Crinoid Flashcards

HideShow resource information
Phylum
Echinodermata
1 of 20
Class
Crinoidea
2 of 20
Water vascular system
Hydraulic system that allows the animal to extend its tube feet by forcing water into its tissues.
3 of 20
5-fold symmetry
5 planes of symmetry, each giving a mirror image. These form a radial pattern.
4 of 20
Test
Made of Calcareous plates
5 of 20
Radial Plates
On Calyx- point of attachment for arms.
6 of 20
Basal Plates
On Calyx- structural
7 of 20
Infrabasal Plates
On Calyx- attach Calyx to stem
8 of 20
Evolution
first evolved in Ordovician. Peaked in Upper Paleozoic(early Carboniferous). Are extant.
9 of 20
Environment
Moderate energy(filter feeders) Above and below photic zone.
10 of 20
Mode of Life
Either sessile(stemmed, Holdfast attached to seabed) or nektonic. Fossil Crinoids mostly stemmed, attached. Presently found at all water depths.
11 of 20
Brachia
Delicate structures that waft in currents and use cilia to collect food particles. flexible arms.
12 of 20
Calyx
Main part of Crinoid which houses soft tissue. Cup made up of calcareous plates(Infrabasal, Basal, Radial) showing 5-fold symmetry.
13 of 20
Stem
Made of calcite plates(Ossicles) with centres linked together with soft tissue.
14 of 20
Holdfast
Attaches to substrate On hard substrate secretes cement to attach at base of stem.
15 of 20
Anal Tube
Protrudes from centre of Calyx. Gets rid of waste without it mixing with fresh water.
16 of 20
Membrane
Soft tissue covering animal to protect calcite. Flexible, decays on death (Crinoid becomes disarticulated)
17 of 20
Feeding
Pinnules of Brachia catch food particles which get passed down food grooves by cilia into mouth.
18 of 20
Tegmen
For feeding. On top of Calyx and hosts mouth in centre. 5 radial food grooves and **** on side.
19 of 20
Ossicle
Calcite plate making up part of the stem.
20 of 20

Other cards in this set

Card 2

Front

Crinoidea

Back

Class

Card 3

Front

Hydraulic system that allows the animal to extend its tube feet by forcing water into its tissues.

Back

Preview of the back of card 3

Card 4

Front

5 planes of symmetry, each giving a mirror image. These form a radial pattern.

Back

Preview of the back of card 4

Card 5

Front

Made of Calcareous plates

Back

Preview of the back of card 5
View more cards

Comments

No comments have yet been made

Similar Geology resources:

See all Geology resources »See all Morphology of fossils resources »