1. Chap 42 Amphibians

2. Amphibian Classification (with example) Kingdom = Animalia Phylum = Chordata Subphylum = Vertebrata Class = Amphibia Order = Caudata Family = Ambystomatidae Genus = Ambystoma Species = Ambystoma tigrinum http://fwie.fw.vt.edu/VHS/ Reference: Colbert, E.H. 2001. Colbert’s evolution of the vertebrates.Wiley-Liss

3. Kingdom Animalia Eukaryotes –Organelles, large cells No cell walls Specialized cell types http://www-class.unl.edu/bios201a/

4. Phylum Chordata Gill slits Dorsal nerve cord Notochord or vertebral column Amphioxus: a non-vertebrate chordate

5. Subphylum Vertebrata Vertebral column Skull (i.e., cranium) http://medic.med.uth.tmc.edu/Lecture/labeled/bs106001.gif http://face-and-emotion.com/dataface/physiognomy/media/cranium_side.jpg

6. Comparison of Vertebrate “Class” Traits (continued) Class RespirationBody temperature regulation Body covering Agnatha/Chondricthy es/ Osteichthyes GillsEctothermyScales AmphibiaGills, lungsEctothermySkin (smooth or warty) ReptiliaLungsEctothermyScales AvesLungsEndothermyFeathers, scales MammalsLungsEndothermyHair

7. http://www.cr.nps.gov/museum/exhibits/dino/geotime/ 1 st amphibians 1 st reptiles 1 st Homo sapiens

8. Evolutionary Relationships Amphibia Amniota Anapsida Diapsida Testudines (turtles) Mammalia Aves and other Dinosauria Squamata (snakes, lizards) Sphenodonta Crocodylia Synapsida Osteichthyes

9. 1 st Amphibians (Devonian Period; 408-360 mya) Eusthenopteron (a sarcopterygian fish) could be the ancestor of amphibians) http://www.lautringer.de/Alle_Dinosaurier_in_Kaiserslau/Dinosaurier_Album_1/ Krohne (2000)

10. 1 st Amphibians (Devonian Period; 408-360 mya) Acanthostega (a sarcopterygian fish) could be the ancestor of amphibians http://www.nhm.ac.uk/hosted_sites/paleonet/vop/glimpse/lab-m.jpg http://www5b.biglobe.ne.jp/~hilihili/keitou/mizika/sarcopterygii/sarco-gazou/acantho.jpg

11. Other Early Amphibians Eryops (2-m long predator; 360-320 mya) Forey (1988)http://www.geocities.co.jp/HeartLand-Suzuran/3621/ Diplocaulus (290-245 mya)

12. Modern Amphibians http://www.herpnet.net/Iowa-Herpetology/ http://fwie.fw.vt.edu/VHS/ http://www.herpnet.net/Iowa-Herpetology/ http://www.mybitoftheplanet.com/2002/ CaudataAnura

13. Modern Reptiles Order Testudines (turtles) Order Squamata (lizards, snakes) http://www.herpnet.net/Iowa-Herpetology/images/

14. 02 Feb. 2009Amphibians.ppt14 Class Amphibians Less well adapted to terrestrial environment –Smooth skin, no scales (no keratin ?) –External fertilization depend on water for mating; sperm and eggs released together into water –No embryonic membranes, –Egg must stay moist usually in water, rarely in moist soil

15. Anamniotic egg Jellylike (unshelled; must develop in water) Small-sized (lack large membranes to nourish embryo and store waste) Amphibian egg mass http://epod.usra.edu/archive/images/egg_mass.jpg

16. 02 Feb. 2009Amphibians.ppt16 Amphibian Life Cycle Live in two habitats –exploit two sets of resources Produce large numbers of eggs No parental care, tadpoles “on their own”

17. 02 Feb. 2009Amphibians.ppt17 Amphibian Life Cycle Advantages –Produce abundant offspring (less investment of matter, energy in each) –At least a few likely to survive. Disadvantages –Each egg/tadpole has small chance of survival wasteful –dependent on water, few can live far from surface water

18. 02 Feb. 2009Amphibians.ppt18 Class Amphibians Order Caecilians –Legless (apoda), burrowing (resemble earthworms, but with skull & backbone) –Tropical –blind

19. 02 Feb. 2009Amphibians.ppt19 Class Amphibians Order Urodela Order Salamanders (Urodela- tail visable) –Primitive form with four equal legs –Retain tail –Freshwater-Not found in Australia –Keep gills all life

20. Salamanders (Urodela) Mud puppies (East US) Axolotl Rocky Mountains

21. Compare Urodela to lizard

22. Some secrete poison or bad taste

23. Eastern American Hellbender reach 17-21 inches

24. Japanese Hellbender reach 29 inches to 5 feet

25. New Salamanders discovered in Costa Rica, January 2004 http://news.nationalgeographic.com/news/2008/01/ph otogalleries/salamander-pictures/photo4.html