l. Chordata subphyla: Urochordata Cephalochordata Vertebrata

1. l. Chordata subphyla: Urochordata Cephalochordata Vertebrata

2. Patterns in evolution: Innovation, radiation, competitive contraction

3. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata “Jawless fishes” Lampreys and Hagfish Lamprey larvae look very much like cephalochordates

4. 5. Major Phyla Deuterostomes: I. Chordata Vertebrata “Jawless fishes” Evolve in late Cambrian, radiate in the Ordovician

5. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes – Jawed Vertebrates Move from detritivores to predators

6. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes – Jawed Vertebrates The Devonian was the “Age of Fishes” – a radiation of the first jawed vertebrates, dominated first by the Placoderms and then by Cartilaginous and bony fishes Arthrodires Placoderms Antiarchs Chondrichthyes (Sharks, rays) Acanthodians Teleosts Ray-finned Fishes Bony Fish Lobe-finned Fishes

7. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes – Jawed Vertebrates The Devonian was the “Age of Fishes” – a radiation of the first jawed vertebrates, dominated first by the Placoderms and then by cartilaginous and bony fishes

8. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes – Jawed Vertebrates Bony fishes dominate today: lighter skeleton and swim bladder Ray-finned Fishes Lobe-finned Fishes

9. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes – Jawed Vertebrates Bony Fishes (Osteichthyes) comprise 40% of living vertebrate species

10. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes - Tetrapods 350 mya Devonian 417 mya

11. Radiation of the “stem tetrapods” !!! Carboniferous Coastal swamps! Old friends a fish

12. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes - Tetrapods Caecilians Salamanders Frogs

14. Radiation of the “stem tetrapods” !!! Carboniferous Coastal swamps! Old friends a fish

15. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes The Permian Formation of Pangaea dries the landscape; amniotes dominate like the gymnosperms.

16. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes The amniotic egg was a big advance - amnion protects the embryo - yolk sac provides nourishment - allantoic sac holds waste produced by embryo Resist desiccation Provision embryo allows for colonization of dry habitats

17. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes SYNAPSID Amniote ancestor Hylonomus Casineria ANAPSID (turtles?) DIAPSID

18. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes Dimetrodon – a Pelycosaur Pelycosaurs The Permian The synapsids radiate and dominate Dicynodonts Gorgonopsids Therapsids Cynodonts Mammals A cynodont

19. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes Mammals - excellent transitional sequences from cynodont ‘reptiles’ - first fossils with all mammalian features (jaw, ear, dentition, fur) date to ~200 mya - Morganucodontids

20. Radiations of Mammals They diversify during the Mesozoic, but the modern groups radiate and dominate in the Cenozoic

21. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes Mammals - Monotremes: lay eggs, “sweat” milk

22. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes Mammals - Marsupials: live birth to embryo – attaches to nipple to complete development. Mother does not need to abandon the nest/young to feed. Pygmy possum – Australia (opossums in Western Hemisphere)

25. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes Mammals - Monotremes: egg laying, “sweat” milk - Marsupials: live birth to embryo – attaches to nipple to complete development. Mother does not need to abandon the nest/young to feed. - Placentals: Longer internal development allows for precocial behavior (independence on birth); placental allows for direct, energy-efficient transfer of nutrients between blood systems of mother and offspring. FOOD DIGESTION Each energy transformation is less than 100% efficient Nutrients in bloodstream of mother Milk production in mammary glands FOOD for OFFSPRING Placenta Nutrients in bloodstream of offspring DIGESTION

26. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes - Archosaurs Crocodilians Pterosaurs Ornithiscians Dinosaurs Sauropods Theropods Carnosaurs Saurischians Birds

28. Feathers: - ornamentation - endothermy (insulation) - lift (flight)

29. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes Birds: (derived traits) No teeth Feathers and endothermy flight feathers keeled breastbone Clavicles united into wishbone Pneumatic skeleton (houses air sacs from respiratory system) Unidirectional respiration

30. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes In the Mesozoic, the synapsids are replaced by the great diapsid radiations of Ichthyosaurs, Pterosaurs, and Dinosaurs Archosaurs: Dinosaurs, Pterosaurs, Crocodilians, Birds Lepidosaurs:Lizards, Snakes, Sphenodonts) Diapsida Ichthyosaurs Younginiformes

31. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes - Lepidosaurs Keuhniosaurs Squamates Scales, moveable quadrate (double hinged jaw), hinged skull Rhynchocephalians (Tuatara)

32. 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes - Lepidosaurs - Squamates