Cnidarians

Question 1

How are solitary corallites formed?

Answer 1

polyps which live an individual existence and do not form part of a colony

Question 2

Where can many solitary corals be found among?

Answer 2

Rugosa and Scleractinia (extinct solitary corals)

Question 3

How are colonies produced from an individual founding polyp?

Answer 3

asexual reproduction

Question 4

What is the advantage to coral colonies forming?

Answer 4

capacity for increased size and stability and greater efficiency in feeding and other major life processes

Question 5

What are the skeletons secreted by colonial corals said to be?

Answer 5

Compound (leading to widely variable morphology)

Question 6

What are some examples of Cateniforms?

Answer 6

Halysites; Tabulate

Question 7

What are Canteniforms like?

Answer 7

corallites are joined laterally to form palisades

Question 8

Would do horizontal section of canteniforms resemble?

Answer 8

links in a chain

Question 9

What are some examples of Cerioids?

Answer 9

Lonsdaelia; Rugosa

Question 10

What are Cerioids?

Answer 10

walls of the adjacent corallites are joined to produce a polygonal pattern in cross section

Question 11

What is an example of a phaceloid?

Answer 11

Syringopora; Tabulata

Question 12

What are phaceloids?

Answer 12

a type of fasciculate coral in which the cylindrical corallites are approximately parallel with each other

Question 13

What is an example of Thamnasteroid?

Answer 13

Phillipsastraea; Rugosa

Question 14

What are Thamnasteroids?

Answer 14

absence of Epithecal so the septa (walls/plates) adjacent corallites join each other

Question 15

What is the common growth forms of Thamnasteroids?

Answer 15

Scleractinian corals (also in extinct rugose corals)

Question 16

What do rugose corals show?

Answer 16

degree of bilateral symmetry since the metasepta are only inserted in 4 areas

Question 17

What can obscure the bilateral symmetry of rugose corals?

Answer 17

the large number of septa

Question 18

What are the characteristics of most rugosa corals?

Answer 18

Well developed septa
Dessepiments and tabulae
Columella or other axial structure

Question 19

What is the epitheca (upper of coral) like for rugosa corals?

Answer 19

almost always prominent and generally thick and wrinkled

Question 20

What were rugosa like between the middle Ordovician and the lower Llandovery?

Answer 20

Most species small and solitary

Question 20

When did rugosa occur?

Answer 20

Middle Cambrian
(but typical examples not till middle Ordovician)

Question 21

What took place in the Silurian regarding rogusa?

Answer 21

diversification that meant rugosa became an important element of reef faunas

Question 22

When did rugosa start to decline?

Answer 22

in the later carboniferous and then persisted till extinction at the end of the Permian

Question 23

Are Tabulates solitary or colonial?

Answer 23

Colonial

Question 24

What are the characteristics of Tabulates?

Answer 24

corallites are usually small with prominent tabulae Septa reduced or absent

Question 25

What is coenosteum?

Answer 25

skeletal tissue between the corallites secreted by a sheet of tissue that joined the polyps in life

Question 26

When are Tabulates thought to have occured?

Answer 26

Cambrian but undoubted presence in the lower Ordovician

Question 27

When were are tabulates extinct?

Answer 27

By the end of the permian

Question 28

What corals does the Scleractinia order cover?

Answer 28

All post lower Triassic corals

Question 29

How can Scleractinia be distinguished from Rugosa?

Answer 29

Septal insertion

Question 30

What is septa insertion like for Scleractinia?

Answer 30

Inserted in multiples of six each insertion cycle must be completed before the next cycle

Question 31

What is the epitheca like in Scleractinia?

Answer 31

poorly developed or absent

Question 32

What is the skeletal composition of Scleractinia?

Answer 32

Aragonites (with other corals being low-Mg calcite)

Question 33

What did Scleractinia evolve from?

Answer 33

A soft bodied organism instead of Rugosa or Tabulate