The Lophophorates

Question 1

lophophorate

Answer 1

posses a lophophore

filter feeders

Question 2

A lophophore

Answer 2

A feeding organism that surrounds the mouth. A ring of hollow tentacles with cillia that generate a feeding current. The anus is outside of the ring

Question 3

Brachiopods

Answer 3

Have 2 valves but are not “bivalves”
“Arm foot”
Relatively minor phyla in modern oceans.
Low nutrient habitats
Benthic filter feeders
Nearly all sessile epifaunal
Probably the most common fossil-the dominant paleozoic form

Question 4

Brachiopod morphology

Answer 4

Shell made up of 2 valves secreted by an underlying mantle.
pedicle
Grows at margin valves
Commisure
Posterior end may or may not have a hinge or pedicle

Question 5

pedicle

Answer 5

Fleshy extension of the body used to attach brachiopods to rocks.

Question 6

Symmetry of brachiopods

Answer 6

Valves are not symmetrical to eachother, but ther is bilatteral symmetry in the valves themselves

Question 7

Internal anatomy of a brachiopod

Answer 7

*Most of the interior shell occupied by mantle cavity- not much to eat
*Lophophore sits in mantle cavity, attached to dorsal valve
Lophophore can be supported by a calcareous structure (brachidium)
*Have muscles for both opening and closing

Question 8

Brachidium

Answer 8

A calcareous structure in bivalves that supports the lophophore

Question 9

Composition of a brachiopod shell

Answer 9

• Organophosphatic (calcium phosphate and organic matter)

* Calcite

Question 10

An inarticulate bivalve

Answer 10

A bivalve that lacks an articulation hinge

Question 11

astrophic

Answer 11

Not having a well defined hinge line.

Question 12

strophic

Answer 12

Having an elongated well defined hinge line.

Question 13

pedicle opening

Answer 13

Aperture or slit from which the pedicle extends.

Question 14

Interarea

Answer 14

Surface of a valve between the beak and hinge line; typically bears the pedicle opening.

Question 15

teeth of brachiopods

Answer 15

Knob like protrusions (teeth) on the hinge of the pedicle valve fits into the small depressions (sockets) on the hinge of the brachial valve.

Question 16

lingula

Answer 16

living brachiopod group. Called a “living fossil”

Question 17

diductor scars

Answer 17

Mark the attachment sites of valve opening muscles in brachiopods.

Question 18

Cardinal process

Answer 18

Know at the midline of brachial valvve interior to which the diductor muscles attach.

Question 19

Rhynochonelliforms

Answer 19

Brachiopods. Articulate with a calcareous shell

Question 20

Linguliforms

Answer 20

Brachiopods. Organophosphatic. Inarticulate.

Question 21

Craniiformea

Answer 21

Brachiopods. Calcareous, no hinge (inartiuclate). Cement lower valvue to something. “skull” formed by muscle scars

Question 22

Articulate

Answer 22

Brachiopods with a hinge

Question 23

Inarticulate

Answer 23

Brachiopods without a hinge

Question 24

Fossil Record of brachiopods

Answer 24

Start in Cambrian. Bulge from Ordovician-Permean. End of the Permean the number goes way down a never recovers (95% become extinct)

Question 25

Ancestry of brachiopods

Answer 25

Unclear

Question 26

Paleontological issues with brachiopods

Answer 26

+ancestry unclear.
+Why were they hurt by the permo-Triassic extinction?
+Why have they not bounced back?
+How are subphyla,classes and orders related?

Question 27

Speculations of why brachiopods have never bounced back in modern times?

Answer 27

competition? low speciation rates? Increased productivity in oceans? Durophagy (shell eating)?

Question 28

Bryozoa

Answer 28

Lophophorates. Living groups. Relation to brachiopods is unknown. Live as a colony. Made of asexually proliferated units call zooids. Budded from 1 single ancestral zooid. Filter feeders. Common and diverse in the oceans. Colonies can be immerse, sometimes >1m.

Question 29

zooid

Answer 29

<1 mm in size. Body wall can be calcified (zoecium)

Question 30

zoecium

Answer 30

Calcified body wall of a zooid

Question 31

Lophophore in bryozoa

Answer 31

Can be extruded and retracted. May have an operculum to cover lophophore opening, or they may have muscles that can contract and shoot out the lophophore.

Question 32

How many bryozoa live in a community?

Answer 32

Can be millions in a colony

Question 33

Skeletons of bryozoa

Answer 33

Can be completely organic and flexible, or partly mineralized and still flexible, or completely mineralized and therefore rigid.

Question 34

Bryozoa first appearance in the fossil record

Answer 34

First appear in the late cambrian.