IB-202-7 5-29-06

1. IB-202-75-29-06 The Amniotes

2. Amniotes also have other terrestrial adaptations • Such as relatively impermeable skin and the ability to use the rib cage to ventilate the lungs • Amphibians pump up their lungs by “gulping” air. Also much gas exchange through the moist skin

3. Early Amniotes • Early amniotes • Appeared in the Carboniferous period • Included large herbivores and predators

4. dinosaurs other Saurischian than birds Ornithischiandinosaurs Crocodilians Ichthyosaurs Plesiosaurs Squamates Mammals Pterosaurs Parareptiles Tuatara Turtles Birds Saurischians Dinosaurs Lepidosaurs Archosaurs Synapsids Diapsids Reptiles Ancestralamniote Figure 34.23 Diapsid referrs to two holes in the skull. Synapsid referrs to a single hole in the skull (would be the lower jaw fits into the zygomatic arch and the jaw muscle attaches to the temporal region of the skull • A phylogeny of amniotes

5. Reptiles • The reptile clade includes • The tuatara, lizards, snakes, turtles, crocodilians, birds, and the extinct dinosaurs

6. Figure 34.25 • Reptiles (including birds) • Have scales that create a waterproof barrier • Lay shelled eggs on land

7. Metabolic rate and body temperature • Most reptiles are ectothermic (cold blooded) • Absorbing external heat as the main source of body heat because they generate little heat with their low metabolism • Birds and mammals are endothermic • Capable of keeping the body warm through metabolism by conserving heat—if too warm they have mechanisms for losing heat

8. The Origin and Evolutionary Radiation of Reptiles • The oldest reptilian fossils • Date to about 300 million years ago • The first major group of reptiles to emerge • Were the parareptiles, which were mostly large, stocky herbivores (extinct)

9. dinosaurs other Saurischian than birds Ornithischiandinosaurs Crocodilians Ichthyosaurs Plesiosaurs Squamates Mammals Pterosaurs Parareptiles Tuatara Turtles Birds Saurischians Dinosaurs Lepidosaurs Archosaurs Synapsids Diapsids Reptiles Ancestralamniote Figure 34.23 • A phylogengy of amniotes The diapsids are composed of two main lineages As parareptiles were dwindling the diapsids were diversifying and give rise to two linages the lepidosaurs and the archosaurs

10. The dinosaurs • Diversified into a vast range of shapes and sizes • Included the long-necked giants called the theropods

11. Figure 34.26 • Traditionally, dinosaurs were considered slow, sluggish creatures • But fossil discoveries and research have led to the conclusion that dinosaurs were agile and fast moving • Paleontologists have also discovered signs of parental care among dinosaurs

12. (a) Tuatara (Sphenodon punctatus) Figure 34.27a Lepidosaurs • One surviving lineage of lepidosaurs • Is represented by a species of lizard-like reptile called tuatara (differs from other lizards in that it has the unmodified diapsid skull-two disticnt holes)

13. Figure 34.27b (b) Australian thorny devil lizard (Moloch horridus) • The other major living lineage of lepidosaurs • Are the squamates, the lizards and snakes • Lizards • Are the most numerous and diverse reptiles, apart from birds. Three chamber heart (amphibians 2 chambered heart)

14. (c) Wagler’s pit viper (Tropidolaemus wagleri), a snake Figure 34.27c • Snakes are legless lepidosaurs • That evolved from lizards and some even retain vestigial pelvic and limb bones indicating that their ancestors had legs

15. Figure 34.27d (d) Eastern box turtle (Terrapene carolina carolina) • All turtles have a boxlike shell • Made of upper and lower shields that are fused to the vertebrae, clavicles, and ribs • Turtles have adapted to deserts, ponds, rivers and the oceans

16. Figure 34.27e (e) American alligator (Alligator mississipiensis) Alligators and Crocodiles • Crocodilians • Belong to an archosaur lineage that dates back to the late Triassic. Live in warm environments. Lay egg in nests that they guard. Parental care.

17. Birds • Birds are archosaurs (7000 species) • But almost every feature of their reptilian anatomy has undergone modification in their adaptation to flight • Many of the characters of birds • Are adaptations that facilitate flight

18. Finger 1 (b) Bone structure Palm (a) wing Finger 2 Forearm Wrist Finger 3 Shaft Vane Barb Shaft Barbule Hook Figure 34.28a–c (c) Feather structure • A bird’s most obvious adaptations for flight • Are its wings and feathers No teeth Only 1 ovary/testis No urinary bladder Light weight skull One way air flow in lungs

19. The Origin of Birds • Birds probably descended from theropods • A group of small, carnivorous dinosaurs that had feathers, but not capable of fight

20. Wing claw Toothed beak Airfoil wing with contour feathers Long tail with many vertebrae Figure 34.29 Transitional form (Dino to bird) • By 150 million years ago • Feathered theropods had evolved into birds • Archaeopteryx • Remains the oldest bird known Teeth Wing claw Long tail with vertebrae Later forms show progressive loss of these characters.

