Terrestrial closely related to arthropods segmented

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Terrestrial, closely related to arthropods, segmented, unjointed, external cuticle w/ chitin, internal fertilization and eggs Arthropods Arachnids Mouthparts are chelicerae, four pairs legs Myriapods Mouthparts are mandibles, bodies consist of one head, one pair antennae, repeated segments Crustaceans Mouthparts are mandibles, two pair antennae, five pair of appendages Shrimp, lobster, pill bug Insects Mouthparts are mandibles, bodies have 3 regions, one pair antennae, 3 pair legs, air sacs and tubes allow gas exchange Most named species on earth Arthropod means jointed feet or appendages Deuterostomes Bilaterians, triploblastic, coelomate animals Echinoderms, hemichordates, lancelets, tunicates, vertebrates Echinoderms Pentaradial symmetry, internal skeleton, thin skin covering, water vasculature system and tube feet, sexual/asexual Crinoids Sea lilies (anchored), feather stars (free swimming)
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Echinozoans - no arms Sea urchins- hemispherical body form, ball socket joints on spines Sand dollars- flattened body forms, clearest visual pentaradial symmetry Sea cucumbers- elongated body, look bilateral, previously thought to be distantly related to urchins and sand dollars Asterozoans Sea stars- predatory Brittle stars- nocturnal, arms only for feeding and movement, cannot adhere, flexible arms w/ jointed plates Hemichordates Acorn worms Chordates Hollow nerve cord, notochord, pharyngeal slits/pouches, postanal tail, segmentation Lancelet Clearly shoe chordate traits Tunicates Chordate traits only visible in larvae form Vertebrates Heads, endoskeletons supported by vertebrae, internal organs suspended in coelom, circulatory system with muscular heart Fish Jaws and teeth, paired appendages (fins), internal gills, single loop blood circulation, nutritional de(fish)encies ((ha)), phylogenetic relationships Hagfish sister species to vertebrates? Lamprey may be the first vertebrates Jawed fish- anterior gill arches became jaws and greatly improved feeding efficiency Cartilaginous fish (chondrichthyans)- sharks and rays Bony fish- heavy, strong skeletons, swim bladder for buoyancy Ray-finned fish- parallel bony rays Lobe-limbed fish- muscular lobes Amphibians Legs, lungs, cutaneous respiration, pulmonary veins, partially divided hearts (3 chambers) Ichthyostega- one of the first amphibians Frogs/toads, salamanders, caecilian Reptiles Amniotic eggs, dry skin, thoracic breathing, improved kidneys (incredibly efficient), internal fertilization, ectotherms, characterized by number of openings in skull bone behind the eye (Lepidosaurs, turtles and mammals- synapsids, reptiles and birds-
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diapsids) Lizards and snakes (squamates) Generally carnivorous, paired copulatory organs, limbless, some venomous Turtles and tortoises Aquatic (turtles)/ tortoises (terrestrial), paraphyletic, no teeth, shelled, many lay eggs on land Crocodilians
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  • Fall '18
  • jessica poulin
  • Evolution, Cellular differentiation

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