Chordata Flashcards
1
Q
What are the three clades in Chordata? Which are invertebrates?
A
Lancelets (Cephalochordata) (invertebrate)
Tunicates (Tunicata) (invertebrate)
Vertebrata
2
Q
Defining Characteristics
A
- Notochord
- Dorsal hollow nerve cord
- Endostyle
- Post-anal tail
- Pharyngeal gill slits
- Deuterostomes
3
Q
Defining Characteristics
A
- Notochord
- Dorsal hollow nerve cord
- Endostyle
- Post-anal tail
- Pharyngeal gill slits
- Deuterostomes
4
Q
Synapomorphies of Lancelets (Cephalochordata)
A
- Neural crest cells nonmigratory
- Pharyngeal (tongue) bars divide slits
- Many sets of paired gonads
- Buccal cirri surrounding oral hood
- Segmented muscles
- Filter feeder
- ALL Chordate characteristics
5
Q
Synapomorphies of Sea Squires (Tunicates)
A
- Outer tunic
- Sessile adults in certain groups
- Primitive neural crest cells in tadpole larva
- Chordate characteristics in larval stage
6
Q
What are the two clades within vertebrata?
A
1) Cyclostomata
2) Gnathostomata
7
Q
Synapomorphies of Vertebrata
A
- Vertebral column
- Migratory neural crest tissue
- Distinct cranium
- One or more semicircular canals (inner ear)
- Gill arches
8
Q
Name three CRANIATES (animals with skulls)
A
1) Hagfish
2) Lamprey
3) Gnathostome / Shark
9
Q
What are the two clades within Agnatha?
A
1) Myxini
2) Petromyzontida
10
Q
Synapomorphies of Cyclostomes
A
- Notochord
- Elongated eel-like body
- Single nostril for respiration / olfaction
- Tongue with horny tooth plates
11
Q
Symplesiomorphies of Cyclostomes
A
- Lack jaws
- True gill arches supported by cartilage (pore-like)
- Distinct cranium (cartilaginous)
12
Q
Hagfish (Myxini / Myxiniformes) Synapomorphies
A
- Secondarily lost vertebrae
- Continuous caudal fin
- One semicircular canal
- Multiple external mucus glands
- Multiple hearts
- Mouth surrounded by barbels
13
Q
Lamprey (Petromyzontida / Petromyzontiformes) Synapomorphies
A
- Parasitism in some adults
- Prolonged larval stage (ammocoete)
- No true teeth (horny epidermal teeth)
- Two semicircular canals
- 1-2 dorsal fins supported by cartilage
- Some anadromous (river - sea)
- Filter feeder / benthic
