Lab 14 Outline

Question 1

Subphylum Craniata

Answer 1

1. a cranium protecting the brain and sensory organs
2. 2 to 4 chambered heart and closed circulatory system
3. Cartilage and/or bone
4. complex brain with 10 or 12 pairs of cranial nerves

Question 2

Cyclostomata(=Agnatha)-Jawless Fishes

Answer 2

• no jaws but with round mouths
• eel-like body with no paired fins
• no scales
• cartilaginous skeleton
• notochord present with rudimentary vertebrate

ex: hagfishes and lamprey’s

Question 3

Chondrichthyes

Answer 3

• cartilaginous skeleton with some calcified elements
• many with placoid scales (structurally like teeth)
• paried and median fins

ex: sharks, skates, rays, and ratfishes

Question 4

Gnasthostomata

Answer 4

jawed vertebrates

Question 5

Actinopterygii (ray-finned fishes)

Answer 5

-median and paired fins with fin rays (spines
or soft rays)
-many with scales of three types: ganoid, cycloid, and ctenoid
-many with swim bladder for buoyancy compensation (developed from ancestral lung)

Question 6

Actiniatia - Coelacanths

Answer 6

• thin layer of bone surrounds the vertebral spine and fin rays (coel=hollow; acanth=spines)
• only two exant species
• thought to be extinct until 1938 when Latimeria chalumnae discovered off E. South Africa

Question 7

Dipnoi - Lungfishes

Answer 7

• six extinct species
• only found in south america, africa, and australia
• one or two lungs (invaginations of the gut) are present and used for breathing air

Question 8

Amphibia- Amphibians

Answer 8

• semi-aquatic
• with a moist, glandular skin used in respiration; no scales
• respiration: gills, lungs, skin, buccal cavity
• 2 internal nares open into the mouth cavity
• 3 chambered heart
• Most have a life cycle with metamorphosis
• ectoderms
• main nitrogenous waste as adults is urea

Question 9

Aminotes

Answer 9

tetrapods characterized by the presence of an amniotic egg

Question 10

tetrapods

Answer 10

vertebrates that have four limbs

Question 11

Primary waste material of reptilia

Answer 11

uric acid

Question 12

non-avian reptiles

Answer 12

• keratinous scales; turtles also have fused plates of dermal origin forming the carapace
• with a 3.5 chambered heart (crocodiles have 4)
• many molt their waterproof outer skin
• most forms restricter to life on land
• ectotherms

Question 13

avian reptiles

Answer 13

• body is covered with feathers
• hollow bones
• forelimbs modified into wings
• legs and feet often with scales
• lungs with air sacs
• 4 chambered heart
• endotherms
• with a keratinous beak and no teeth
• descendants of dinosaurs