answer 15

Have a siphonal notch or canal

used to focase inhalant current