21. (a) Emu. This ratite lives in Australia. Figure 34.30a Living Birds • The ratites, order Struthioniformes • Are all flightless. Lack “big” pectoral muscle and sternum keel.

22. (b) Mallards. Like many bird species, the mallard exhibits pronounced color differences between the sexes. (c) Laysan albatrosses. Like most birds, Laysan albatrosses have specific mating behaviors, such as this courtship ritual. (d) Barn swallows. The barn swallow is a member of the order Passeriformes. Species in this order are called perching birds because the toes of their feet can lock around a branch or wire, enabling the bird to rest in place for long periods. Figure 34.30b–d • The demands of flight • Have rendered the general body form of many flying birds similar to one another

23. Raptor(such as a bald eagle) Grasping bird (such as a woodpecker) Swimming bird(such as a duck) Perching bird (such as a cardinal) Figure 34.31 Structure Function • Foot structure in bird feet • Shows considerable variation

24. Feeding Adaptations • Both the feet and beaks of birds show structures best suited for their life style. • With regards to beaks some adapted for tearing like a hawk’s beak, flamingos filter plankton out of the water, woodpecker for pecking holes in rotten trees and extracting insects, seed eaters and New Zealand kee wee with a long beak for probing into soft ground for worms.

25. Mammals • Mammals are amniotes that have hair and produce milk • Mammals, class Mammalia • Are represented by more than 5,000 species. Most are placental mammals.

26. Derived Characters of Mammals • Mammary glands, which produce milk • Are a distinctively mammalian character • Hair is another mammalian characteristic • Mammals generally have a larger brain than other vertebrates of equivalent size • Endotherms with a closed 4 chambered heart • Ventilate lungs with a diaphragm • In contrast to the conical teeth of reptiles mammals have specialized teeth. Grinding molars for grass eaters, carnivores have stabbing canines, shearing premolars and molars for crushing bone. Teeth specialized for diet. • Example of specialized dentition in fish and seals.

27. Early Evolution of Mammals • Mammals evolved from synapsids in the late Triassic period but were small and remained insignificant because most of the ecological niches were filled by the dinosaurs of various sizes and forms. Mammals at that time were probably nocturnal (night forms), hid in burrows and fed on insects. After the dinosaurs died off at cretaceous tertiary boundary (maybe mostly due to the impact of a large asteroid) then there was an adaptive radiation of the mammals and they then filled the niches formerly occupied by the dinosaurs.

28. Jaw joint Jaw joint Dimetrodon Morganucodon Key Dentary Angular Squamosal Eardrum Middle ear Inner ear Articular Quadrate Inner ear Eardrum Stapes (a) The lower jaw of Dimetrodon is composed of several fused bones; two small bones, the quadrate and articular, form part of the jaw joint. In Morganucodon, the lower jaw is reduced to a single bone, the dentary, and the location of the jaw joint has shifted. Middle ear Stapes Incus (evolvedfrom quadrate) Sound Sound Malleus (evolvedfrom articular) Morganucodon Dimetrodon (b) During the evolutionary remodeling of the mammalian skull, the quadrate and articular bones became incorporated into the middle ear as two of the three bones that transmit sound from the eardrum to the inner ear. The steps in this evolutionary remodeling are evident in a succession of fossils. Figure 34.32a, b Evolution of the mammal ear • The jaw was remodeled during the evolution of mammals from nonmammalian synapsids • And two of the bones that formerly made of the jaw joint were incorporated into the mammalian middle ear

29. Three linages of mammals evolved • Monotremes- egg layers (3 species) • Marsupials– pouched mammals having a limited embryological development during the short gestation period in uterus. They finish development in a pouch obtaining nutrient from a milk nipple. • Placental mammals- development takes place only in the urterus

30. Figure 34.33 Monotremes • Monotremes • Are a small group of egg-laying mammals consisting of echidnas and the platypus Found only in Australia and New Guinea Have hair, produce milk but no nipples. Duck billed platypus (odd looking creature)

31. Marsupials • Marsupials • Include opossums, kangaroos, and koalas

32. A young brushtail possum. The young of marsupials are born very early in their development. They finish their growth while nursing from a nipple (in their mother’s pouch in most species). Figure 34.34a Australian Marsupials • A marsupial is born very early in its development • And completes its embryonic development while nursing within a maternal pouch called a marsupium Hind limbs are just buds. Mother fertilized after giving birth (33 days) and carries a fertilized egg in the uterus that does not develop unless she looses the juvenile in her pouch.

