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9 Animal Phyla + Plant Slides Invertebrates copyright cmassengale 2 Invertebrate Phyla • • • • • • • • Porifera Cnidarians Platyhelminthes Nematodes Mollusks Annelids Echinoderms Arthropods 4 Sponges (Porifera) • Most primitive • Cells relatively independent • Mostly marine • No Symmetry 5 Cnidarians • Mostly marine • Radial Symmetry 6 Cnidarians • Jellyfish • Hydra • Coral •Sea anemone •Portuguese Man-O-War 7 Platyhelminthes • Flatworms • Bilateral symmetry • Cephalization 8 Planarian – freshwater flatworm 9 Nematodes • Tube-like digestive tract • Roundworms! • Mouth and anus • No segmentation 10 Mollusks • Clams, snails, squids • Varied habitats – Marine – Freshwater – Terrestrial 11 Annelids • Segmented worms • Common earthworm • Leech 12 Arthropods • Joint-legged animals • External skeleton • Huge variation – mostly insects 13 Echinoderms copyright cmassengale Echinodermata means “spiny skin” Echinoderms usually inhabit shallow coastal waters and ocean trenches organisms in this class include: • • • • Sea stars Brittle stars Sand dollars Sea cucumbers copyright cmassengale change from a free-swimming bilaterally symmetrical larva to a bottom-dwelling adult with radial symmetry. Most have five radii or multiples which is known as pentaradial symmetry they have an endoskeleton that is made up of calcium plates, may include protruding spines copyright cmassengale Have small feet called tube feet that aid in movement, feeding, respiration, & excretion. Do not have circulatory, respiratory of excretory systems. Have a nervous system but no head or brain. There are two sexes and they can produce sexually and asexually. copyright cmassengale hydrostatic pressure permits movement Path of water in the Water-Vascular System enters sieve plate passes through stone canal traces a path from the ring canal encircling mouth to 5 radial canals that extend to each arm copyright cmassengale ampulla: bulblike sac that each foot connects to feet contract, water enters and are able to suction onto surface of slippery rocks copyright cmassengale uses feet eat mollusks, worms, and slow-moving animals enzymes help digest food copyright cmassengale fluid in coelom bathes organs & distributes nutrients & oxygen skin gills: protect coelom lining; gases are exchanged nerve ring: surrounds mouth & branches off into nerve cords in each arm. Eyespots: on each arm that responds to light tentacles: responds to touch copyright cmassengale copyright cmassengale Echinoderms • Always marine • Starfishes, sea urchins, sea lilies • Spiny skin 23 Brittle Star – An Echinoderm 24 Chapter 34 Vertebrates • Overview: Half a Billion Years of Backbones • By the end of the Cambrian period, some 540 million years ago – An astonishing variety of animals inhabited Earth’s oceans • One of these types of animals – Gave rise to vertebrates, one of the most successful groups of animals • The animals called vertebrates – Get their name from vertebrae, the series of bones that make up the backbone Figure 34.1 • There are approximately 52,000 species of vertebrates – Which include the largest organisms ever to live on the Earth • What is a deuterostome? • What is a protostome? Tomorrow • Exit quiz on 9 phla • Concept 34.1: Chordates have a notochord and a dorsal, hollow nerve cord • Vertebrates are a subphylum of the phylum Chordata • Chordates are bilaterian animals – That belong to the clade of animals known as Deuterostomia • Two groups of invertebrate deuterostomes, the urochordates and cephalochordates – Are more closely related to vertebrates than to invertebrates Derived Characters of Chordates • All chordates share a set of derived characters – Although some species possess some of these traits only during embryonic development Dorsal, Muscle segments Notocho rd hollow nerve cord Brain Mouth Anus Figure 34.3 Muscular, post-anal tail Pharyngeal slits or clefts • Notochord The notochord – Is a longitudinal, flexible rod located between the digestive tube and the nerve cord – Provides skeletal support throughout most of the length of a chordate • In most vertebrates, a more complex, jointed skeleton develops – And the adult retains only remnants of the embryonic notochord Dorsal, Hollow Nerve Cord • The nerve cord of a chordate embryo – Develops from a plate of ectoderm that rolls into a tube dorsal to the notochord – Develops into the central nervous system: the brain and the spinal cord • Pharyngeal Slits or Clefts In most chordates, grooves in the pharynx called pharyngeal clefts – Develop into slits that open to the outside of the body • These pharyngeal slits – Function as suspension-feeding structures in many invertebrate chordates – Are modified for gas exchange in aquatic vertebrates – Develop into parts of the ear, head, and neck in terrestrial vertebrates • Muscular, Post-Anal Tail Chordates have a tail extending posterior to the anus – Although in many species it is lost during embryonic development • The chordate tail contains skeletal elements and muscles – And it provides much of the propelling force in many aquatic species • Concept 34.2: Craniates are chordates that have a head • The origin of a head – Opened up a completely new way of feeding for chordates: active predation • Craniates share some common characteristics – A skull, brain, eyes, and other sensory organs • A phylogeny of amniotes Saurischians Dinosaurs Lepidosaurs Archosaurs Synapsids Diapsids Reptiles Ancestral amniote Figure 34.23 Derived Characters of Amniotes • Amniotes are named for the major derived character of the clade, the amniotic egg – Which contains specialized membranes that protect the embryo • The extraembryonic membranes Extraembryonic membranes – Have various functions Allantois. The allantois is a disposal sac for certain metabolic wastes produced by the embryo. The membrane of the allantois also functions with the chorion as a respiratory organ. Amnion. The amnion protects the embryo in a fluid-filled cavity that cushions against mechanical shock. Chorion. The chorion and the membrane of the allantois exchange gases between the embryo and the air. Oxygen and carbon dioxide diffuse freely across the shell. Yolk sac. The yolk sac contains the yolk, a stockpile of nutrients. Blood vessels in the yolk sac membrane transport nutrients from the yolk into the embryo. Other nutrients are stored in the albumen (“egg white”). Embryo Amniotic cavity with amniotic fluid Yolk (nutrients) Albumen Shell Figure 34.24 • Amniotes also have other terrestrial adaptations – Such as relatively impermeable skin and the ability to use the rib cage to ventilate the lungs Early Amniotes • Early amniotes – Appeared in the Carboniferous period – Included large herbivores and predators Reptiles • The reptile clade includes – The tuatara, lizards, snakes, turtles, crocodilians, birds, and the extinct dinosaurs • Reptiles – Have scales that create a waterproof barrier – Lay shelled eggs on land Figure 34.25 • Most reptiles are ectothermic – Absorbing external heat as the main source of body heat • Birds are endothermic – Capable of keeping the body warm through metabolism 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 Lepidosaurs • One surviving lineage of lepidosaurs – Is represented by two species of lizard-like reptiles called tuatara Figure 34.27a (a) Tuatara (Sphenodon punctatus) Birds • Birds are archosaurs – But almost every feature of their reptilian anatomy has undergone modification in their adaptation to flight Derived Characters of Birds • Many of the characters of birds – Are adaptations that facilitate flight • A bird’s most obvious adaptations for flight – Are its wings and feathers Finger 1 (b) Bone structure Palm (a) wing Finger 2 Forearm Wrist Vane Shaft Figure 34.28a–c Finger 3 Shaft Barb Barbule Hook (c) Feather structure Win Toothed beak • By 150 million years ago – Feathered theropods had evolved into birds • Archaeopteryx Airfoil wing with contour feathers Figureknown 34.29 – Remains the oldest bird Long tail with many vertebrae Living Birds • The ratites, order Struthioniformes – Are all flightless (a) Emu. This ratite lives in Australia. Figure 34.30a • Concept 34.7: Mammals are amniotes that have hair and produce milk • Mammals, class Mammalia – Are represented by more than 5,000 species 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 • 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 Jaw joint Key Jaw joint Dentary Angular Squamosal Articular Quadrate Dimetrodon Morganucodon (a) The lower jaw of Dimetrodon is composed of several fused bones; two small bones, the quad and articular, form part of the jaw joint. In Morganucodon, the lower jaw is reduced to a sin the dentary, and the location of the jaw joint has shifted. Middle ear Stapes Eardrum Inner ear Middle ear Inner ear Eardrum Stapes Sound Sound Incus (evolved from quadrate) Malleus (evolved from articular) Figure 34.32a, b Morganucodon Dimetrodon (b) During the evolutionary remodeling of the mammalian skull, the quadrate and articular bones b into the middle ear as two of the three bones that transmit sound from the eardrum to the inner this evolutionary remodeling are evident in a succession of fossils. Monotremes • Monotremes – Are a small group of egg-laying mammals consisting of echidnas and the platypus Figure 34.33 Marsupials • Marsupials – Include opossums, kangaroos, and koalas • A marsupial is born very early in its development – And completes its embryonic development (a) A young brushtail The young of whilepossum. nursing within a maternal pouch called a marsupials are born very early in their development. They finish their growth marsupium while nursing from a nipple (in their mother’s pouch in most species). Figure 34.34a • 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 (b) Long-nosed bandicoot. Most bandicoots are diggers and burrowers that eat mainly other marsupials insects but also some small vertebrates and plant 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 Australia, convergent evolution – Has resulted in a diversity of marsupials that resemble eutherians in other parts of the world Marsupial mammals Plantigale Marsupial mole Eutherian mammals Deer mouse Mole Sugar glider Flying squirrel Wombat Woodchuck Tasmanian devil Kangaroo Figure 34.35 Wolverine Patagonian cavy 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 This clade of eutherians evolved in Africa when the continent was isolated from other landmasses. It includes Earth’s largest living land animal (the African elephant), as well as species that weigh less than 10 g. 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. Humans belong to the order Primates. This diverse clade includes terrestrial and marine mammals as well as bats, the only flying mammals. A growing body of evidence, including Eocene fossils of whales with feet, supports putting whales in the same order (Cetartiodactyla) as pigs, cows, and hippos. • Phylogenetic relationships of mammals Monotremata Marsupialia Monotremes Marsupials Ancestral mammal Figure 34.36 Proboscidea Sirenia Tubulidentata Hyracoidea Afrosoricida (golden moles and tenrecs) Macroscelidea (elephant shrews) Xenarthra Rodentia Lagomorpha Primates Dermoptera (flying lemurs) Scandentia (tree shrews) Carnivora Cetartiodactyla Perissodactyla Chiroptera Eulipotyphla Pholidota (pangolins) 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. MAIN CHARACTERISTICS ORDERS AND EXAMPLES Lay eggs; no nipples; young suck milk from fur of mother Monotremata Platypuses, echidnas ORDERS AND EXAMPLES Echidna Proboscidea Elephants Long, muscular trunk; thick, loose skin; upper incisors elongated as tusks Koala Tubulidentata Aardvark African elephant Teeth consisting of many thin tubes cemented together; eats ants and termites Aardvark Aquatic; finlike forelimbs and no hind limbs; herbivorous Sirenia Manatees, dugongs Embryo completes development in pouch on mother Marsupialia Kangaroos, opossums, koalas • The major eutherian orders MAIN CHARACTERISTICS Hyracoidea Hyraxes Rock hyrax Short legs; stumpy tail; herbivorous; complex, multichambered stomach Manatee Xenarthra Sloths, anteaters, armadillos Reduced teeth or no teeth; herbivorous (sloths) or carnivorous (anteaters, armadillos) Rodentia Squirrels, beavers, rats, porcupines, mice Chisel-like, continuously growing incisors worn down by gnawing; herbivorous Red squirrel Tamandua Lagomorpha Rabbits, hares, picas Chisel-like incisors; hind legs longer than forelegs and adapted for running and jumping Primates Lemurs, monkeys, apes, humans Golden lion tamarin Jackrabbit Carnivora Dogs, wolves, bears, cats, weasels, otters, seals, walruses Sharp, pointed canine teeth and molars for shearing; carnivorous Perissodactyla Horses, zebras, tapirs, rhinoceroses Hooves with an even number of toes on each foot; herbivorous Chiroptera Bats Frog-eating bat Bighorn sheep Cetaceans Whales, dolphins, porpoises Figure 34.36 Pacific whitesided porpoise Hooves with an odd number of toes on each foot; herbivorous Indian rhinoceros Coyote Cetartiodactyla Artiodactyls Sheep, pigs cattle, deer, giraffes Opposable thumbs; forward-facing eyes; well-developed cerebral cortex; omnivorous Aquatic; streamlined body; paddle-like forelimbs and no hind limbs; thick layer of insulating blubber; carnivorous Eulipotyphla “Core insectivores”: some moles, some shrews Adapted for flight; broad skinfold that extends from elongated fingers to body and legs; carnivorous or herbivorous Diet consists mainly of insects and other small invertebrates Star-nosed mole Primates • The mammalian order Primates include – Lemurs, tarsiers, monkeys, and apes • Humans are members of the ape group 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 – Well-developed parental care and complex social behavior – A fully opposable thumb
