Spiralians 1: Lophorates - Brachiopods (Chapter 12)

Question 1

Spiralian invertebrate

Answer 1

• organisms with initial sequence of cell division that follows a spiral track
• triploblastic body plan
• protostomes
• includes mollusks, annelids, brachiopods, & most flat worm

Question 2

Lophophorate

Answer 2

• specialized feeding & respiratory organ found in brachiopods & bryozoans
• its tentacles move water into mouth & act as filter for food

Question 3

Brachiopoda

Answer 3

• bilaterally symmetry in each shell
• 2-shelled organisms with lophophorate
• solitary lifestyle but do cluster together as a population

Question 4

Brachipods - soft tissues

Answer 4

• internal
• lophophore
• mouth, gut, anus
• nephridium - kidney-like organ
• muscles = used to open the shell
• external muscles: pedicle (movement) & setae (holding in place)

Question 5

Brachial (dorsal) valve

Answer 5

smaller, contains cardinal process

Question 6

Pedicle (ventral) valve

Answer 6

• bigger, with deltidial plates & teeth, foramen
• useful for taxinomic identification

Question 7

Linguliformea

Answer 7

• a subphylum of Brachiopoda with characteristic organo-phosphate shell
• harsh to low oxygen environment
• planktonic larval stage

Question 8

Craniformea

Answer 8

• subphylum of Brachiopoda with organo-carbonate shell
• not common
• nectobenthic larval stage
• Cambrian to Recent

Question 9

Rhynchonelliformea/ Articulate Brachiopods

Answer 9

• subphylum of Brachiopoda with calcitic shell
• extremely abundant in Paleozoic
• strictly marine, sessile epifauna

Question 10

Brachiopods - hard tissues

Answer 10

• 2 shells
• internal shell structures: fibrous vs. laminated shells vs. cross laminated vs. punctuated (holed)
• hinges, teeth, sockets, cardinal process
• external shell features: smooth or plication