1. Name 3 Characteristics of Amphibians (5 Total)

SI 9/4 Lecture 4 Amphibians

1. Name 3 characteristics of Amphibians (5 total) a. Terrestrial, aquatic, or both b. Legless and/or gilled larval stage c. Smooth, permeable skin d. Egg without shell e. Generally oviparous with external fertilization

2. What theories discuss the reason amphibians moved to land (3 theories)? a. Predation hypothesis b. Food hypothesis c. Competitive avoidance hypothesis

3. Amphibian means…? a. Two lives

4. What are the three extant orders of amphibians? a. Gymnophiona - caecilians b. Caudata - Salamanders c. Anura - frogs/toads

5. What is known as the age of Amphibians? Carboniferous

6. During what age did Amphibians develop? a. Devonian

7. What ecological conditions were present during the Devonian that led to amphibians moving to land? a. Shallow seas – lots of contact with land b. Conditions moving from wet to drier c. Food found on land – plants and inverts abundant d. Land-sea contact – often in Tropical areas, minimizing need for temperature control e. Predators in ocean abundant (Devonian = age of fishes)

8. Name 4 problems associated with living on land a. Gravity b. Locomotion c. Breathing d. Feeding e. Reproduction f. Outer Covering g. Sensory systems

9. ______(Lungfish) are the closest living (fish) relative of tetrapods belong to class ______(Sarcopterygii)

10. What is a double breather? a. had both gills and open air passageways: external nares b. Internal nares (choanae) opening at back of nose connecting nasal passage to throat and lungs c. Osteolopiforms: Transitional Fish

11. Name 3 characteristics of transitional fish. a. Cylindrical-bodied, large-headed fishes b. Shallow water predators c. Were double breathers (had both gills and open air passageways: external nares) d. Internal nares (choanae) opening at back of nose connecting nasal passage to throat and lungs e. Well-ossified skeleton, jaws similar to those of tetrapods f. Locomotion: fins and fin support suggest terrestrial locomotion possible (and likely gave rise to terrestrial limbs) g. Primitive pectoral girdle between fins and vertebral column h. Lobelike fins supported by bones at their base

12. Name Several characteristics of Ichthyostega, which is a ______(stem) tetrapod. a. 1st good fossil of land vertebrate b. Small ~ 6 inches long c. Vertebrae fishlike (no interlocking connections) d. Tail long and fishlike, with fin rays e. Pectoral and pelvic girdles strong f. Polydactyly (7 toes)

13. ______and ______are examples of stem tetrapods. a. Acanthostega and Ichthyostega

14. ______likely gave rise to Lissamphibia a. Temnospondyls

15. What is Tiktaalik? • Amphibian ‘Missing Link’ • transitional fossil with mixed features • Fish features: bony scales, fin rays, fish tail, gill arches, fish-like jaw • Tetrapod features: shortened skull, modified ear, mobile neck, functional wrist, robust pectoral fins, no operculum (gill cover) • Importantly, FINS WITH WRISTS!!!

16. Why was Tiktaalik’s discovery so interesting to science? a. Scientists PREDICTED location for transitional amphibians (NW Canada)

17. Name 3 characteristics of Lissamphibia a. Loss of bone in skull (e.g., salamanders replace some bones with cartilage) b. Loss of scales (only 1 group retains) c. Most with 4 digits (not 5) d. 2 middle ear bones e. Weak teeth f. 3 chambered heart

18. True / False All Amphibians have a metamorphic life cycle. a. False

19. Name 3 characteristics of the order Gymnophiona a. Tropical b. Burrow underground or in leaf litter c. Legless and tailless d. Retain a few scales in neck e. Poorly studied

20. Name 3 characteristics of the order Caudata a. Eastern U.S. highest diversity on earth b. Generally have legs c. Show great deal of bone loss d. Can be long-lived (20 years) e. Most do not metamorphose

21. Name 3 characteristics of the order Anura a. Live in tropical, temperate, sub-arctic (and even desert) b. Large hind legs for leaping c. Metamorphic life cycle d. No tails as adults

22. A current ecological issue is the disappearance of ______(frogs)

23. True / False Amphibians are indicator species a. True

24. True / False Amphibians solved the problem of reproduction on land. a. False