PHYLUM CHORDATA SUBPHYLUM VERTEBRATA A SURVEY OF DIVERSITY

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PHYLUM CHORDATASUBPHYLUM VERTEBRATAA SURVEY OF
DIVERSITY

• BIO 122 Zoology
• Part 2
• Amphibians, Reptiles Birds

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CLASS AMPHIBIA

• Amphibiansinclude frogs, toads, salamanders
  others
• Tetrapods (4 legs)
• Have a gelatinous egg covering
• Have a 3-chambered heart2 atria, 1 ventricle

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CLASS AMPHIBIA

• Amphibian development is well known
• egg laid in water
• hatch into larval forms or tadpoles with gills
• lungs and leg develop, tail stops growing with
  time
• adults come out of water

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CLASS AMPHIBIA
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CLASS AMPHIBIA

• Variations in developmental pattern seensome
  remain in water w/ gills mud puppy, few
  salamanders (newts)

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CLASS AMPHIBIA

• Heart is 3-chambered
• atrium is separated into two distinct chambers
• blood circulation body ? right atrium
  ventricle ? lungs ? left atrium ventricle
• oxygen rich blood goes out to body, oxygen-poor
  blood goes to lungs

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CLASS AMPHIBIA

• Variation in respiration mechanisms
• gills for aquatic forms
• lungs on terrestrial forms
• through skin (diffusion) on all forms

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CLASS AMPHIBIA

• Breathing in frogs have lung and mouth pouch
• suck air into mouth through nostrils
• close nostrils and force air into lungs
• pull air into out of mouth several times (an
  alternate mechanism to get oxygen)
• contracting of body wall to expel air from lungs
  (this is method to obtain most oxygen)
• most carbon dioxide lost through diffusion out
  skin

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CLASS AMPHIBIA

• Caecilians - snake-like with no visible
  appendages
• most species lack eyes
• food of small animals
• most are tropical are either aquatic or live in
  burrows

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CLASS AMPHIBIA

• Salamanders - have similar front back legs, a
  tail
• are carnivorous eat worms, small arthropods
• greatest diversity is in North America

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CLASS AMPHIBIA

• Frogs and toads - have longer back legs, no tail
• tadpoles are herbivorous, adults carnivorous,
  largest can eat rats!
• found throughout world
• frogs toads are not easily separated -
  typical frog in water, toad terrestrial

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CLASS AMPHIBIA

• South Carolina state amphibian spotted
  salamander

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CLASS REPTILIA

• Reptilesinclude snakes, lizards, turtles,
  crocodiles
• Tetrapods (4 legs)
• leathery egg covering
• 3-chambered heart

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CLASS REPTILIA

• Characteristics to separate reptiles from
  amphibians include

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CLASS REPTILIA

• lungs more efficient as only mechanism for
  breathing
• reptile suck air into lungs, not force as in
  amphibians
• do so by enlarging pleural cavity or expanding
  rib cage (no diaphragm present)
• no larval stages with gills

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CLASS REPTILIA

• tough, dry, scaly skin
• offers protection against desiccation physical
  injury
• thin epidermis which is shed regularly
• well developed dermis with pigmented cells
  (chromatophores)
• scales are of keratin (derived from epidermis)

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CLASS REPTILIA

• egg shell with food and protective membrane
• allows for protective development on land

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CLASS REPTILIA

• jaw better able to grip and/or crush
• designed for quick closure - larger longer
• amphibian only good to grab

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CLASS REPTILIA

• reptiles have a more efficient circulatory system
  and higher blood pressure
• left right atrium completely separated
• left right ventricles incompletely separated,
  but mixing minimal

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CLASS REPTILIA

• reptiles have efficient strategies for water
  conservation
• presence of metanephric kidney (w/ own drainage
  - ureter)
• nitrogenous wastes are uric acid (highly
  concentrated)
• salt glands near nose or eyes

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CLASS REPTILIA

• nervous system more complex
• even with small brain, cerebrum is relatively
  large

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CLASS REPTILIA

• Turtles
• bony case of dorsal carapace ventral plastron
  (shell)
• beak rather than teeth
• tongue not extensible

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CLASS REPTILIA

• Snakes lizards
• skin of scales or plates
• teeth present, jaw with diapsid anatomy (allows
  to open wide)
• tongue extensible

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CLASS REPTILIA

• Separation of lizards snakes
• snakes generally lack pectoral and pelvic girdles
• snake vertebrae shorter wider (undulations)
• snakes lack a movable eyelid (but have a
  permanent transparent eyelids)

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CLASS REPTILIA

• Dinosaurs are considered large lizards
• Recent studies suggestbirds are descendantsof
  dinosaurs

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CLASS REPTILIA

• Crocodiles (and others)
• skin of scales or plates
• teeth present, jaw without diapsid anatomy
• tongue not extensible
• also 4-chambered heart

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CLASS REPTILIA

• South Carolina state reptile Loggerhead Sea
  Turtle

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CLASS AVES

• birds
• 2 legs 2 wings
• calcareous egg covering
• 4-chambered heart

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CLASS AVES

• Other important characteristics
• body covering body of feathers legs of scales
• forelimbs modified to wings (or fins?)
• beak with no teeth
• endothermic (body temperature by metabolism) -
  previous groups exothermic
• females with only left ovary developing
• eggs with much yolk and hard calcareous shell

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CLASS AVES

• Flight made possible by
• wings - flattened structures to catch air
  movement
• sternum with keel for attachment of flight
  muscles
• bones pneumatized (full of air cavities)
• presence of air sacs, extensions of lung into
  abdomen

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CLASS AVES

• air sacs - extensions of lung into abdomen
• up to 75 of air bypasses the lungs as breathing
  in
• flows through lungs on way out (more efficient)

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CLASS AVES

• Migration common among many species
• Summer nesting grounds, take advantage of
  abundant food in summer
• Winter feeding - migrate to other suitable site
• Arctic tern with pole to pole migration!

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CLASS AVES

• Types of annual migration patterns
• permanent resident - here year round
• summer resident - migrate here to breed during
  warm months
• winter resident - summer breeding somewhere else,
  typically further north
• summer or winter visitor - present during only
  part of year, eg. ocean birds
• spring / fall transient - moving through during
  migration
• accidental - strange presence on a very erratic
  basis

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CLASS AVES

• Small species use songs for two reasons1) warns
  other males to stay away2) attracts prospective
  females
• Once female attracted male will display
  additionally to keep female1) songs2) plumage
  displays3) dances acrobatic flights

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CLASS AVES

• Superorders
• flightless birds with vestigial wings stiff
  palate (ostrich, emu, kiwi)
• birds with well developed wings (including
  penguins) and flexible palate

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CLASS AVES

• Orders
• over 20 Orders in eastern North America
• Orders are separated by bill shape (feeding)
  foot shape size other characteristics

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CLASS AVES
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CLASS AVES

• South Carolina state bird -