Vertebrates

Phylogeny of the vertebrates: Roundworms Segmented worms Arthropods Flatworms Echinoderms Jellies Sponges Protochordates ____________ _____________ _________ Ancestral multicellular animal Vertebrates

Simplest endoskeleton is found among __________ Types of endoskeleton Simplest endoskeleton is found among __________ Composed of plate-like _________ one ossicle

Longitudinal endoskeleton occurs in Phylum _______ Better for muscle attachment, _________ Simplest form is found in the _____________ Plastic-like rod called a __________

True backbone is found only in vertebrates Backbones and skulls comprised of “____” bone ________ in sharks and their relatives

A survey of deuterostome phyla Echnioderms (“_____ skin”): Phylum: Echinodermata Sea stars, sea urchins, sand dollars Oldest deuterostomes, ~ ___ mya Endoskeleton of ________

The Chordates: Phylum _________ Subphylum Cephalochordata: the _______ Plastic-like endoskeleton = ________ No ____ backbone or skull lancelets

Subphylum Vertebrata Oldest know vertebrates: Haikou Fish, ~ ___ mya Resembled lancelets But also had a _______ and enlarged brain No paired appendages _____, but paired _______ May have evolved from segmented ______

Ostracoderms: “shell-skin” :~ ____ mya Extinct jawless fish-like vertebrates No ______ bony ____ Sifted muck through ____-like mouth Had _______ appendages

Placoderms: “_____-skin” ~ ____ mya Extinct jawed fish-like vertebrates 1st bony ___ Enabled active _________

Modern vertebrate Classes Modern Fish Branched from early jawed fish ~ ___ mya Pectoral fin Pelvic fins Paired pectoral and ______ fins 2-chambered heart, __________, poikilothermic

Tetrapods: 4-limbed ____ animals Evolved “quickly” from early ____ fish ~ ___ mya Bony bases of fish ____ became tetrapod limbs Fin rays became _____ (fingers & toes) Eusthenopteron Acanthostega Ichtyostega

Modern amphibians Frogs & salamanders Ancient origins, but many recent adaptations Ancestors survived ________ of dinosaurs Associated with ______ Skin soft, moist, more or less toxic Most _________ through skin, not _____ __-chambered heart, ectothermic, ____________

Modern Reptiles Evolved from early _________ tetrapod Adapted to life __________water _______ egg shell Dry ______ skin __-chambered heart, but _______ incomplete Ectothermic, poikilothermic Early reptiles dominated land & sea for ___ m.y.

Most dinosaurs went extinct ~___ mya Cretaceous/Tertiary “K/T” extinction Lots of _______ activity: gasses & particles in air Large asteroid, _______ & soot deposited Global cooling, inland seas receded Vertebrate taxa that survived: modern reptiles, turtles, modern amphibians, birds Gulf of Mexico Yucatan Chicxulub impact crater, ~150 mile diameter

Evolved from _________ dinosaurs ~____ mya Birds Evolved from _________ dinosaurs ~____ mya E.g., _______ carnivores such as Tyrannosaurus Scales became downy for _________ Down stiffened & elongated for _______ 4-chambered heart, endothermic, __________ Feathered theropod dinosaur

Evolved from early reptiles ~____ m.y.a. 1st true mammals ~ ___ m.y.a. Shrew-like __-chambered heart Endothermic & homeothermic Diversified after dinosaurs died out Had ecological edge over dinosaurs: - hair, endothermy, _________ red blood cells - small and _________ - _________ glands - maternal bond, great ability to learn Morganucodon

The main branches of mammals Elephants & manatees Anteaters & sloths Rodents & primates Hoofed animals, whales, carnivores & insectivores _______ mammals marsupials egg-laying mammals Reptilian ancestors

Human evolution Ape – human split: ~__ mya “Ape-men”, Australopithecus, e.g., ____ True apes remained in ____ Australopithecus took to expanding _________ Became _______ First Homo ~___ mya Several extinct Homo species recognized Large brain, ____ use, _______, & home base H. erectus spread from Africa ~ _ mya Became Beijing and ____ Man, went ____ First Homo sapiens, ~_______ years ago, Africa Evolved from H. ergaster, spread northward Adaptations over the past 100,000 yrs: Mostly ________ & _________

Geographic dispersal of Homo sapiens