33. (b) Long-nosed bandicoot. Most bandicoots are diggers and burrowers that eat mainly insects but also some small vertebrates andplant material. Their rear-opening pouch helps protect the young from dirt as the mother digs. Other marsupials, such as kangaroos, have a pouch that opens to the front. Figure 34.34b • In some species of marsupials, such as the bandicoot • The marsupium opens to the rear of the mother’s body as opposed to the front, as in other marsupials

34. Marsupial mammals Eutherian mammals Plantigale Deer mouse Mole Marsupial mole Sugar glider Flying squirrel Wombat Woodchuck Wolverine Tasmanian devil Patagonian cavy Kangaroo Figure 34.35 • In Australia, convergent evolution • Has resulted in a diversity of marsupials that resemble eutherians in other parts of the world Although marsupials originated in the americas, only a few remain. The reason is they have been out-competed by the placental mammals. Why are marsupials so abundant in Australia? Because no placental mammals and the reason for that is the land masses separated before the placentals could reach Australia. Thus no natural placental mammals in Australia. Many marsupials threatened to day. Cane toad introduced to eat insects in sugar cane fields now eaten by some cat sized marsupials. Problem is there are poisonous secretions on the back of the cane toad and it kills the marsupial. Law against toad licking. Tasmanian tiger.

35. Eutherians (Placental Mammals) • Compared to marsupials • Eutherians have a longer period of pregnancy • Young eutherians • Complete their embryonic development within a uterus, joined to the mother by the placenta

36. This clade of eutherians evolved in Africa when the continent was isolated from other landmasses. It includesEarth’s largest living land animal (the African elephant), as well as species that weighless than 10 g. This diverse clade includes terrestrial and marine mammals as well as bats,the only flying mammals. A growingbody of evidence, including Eocene fossils of whales with feet,supports putting whales inthe same order (Cetartiodactyla) as pigs, cows, and hippos. All members of this clade, which underwent an adaptive radiation in South America, belong to the order Xenarthra. One species, the nine-banded armadillo, is found in the southern United States. This is the largest eutherian clade. It includes the rodents, which make up the largest mammalian order by far, with about 1,770 species. Humansbelong to the order Primates. Proboscidea Sirenia Tubulidentata Hyracoidea Afrosoricida (golden moles and tenrecs) Macroscelidea (elephant shrews) Rodentia Lagomorpha Primates Dermoptera (flying lemurs) Scandentia (tree shrews) Carnivora Cetartiodactyla Perissodactyla Chiroptera Eulipotyphla Pholidota (pangolins) Monotremata Marsupialia Xenarthra Monotremes Marsupials Eutherians Possible phylogenetic tree of mammals.All 20 extant orders of mammals are listed at the top of the tree. Boldfaced orders are explored on the facing page. Ancestral mammal Figure 34.36 • Phylogenetic relationships of mammals

37. MAIN CHARACTERISTICS ORDERS AND EXAMPLES ORDERS AND EXAMPLES MAIN CHARACTERISTICS Embryo completes development in pouch on mother Marsupialia Kangaroos, opossums, koalas Lay eggs; nonipples; young suck milk fromfur of mother MonotremataPlatypuses, echidnas Echidna Koala Tubulidentata Aardvark Teeth consisting of many thin tubes cemented together; eats ants and termites ProboscideaElephants Long, musculartrunk; thick, loose skin; upper incisors elongated as tusks African elephant Aardvark Hyracoidea Hyraxes Short legs; stumpy tail; herbivorous; complex, multichambered stomach Aquatic; finlikeforelimbs and no hind limbs; herbivorous SireniaManatees,dugongs Rock hyrax Manatee Chisel-like, continuously growing incisors worn down by gnawing;herbivorous Rodentia Squirrels, beavers, rats, porcupines, mice   XenarthraSloths, anteaters,armadillos Reduced teeth orno teeth; herbivorous(sloths) or carnivorous (anteaters, armadillos) Red squirrel Tamandua Primates Lemurs, monkeys, apes, humans Opposable thumbs; forward-facing eyes; well-developed cerebral cortex; omnivorous Lagomorpha Rabbits, hares, picas Chisel-like incisors; hind legs longer than forelegs and adapted for running and jumping Golden lion tamarin Jackrabbit Perissodactyla Horses, zebras, tapirs, rhinoceroses Hooves with an odd number of toeson each foot; herbivorous Sharp, pointed canineteeth and molars for shearing; carnivorous CarnivoraDogs, wolves,bears, cats, weasels, otters, seals, walruses Indian rhinoceros Coyote Chiroptera Bats Adapted for flight; broad skinfold that extends from elongated fingers to body and legs; carnivorous or herbivorous Hooves with an even number of toes on each foot; herbivorous CetartiodactylaArtiodactylsSheep, pigs cattle, deer,giraffes Frog-eating bat Bighorn sheep Aquatic; streamlinedbody; paddle-like forelimbs and no hind limbs; thicklayer of insulating blubber; carnivorous Eulipotyphla “Core insecti- vores”: some moles, some shrews Diet consists mainly of insects and other small invertebrates CetaceansWhales,dolphins,porpoises Star-nosed mole Pacific white-sided porpoise Figure 34.36 • The major eutherian orders

