The Animal Kingdom The Chordates
Phylum Hemichordata Hemichordata (hemi = half; chordata= cord) acorn worm entirely marine adults show 3 of 4 basic characteristics: 1) pharyngial pouches 2) dorsal tubular nerve chord 3) tail evolutionary link between echinoderm and chordates ciliated larvum resembles tornaria larvum of echinoderms
Phylum Chordata Subphylum Urochordata (uro = tail; chordata= cord) Subphylum Cephalochordata (cephalo = head; chordata= cord) Subphylum Vertebrata (vertebrate = backbone)
Phylum Chordata All exhibit four chordata characteristics: 1) dorsal tubular nerve cord 2) notochord 3) pharyngial pouches 4) tail Deutrostomes chordates & echinoderms
Anatomy of a Chordate
Subphylum Urochordata sea squirts or tunicates notochord present only in free-swimming larvum notochord does not extend into head larvum is free-swimming but non-feeding adult is sessile filter feeder
Subphylum Urochordata sea squirts or tunicate Campbell p 631 Settle after brief free-swimming larvum existence. Attaches at anterior end. Metamorphosis begins. Body turns 180 0. Tail, notochord, dorsal nerve cord, disappear.
Subphylum Cephalochordata head cord lancelet or Amphioxus notochord present throughout life extends into head region shallow marine waters chordate characteristics developed and apparent in adult tail has blocks of muscles called myotomes adults resemble tunicate larvum
Anatomy of a lancelet
Cephalochordata: lancelet
Subphylum Vertebrata General Characteristics: chordates with a backbone exhibit cephalization closed circulatory system neural crest (p. 633)
Subphylum Vertebrata Agnatha (without jaws) lamprey parasitic bloodsuckers w/ rasping tongue hagfish mainly scavengers no paired appendages larvum resembles lancelet
Agnatha: a sea lamprey
Lamprey mouth
Subphylum Vertebrata Chondrichthyes (cartilaginous fishes) flexible endoskeletons of cartilage strengthened by calcium granules sharks (internal fertilization) oviparous egg laying ovoviviparous retain fertilized eggs hatch within the uterus viviparous young develop in the uterus suspension-feeders (plankton)
Phylum Hemichordata Hemichordata (hemi = half; chordata= cord) acorn worm entirely marine adults show 3 of 4 basic characteristics: 1) pharyngial pouches 2) dorsal tubular nerve chord 3) tail evolutionary link between echinoderm and chordates ciliated larvum resembles tornaria larvum of echinoderms
Phylum Chordata Subphylum Urochordata (uro = tail; chordata= cord) Subphylum Cephalochordata (cephalo = head; chordata= cord) Subphylum Vertebrata (vertebrate = backbone)
Phylum Chordata All exhibit four chordata characteristics: 1) dorsal tubular nerve cord 2) notochord 3) pharyngial pouches 4) tail Deutrostomes chordates & echinoderms
Anatomy of a Chordate
Subphylum Urochordata sea squirts or tunicates notochord present only in free-swimming larvum notochord does not extend into head larvum is free-swimming but non-feeding adult is sessile filter feeder
Subphylum Urochordata sea squirts or tunicate Campbell p 631 Settle after brief free-swimming larvum existence. Attaches at anterior end. Metamorphosis begins. Body turns 180 0. Tail, notochord, dorsal nerve cord, disappear.
Subphylum Cephalochordata head cord lancelet or Amphioxus notochord present throughout life extends into head region shallow marine waters chordate characteristics developed and apparent in adult tail has blocks of muscles called myotomes adults resemble tunicate larvum
Anatomy of a lancelet
Cephalochordata: lancelet
Subphylum Vertebrata General Characteristics: chordates with a backbone exhibit cephalization closed circulatory system neural crest (p. 633)
Subphylum Vertebrata Agnatha (without jaws) lamprey parasitic bloodsuckers w/ rasping tongue hagfish mainly scavengers no paired appendages larvum resembles lancelet
Subphylum Vertebrata Chondrichthyes (cartilaginous fishes) flexible endoskeletons of cartilage strengthened by calcium granules sharks (internal fertilization) oviparous egg laying ovoviviparous retain fertilized eggs hatch within the uterus viviparous young develop in the uterus suspension-feeders (plankton)
Subphylum Vertebrata Chondrichthyes (cartilaginous fishes) Rays & skates Bottom feeders mollusks & crustaceans Whiplike tail w/ venomous barbs (defense)
Subphylum Vertebrata Chondrichthyes (cartilaginous fishes) Rays & skates Bottom feeders mollusks & crustaceans Whiplike tail w/ venomous barbs (defense)
Subphylum Vertebrata Osteichthyes (bony fishes) Endoskeleton of hard calcium phosphate matrix Operculum- protective flap Swim bladder controls buoyancy
Seahorse
Subphylum Vertebrata Amphibia first tetrapods ( two lives ) transition to land still tied to water for respiration and reproduction Gills lungs (metamorphosis) Frogs, toads, salamanders, newts
Subphylum Vertebrata Reptilia (Campbell, p. 644) (to creep) lizards, snakes, turtles, tortoises, Gila monsters, crocodiles, alligators first true land animal Scales, lungs, amniotic egg no feathers cold-blooded ectotherms (energy conservation)
Hatching reptile
Subphylum Vertebrata Fossil links Evolutionary link?? between reptiles and birds: Archaeopteryx, a Jurassuc birdreptile Clawed forelimbs Teeth Long tail w/ vertebrae
Archaeopteryx
Subphylum Vertebrata Aves (bird) feathered few flightless: ostrich, kiwi, emu breastbone with keel carina permitting flight jays, sparrows, warblers, etc
Subphylum Vertebrata Mammalia (breast) Hair or fur of keratin Active metabolism = endothermic Efficient respiration w/ diaphragm Efficient circulation w/ 4-chambered heart Layer of fat Mammary glands, tooth differentiation
Subphylum Vertebrata Mammalia (breast) Monotremes egg-laying mammals (Platypuses & echidnas spiny anteaters) Placental mammals Marsupial mammals kangaroo, opossum
Marsupial Placental Marsupial & Placental Mammals