W8 Brachiopods and Bivalves

Question 1

Bivalves deutsch

Answer 1

zweischalige Muschel

Question 2

Brachiopods deutsch

Answer 2

armfüßler

Question 3

Brachiopods and bivalves habitat

Answer 3

inhabit similar habitats (be
benthic
live on sea floor

Question 4

Brachiopods and bivalves shell morphology

Answer 4

similar shell morphology (convergent evolution)
relatively simple shells allow interpretation of function and mode of life
two shells that close smth within
biologically / genetically they are two distinc animal phyla

Question 5

Brachiopods and bivalves phyla same?

Answer 5

differnt phyla

Question 6

Brachiopods and bivalves geological history

Answer 6

contrasting geological histories

brachiopods abundant in palaeozoic vs. bivalves after paleozoic

Question 7

Phylum Brachiopoda symmetry

Answer 7

bilaterally symmetrical

Question 8

Phylum Brachiopoda feeder type

Answer 8

filter feeder

benthic ,marine animals

Question 9

Phylum Brachiopoda shell

Answer 9

bivavled (two shells) , calcaerous (calcite) or chitinophosphatic shells
– outer organic layer (periostracum)
– inner mineral layers + organic materials
• sessile - +/- attached (pedicle)
• lophophore (feeding, gills), feathery structure
three pairs of muscle scars
adductor, adjustor and diductor muscle

Question 10

Phylum Brachiopoda time

Answer 10

early cambrian till present

dominant sea shell in palaeozoic

Question 11

Brachiopods classification (classes)

Answer 11

Class Lingulata
no shell articulation, organophosphate shell
Class Calciata
calcareous (calcite) shell

Question 12

Brachiopods groups

Answer 12

linguliforms
phosphatic shell (different mineralogy anf colour) 
actually does not  have precise teeth and sockets bcs lives in burrows, sort of pulled down in seafloor
“living fossil” bcs general shape hasnt changed

Question 13

Lunguli mode of life and conditions

Answer 13

Lunguli forms “lagoon” margin bcs thats where best conditions
subject to light (energy), nutrients (plankton)
plankton also need micronutrients ex. thru sandstorms
find it difficult to lie in muddy conditions

Question 14

Brachiopod Evolutionary History

Answer 14

Fortunes of different brachiopod groups have waxed and wayned through time
Permian Mass Extinction affected brachiopods quite strongly

Question 15

Phylum Mollusca symmetry

Answer 15

bilaterally symmetrical

Question 16

Phylum Mollusca segemnattion

Answer 16

unsegmented

Question 17

Molluscula skeleton

Answer 17

extermal or secondarily calcaerous skeleton
mantle - outfolding of body wall
• radula - rasping feeding organ

Question 18

Phylum Mollusca deutsch

Answer 18

Weichtiere

Question 19

Molluscan diversity

Answer 19

Molluscan diversity

Gastropods with coiled, chamber structure (can be high spired), widely distributed (everywhere!) adapt

Question 20

Phylum Mollusca, Class Bivalvia

Answer 20

Bivalve: an aquatic mollusc which has a compressed body enclosed within a hinged shell, such as oysters, mussels, and scallops.

Question 21

Bivalve shell

Answer 21

bivalved calcareous shells (usually aragonite, but also calcite or both)
shell completely encloses the soft parts (protection) can see attachement points

Question 22

Bivalve hinge

Answer 22

articulated hinge

Question 23

Bivalve mode of life

Answer 23

variable modes of life - epifaunal, infaunal, attached, swimming,
reef-forming

Question 24

epifaunal definition

Answer 24

Aquatic animals, such as starfish, flounder, or barnacles, that live on the surface of a sea or lake bottom or on the surface of a submerged substrate, such as rocks or aquatic plants and animals, but that do not burrow into or beneath the surface.

Question 25

infaunal definition

Answer 25

Aquatic animals, such as starfish, flounder, or barnacles, that live on the surface of a sea or lake bottom or on the surface of a submerged substrate, such as rocks or aquatic plants and animals, but that do not burrow into or beneath the surface.

Question 26

Bivalve feeders

Answer 26

suspension and deposit feeders

Question 27

Bivalve life time

Answer 27

Cambrian- Present

• dominant ‘sea shells’ in Mesozoic and Cenozoic

Question 28

Bivalve ligament

Answer 28

pit with organic ligament thats continuously causing shells to spring apart so only need one set of muscles that closes the cell (bcs automatically open)

Question 29

Bivalve siphons

Answer 29

an be extremely long and allow bivalves to live in burrow (protection) and gets food through siphons
when siphons are retracted there has to be a fold for it to retract into
only burrow bivalves need these siphons
siphons accomodated in shell

Question 30

Functional Morphology

Answer 30

mode of life inferences based on morphology
form reflects function
so a change in function would also lead to change in form

Question 31

morphological features multiple functions

Answer 31

multiple effeect facor

however some features are neutral

Question 32

convergent evolution

Answer 32

support from observations of convergent evolution

– unrelated groups converge on similar morphologies

Question 33

functional morphology interpretations based on

Answer 33

analogy and nearest living relative analysis
– biomechanical modelling (jaw strength etc.)
– other palaeontological/geological evidence (trace fossils, etc.)
bivalves are actually good example

Question 34

Burrowing Bivalves

Answer 34

adapted to living and moving up and down in a burrow

have siphon to catch

Question 35

Oysters

Answer 35

epifaunal, attached (cemented)
build off of each others shells, cement on top each other
almost line of symmetry down middle of shell

Question 36

Mussels

Answer 36

functional morphology

epifaunal, byssally-attached bivalves (mussels)

Question 37

Rudist Bivalves

Answer 37

look like cone coral

cemented