38. Primates • The mammalian order Primates include • Lemurs, tarsiers, monkeys, and apes • Humans are members of the ape group

39. Derived Characters of Primates • Most primates • Have hands and feet adapted for grasping • Primates also have • A large brain and short jaws • Forward looking eyes close together on the face, providing depth perception (binocular vision) • Well developed parental care and complex social behavior • A fully opposable thumb

40. The other two groups are • The tarsiers of Southeast Asia • The anthropoids, which include monkeys and hominids worldwide

41. Anthropoids 0 Chim-panzees Gorillas Tarsiers Gibbons Humans Orangutans Old World monkeys New World monkeys Lemurs, lorises, and pottos 10 20 Millions of years ago 30 40 50 Ancestral primate 60 Figure 34.38 • There are three main groups of living primates • The lemurs of Madagascar and the lorises and pottos of tropical Africa and southern Asia (many endangered because of deforestation) • The tarsiers of Southeast Asia • The anthropoids, which include monkeys and hominids worldwide • The oldest known anthropoid fossils, about 45 million years old • Indicate that tarsiers are more closely related to anthropoids than lemurs

42. Figure 34.37 Living Primates • A lemur from Madagascar (many endangered because of deforestation)

43. Evolution of Monkeys • The first monkeys • Evolved in the Old World (Africa and Asia) • The fossil record indicates that monkeys first appeared in the New World (South America) during the Oligocene (30 mya) after the separation of Africa from S. America. Thought that they may have been rafted over from Africa on logs. Monkeys on both continents underwent separate adaptive radiations and are quite different.

44. (a) New World monkeys, such as spider monkeys (shown here), squirrel monkeys, and capuchins, have a prehensile tail and nostrils that open to the sides. (b) Old World monkeys lack a prehensile tail, and their nostrils open downward. This group includes macaques (shown here), mandrills, baboons, and rhesus monkeys. Figure 34.39a, b • New World and Old World monkeys • Underwent separate adaptive radiations during their many millions of years of separation Both aboreal and ground-dwelling. Social. Aboreal, social diurnal.

45. (a) Gibbons, such as this Muller's gibbon, are found only in southeastern Asia. Their very long arms and fingers are adaptations for brachiation. (b) Orangutans are shy, solitary apes that live in the rain forests of Sumatra and Borneo. They spend most of their time in trees; note the foot adapted for grasping and the opposable thumb. (c) Gorillas are the largest apes: some males are almost 2 m tall and weigh about 200 kg. Found only in Africa, these herbivores usually live in groups of up to about 20 individuals. (e) Bonobos are closely related to chimpanzees but are smaller. They survive today only in the African nation of Congo. (d) Chimpanzees live in tropical Africa. They feed and sleep in trees but also spend a great deal of time on the ground. Chimpanzees are intelligent, communicative, and social. Figure 34.40a–e • The other group of anthropoids, the hominoids diverged from monkeys 25 mya • Consists of primates informally called apes

46. The Earliest Humans • Hominoids diverged from Old World monkeys about 20–25 million years ago • Humans are bipedal hominoids with a large brain • Homo sapiens is about 160,000 years old • Which is very young considering that life has existed on Earth for at least 3.5 billion years

47. Important mile stones in vertebrate evolution • Appearance of a vertebral column for support (early fish) • Head, skull and associated sensory organs • Jaws for feeding specialization • Appendages (fins and limbs) • Transition from water to land, but reproduction still tied to the aquatic environment • Amniotic egg allowed for reproduction in dry environments. • Adaptative radiations in fish and mammals with tooth specialization

48. Friday (Chapt 40,all)Basic principles of animal form and function • Next week chpt 41 all, animal nutrition