Brachiopods

Question 1

Phylum

Answer 1

Brachipoda

Question 2

What time period

Answer 2

Cambrian, widespread and dominant in palaeozoic, still alive today but losses in Permian extinction and Triassic

Question 3

Composition of shells?

Answer 3

Chitin and calcium phosphate

Question 4

Describe morphology of a Brachipod

Answer 4

Bilateral symmetry of valves, symmetrical if centrally bisected, valves uneven size, pedicle larger that brachial, pedicle may be present from foramen, attachment. Brachial valve contains lophophore

Question 5

What is the lophophore?

Answer 5

Fluid filled set of filaments lined with cilia that generate currents to enable food particles to be trapped

Question 6

How does Brachipod shell form?

Answer 6

Shell secretes by soft tissue of the mantle

Question 7

How do Brachipods feed?

Answer 7

All are filter feeders, feed via lophophore, fluid filled, lined with cilia, beat to generate currents, brings in fresh water and removes wasted time as bet to trap particles passed down groove to mouth, separate water already filtered from fresh via fold in edge of the shell

Question 8

How do Brachipods open and close valves?

Answer 8

Open valves to let fresh water in, by contracting diductor muscles, attached via cardinal processor brachial valve and central part of pedicle valve. To close adductor muscles contract, attached to central parts of both valves leave muscle scar

Question 9

How are Brachipods adapted to turbulent water?

Answer 9

Large pedicle opening for attachment
Strongly ribbed valves
Folded margin
Thick heavy shell

Question 10

How are Brachipods adapted to quiet water?

Answer 10

Median fold or suculus to separate currents
Extension of valves to form wings
Smooth if weakly robbed
No pedicle opening

Question 11

How are Brachipods adapted to soft muddy substrate?

Answer 11

Valves with large flat resting area

One margin upturned to ensure shell remains out if sediment for feeding

Question 12

How are rhynconellids adapted?

Answer 12

Ordivician to recent, abundant in Mesozoic a strophic curbed hinge, short, strongly ribbed, small pedicle foramen, zigzag commisure, strong fold and sulcus

Question 13

How are spiriferids adapted?

Answer 13

Ordovician-Jurassic Strophic hinge, long, winged, fold and sulcus, spiral lophophore support, sessile, not attached common in Carboniferous

Question 14

How are productids adapted?

Answer 14

Devonian to Permian
Wide geological range, semicircular shell, thick strophic convex pedicle valve brachial valve is flat radiating ribs, hollow tubular spines

Question 15

How are terbratulids adapted?

Answer 15

Devonian to now
Common in Jurassic and Cretaceous, astrophic hinge, short, pedicle foramen, smooth valves, streamlined could be high energy