Paleozoic Vertebrate Evolution

Question 1

What are the Characteristics of a Chordate

Answer 1

at some point their life cycle every Chordate will have a:
- Dorsal Hollow
- Notochord
- Pharyngeal (gill) splits

Question 2

what are the other characteristics of Chordate

Answer 2

• post-anal tail
• head region
• all soft tissue

Question 3

Define early Chordates

Answer 3

• were soft bodied
• 5cm long
• 525 million years old

Question 4

What is the Anatolepis

Answer 4

putative early jawless fish represented by phosphatic plates

Question 5

What are the oldest vertebrates

Answer 5

Arandaspids

Question 6

Define Ostracoderms

Answer 6

Name means “bony skin”
- armored jawless fish
- middle Ordovician to end of Devonian
-emergence of paired fins

Question 7

Define Placoderms

Answer 7

Name means “Plante-skinned”
- Silurian to end of Devonian
- armored head and shoulder
-soft body

Question 8

Who was the key to understanding origin of jaws and teeth

Answer 8

Placoderms
- had “teeth”
-double hinged jaws
-variety of diets and ways of eating

Question 9

Define Acanthodians

Answer 9

• had large spines and scales covering much of body
• Silurian to Permian
• most abundant in the Devonian
• early relatives of modern sharks

Question 10

When did Body fish evolve

Answer 10

During the Devonian

Question 11

what are the two groups of body fish

Answer 11

1. Ray-finned fish
2. Lobe-finned fish

Question 12

Define Ray-Finned fish

Answer 12

have musculature and bones extending into the fins
- most diverse group of vertebrates today
- 99% of modern fish

Question 13

Define Lobe-finned fish

Answer 13

have small bones that support the fin

Question 14

Define a Coelacanth

Answer 14

Previously thought to be extinct until a fisherman found one