5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes - Tetrapods 350 mya 417 mya...
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Transcript of 5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes - Tetrapods 350 mya 417 mya...
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes
- Tetrapods350 mya
417 mya
Devonian
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes
- Tetrapods
Caecilians
Salamanders
Frogs
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
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes
Tetrapods - Amniotes
Amniote ancestor
Hylonomus
Casineria
ANAPSID (turtles?)
DIAPSID
SYNAPSID
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes
Tetrapods - Amniotes
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes
Tetrapods - Amniotes
The Permian
Formation of Pangaea dries the landscape; amniotes dominate like the gymnosperms.
shelled egg and the seed
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes
Tetrapods - Amniotes
The Permian
The synapsids radiate and dominate
Mammals
Cynodonts
Gorgonopsids
Therapsids
Pelycosaurs
Dicynodonts
Dimetrodon – a Pelycosaur
A cynodont
5. Major PhylaDeuterostomes: 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
Radiations of Mammals
They diversify during the Mesozoic, but the modern groups radiate and dominate in the Cenozoic
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes
Tetrapods - Amniotes
Mammals
- Monotremes: lay eggs, “sweat” milk
5. Major PhylaDeuterostomes: 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.
Pygmy possum – Australia(opossums in Western Hemisphere)
5. Major PhylaDeuterostomes: 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
Nutrients in bloodstream of mother
Milk production in mammary glands
FOOD for OFFSPRING
DIGESTION
Nutrients in bloodstream of offspring
Placenta
Each energy transformation is less than 100% efficient
5. Major PhylaDeuterostomes: 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 more direct and energy-efficient nutrient transfer
precocialaltricial
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes
Tetrapods - Amniotes
In the Mesozoic, the synapsids are replaced by the great diapsid radiations of Ichthyosaurs, Pterosaurs, and Dinosaurs
Diapsida
Younginiformes
Ichthyosaurs
Lepidosaurs: Lizards, Snakes, Sphenodonts)
Archosaurs: Dinosaurs, Pterosaurs, Crocodilians, Birds
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes
Tetrapods - Amniotes - Archosaurs
Crocodilians
Pterosaurs
Dinosaurs
Ornithiscians
Saurischians
Sauropods
Theropods Carnosaurs
Birds
5. Major PhylaDeuterostomes: 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
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes
Tetrapods - Amniotes
In the Mesozoic, the synapsids are replaced by the great diapsid radiations of Ichthyosaurs, Pterosaurs, and Dinosaurs
Diapsida
Younginiformes
Ichthyosaurs
Lepidosaurs: Lizards, Snakes, Sphenodonts)
Archosaurs: Dinosaurs, Pterosaurs, Crocodilians, Birds
Keuhniosaurs
Rhynchocephalians (Tuatara)
Squamates
Scales, moveable quadrate (double hinged jaw), hinged skull
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes
Tetrapods - Amniotes - Lepidosaurs