1. The Chordata Chapter 34

2. The Chordata I Chapter 34 1.General features and earliest groups 2.The neural crest and the origin of the craniates 3.With Gnathostomes come jaws and two pairs of appendages 4.Lateral Lines, Lungs, and Swim Bladders 5.Origin of Tetrapods, Amphibians 6.The Amniotic Egg and the Dinosaur Pelvis

3. Figure 34.2 Chordate characteristics

4. Figure 34.4b Subphylum Cephalochordata: the lancelet Branchiostoma

5. Figure 34.4a Subphylum Cephalochordata: lancelet anatomy

6. Pikaia, the Burgess-shale chordate, with evident somites

7. Primitive chordates suggest first steps in their evolution ---

8. The Chordata I Chapter 34 1.General features and earliest groups 2.The neural crest and the origin of the craniates 3.With Gnathostomes come jaws and two pairs of appendages 4.Lateral Lines, Lungs, and Swim Bladders 5.Origin of Tetrapods, Amphibians 6.The Amniotic Egg and the Dinosaur Pelvis

9. Figure 34.1 Clades of extant chordates

11. Figure 34.9 A hagfish A skull of cartilage, but no jaw, no vertebrae

12. The Chordata I Chapter 34 1.General features and earliest groups 2.The neural crest and the origin of the craniates 3.With Gnathostomes come jaws and two pairs of appendages 4.Lateral Lines, Lungs, and Swim Bladders 5.Origin of Tetrapods, Amphibians 6.The Amniotic Egg and the Dinosaur Pelvis

13. Figure 34.7 Phylogeny of the major groups of extant vertebrates

14. Figure 34.11 Cartilaginous fishes (class Chondrichthyes): Great white shark (top left), silky shark (top right), southern stingray (bottom left), blue spotted stingray (bottom right)

15. lateral line – first in sharks and rays, homologous to the hair-cell array in the cochlea

16. Figure 34.12a Ray-finned fishes (class Actinopterygii): yellow perch

17. Figure 34.12b Ray-finned fishes (class Actinopterygii): long-snouted sea horse

18. Figure 34.13 Anatomy of a trout, a representative ray-finned fish

19. Figure 34.7 Phylogeny of the major groups of extant vertebrates

20. Figure 34.18 A coelocanth (Latimeria), the only extant lobe-finned genus

21. The Chordata I Chapter 34 1.General features and earliest groups 2.The neural crest and the origin of the craniates 3.With Gnathostomes come jaws and two pairs of appendages 4.Lateral Lines, Lungs, and Swim Bladders 5.Origin of Tetrapods, Amphibians 6.The Amniotic Egg and the Dinosaur Pelvis

22. Figure 34.15 The origin of tetrapods

23. Figure 34.16 Skeleton of Acanthostega, a Devonian tetrapod fish Transitional tetrapods -- feet in place but gills and tail with fin

24. Figure 34.17 Amphibian orders: Newt (left), frog (right)

25. Figure 34.18 “Dual life” of a frog (Rana temporaria)

26. The Chordata I Chapter 34 1.General features and earliest groups 2.The neural crest and the origin of the craniates 3.With Gnathostomes come jaws and two pairs of appendages 4.Lateral Lines, Lungs, and Swim Bladders 5.Origin of Tetrapods, Amphibians 6.The Amniotic Egg and the Dinosaur Pelvis

27. Figure 34.22 A hatching reptile

28. Figure 34.24 Amniotic egg Amnion: cushioning chamber for embryo Chorion: gas exchange to exterior Allantois: disposal sac