Crinoids Flashcards
1
Q
Phylum and class
A
Echinodermata as have 5 fold symmetry
Crinoidea
2
Q
What are the four main parts?
A
Holdfast, stem, calyx, brachia
3
Q
What is the calyx?
A
Contains soft part of the animal, cup made of flat calcareous plates.
4
Q
What are the brachia?
A
Flexible arms of the Crinoids, may branch and have a groove lines with cringe feet to trap food particles and pass down to mouth in calyx
5
Q
How is the stem assembled?
A
Made from ossicles, disc like plate which have a hole in centre, so joined by strong soft tissue that allow stem to be flexible, means animal is disarticulated upon death
6
Q
What is the mode of life?
A
Sessile or nektonic, filter feeders,
7
Q
Time period?
A
Ordivician-Present
