Jawless Fish —> Amphibians

Question 1

Craniates

Answer 1

“chordates with a head”
*neural crest (sensory, frontal area of skull) -> increase in brain size -> increase behavior complexity -> increase metabolism-> *2 chambered heart

Question 2

Most primitive class of Craniates

Answer 2

Myxini (hagfish), slime=adaptation to predation
scavengers, jawless

Question 3

Vertebrates

Answer 3

“craniates with a vertebral column”
greater support—> support fins

Question 4

Most primitive class of Vertebrates

Answer 4

Petromyzontida (lamprey)
jawless, fluid-feeding parasites

Question 5

Gnathostomes

Answer 5

“vertebrates with calcified teeth and jaw”
enlarged fore-brain & lateral line (detects pressure waves/movement)

Question 6

Most primitive class of Gnathostomes

Answer 6

Chondrichthyes (sharks/rays)
450 mya, predators

Question 7

Osteichthyans

Answer 7

“Gnathostomes with calcified endoskeleton”
Operculum= covers gills
Swim Bladder= buoyancy control

Question 8

Most primitive class of Osteichthyans

Answer 8

Actinopterygii (bony fish)
400 mya

Question 9

Lobe-fins

Answer 9

“Osteichthyans with muscularized pelvic & pectoral find with rod shaped bones”

Question 10

Most primitive class of Lobe-fins

Answer 10

Sarcopterygii (lobe-fin fishes)
coelacanths & lung fish (minimal gas exchange- swim bladder)
•form capable of invading land “walking”

Question 11

Tetrapods

Answer 11

“4 limbs and digits”
neck= allows head and body to move independently

Question 13

Class Amphibia order

Answer 13

Urodela- salamanders
Anura- frogs
Apoda- caecilians

Question 14

Class Amphibia characteristics

Answer 14

3 chambered heart, respiration through lungs & skin, tied to water due to desiccation and reproduction

Question 15

Most primitive class of Tetrapods

Answer 15

Amphibia (365 mya)
Tiktaalik—> link between lobe-fins and tetrapods (evolution carpel bones= wrist)