phylum chordata subphylum vertebrata a survey of diversity
DESCRIPTION
PHYLUM CHORDATA SUBPHYLUM VERTEBRATA A SURVEY OF DIVERSITY. BIO 122: Zoology Part 2 Amphibians, Reptiles & Birds. CLASS AMPHIBIA. Amphibians : include frogs, toads, salamanders & others Tetrapods (4 legs) Have a gelatinous egg covering Have a 3-chambered heart 2 atria, 1 ventricle. - PowerPoint PPT PresentationTRANSCRIPT
PHYLUM CHORDATASUBPHYLUM VERTEBRATAA SURVEY OF DIVERSITY
BIO 122: ZoologyPart 2
Amphibians, Reptiles & Birds
CLASS AMPHIBIAAmphibians:
include frogs, toads, salamanders & others
Tetrapods (4 legs) Have a gelatinous egg covering Have a 3-chambered heart
2 atria, 1 ventricle
CLASS AMPHIBIAAmphibian 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
CLASS AMPHIBIA
CLASS AMPHIBIA Variations in developmental pattern seen:
some remain in water w/ gills: mud puppy, & few salamanders (newts)
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
CLASS AMPHIBIAVariation in respiration mechanisms: gills for aquatic forms lungs on terrestrial forms through skin (diffusion) on all forms
CLASS AMPHIBIABreathing in frogs: have lung and mouth pouch1. suck air into mouth through nostrils2. close nostrils and force air into lungs3. pull air into & out of mouth several times
(an alternate mechanism to get oxygen)4. contracting of body wall to expel air from
lungs (this is method to obtain most oxygen)
most carbon dioxide lost through diffusion out skin
CLASS AMPHIBIACaecilians - snake-like with no visible
appendages most species lack eyes food of small animals most are tropical; are either aquatic or live
in burrows
CLASS AMPHIBIASalamanders - have similar front & back
legs, a tail are carnivorous: eat worms, small
arthropods greatest diversity is in North America
CLASS AMPHIBIACLASS AMPHIBIAFrogs and toadsFrogs and toads - have longer back legs, - have longer back legs,
no tailno tail tadpoles are herbivorous, adults tadpoles are herbivorous, adults
carnivorous, largest can eat rats!carnivorous, largest can eat rats! found throughout worldfound throughout world frogs & toads are not easily frogs & toads are not easily
separated - typical: separated - typical: frog in water, toad terrestrialfrog in water, toad terrestrial
CLASS AMPHIBIACLASS AMPHIBIA South Carolina state amphibian – South Carolina state amphibian –
spotted salamanderspotted salamander
CLASS REPTILIAReptiles:
include snakes, lizards, turtles, crocodiles
Tetrapods (4 legs) leathery egg covering 3-chambered heart
CLASS REPTILIA Characteristics to separate reptiles
from amphibians include …
CLASS REPTILIA1. 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
2. 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)
CLASS REPTILIA
CLASS REPTILIA3. egg shell with food and protective
membrane allows for protective development on
land
CLASS REPTILIA4. jaw better able to grip and/or crush designed for quick
closure - larger & longer amphibian only
good to grab
CLASS REPTILIA5. reptiles have a more efficient circulatory
system and higher blood pressure left & right atrium completely separated left & right ventricles incompletely
separated, but mixing minimal
CLASS REPTILIA6. 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
CLASS REPTILIA7. nervous system more complex even with small brain, cerebrum is
relatively large
CLASS REPTILIATurtles bony case of dorsal carapace + ventral
plastron (shell) beak rather than teeth tongue not extensible
CLASS REPTILIASnakes & lizards skin of scales or plates teeth present, jaw with diapsid
anatomy (allows to open wide) tongue extensible
CLASS REPTILIASeparation 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)
CLASS REPTILIA Dinosaurs are considered
large lizards Recent studies suggest
birds are descendantsof dinosaurs
CLASS REPTILIACrocodiles (and others) skin of scales or plates teeth present, jaw without diapsid
anatomy tongue not extensible also: 4-chambered heart
CLASS REPTILIA South Carolina state reptile –
Loggerhead Sea Turtle
CLASS AVESbirds 2 legs + 2 wings calcareous egg covering 4-chambered heart
CLASS AVESOther 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
CLASS AVESFlight 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
CLASS AVESair 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)
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!
CLASS AVESTypes 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
CLASS AVESSmall species use songs for two reasons
1) 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
CLASS AVESSuperorders:
flightless birds with vestigial wings & stiff palate (ostrich, emu, kiwi)
birds with well developed wings (including penguins) and flexible palate
CLASS AVESOrders: over 20 Orders in eastern North America Orders are separated by
+ bill shape (feeding)+ foot shape+ size + other characteristics
CLASS AVES
CLASS AVES South Carolina state bird -