bio 2 - vertebrates animals ch 32 (post)

what is the chordate phylum?

Chordata

subphylums of chordata include:

urochordata, cephalochordata, and vertebata chordata

which animals have modified scales covering their bodies, scales on their feet, lay shelled eggs, and have internal organs and skulls that provide evidence to classify them as reptiles?

birds

what are the features of the three groups of living amphibians

moist skin, metamorphosis from aquatic larvae to terrestrial adults, and ectothermic metabolism

how many ventricles are present in the heart of an amphibian and most reptiles?

1 but there are three chambers because two atrium

which fish were the first to develop jaws?

Cartilaginous fish

which vertebrate chordates were the first to develop jointed appendages?

amphibians

Reptiles and mammals terrestrial adaptations for reproduction

They developed amnion and extraembryonic membranes support the embryo and prevent it from drying as it develops

where is the postanal tail

extends beyond the anus

pharyngeal pouches

final development depends on the adult chordate

•Most vertebrates have this only in embryonic development

• in some non vert chordates this becomes functioning gills

notochord

dorsal supporting rod, replaced by vertebral column during development in vertebrates

Dorsal tubular nerve cord—nerve cord containing a fluid-filled canal

what are the four chordate characteristics?

notochord, dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail

incomplete digestive tract means

only one digestive hole

what are the vertebrate chordates?

Fishes, amphibians, reptiles, birds, mammals

lobe finned fish

fishes from the Devonian era

• fleshy appendages with bones homologous to those of terrestrial vertebrates

• Believed to be ancestral to amphibians

lancelet - nonvertebrate chordates

class Leptocardii

• notochord never becomes a vertebral column

• Live in shallow coastal waters

• Retain all four chordate characteristics as an adult

• Segmentation - muscles and branched nerve cord

vertebrate features

• have all four chordate characteristics at some time in their life history

• The embryonic notochord is replaced by a vertebral column with individual vertebrae

• Vertebral column proves vertebrate segmentation

• vertebral column is part of endoskeleton

• •Two pairs of appendages typical

• •High degree of cephalization and complex sense organs (eyes, ears)

• •Evolution of jaws provided variety of biological roles

• •Complete digestive tract and large coelom

• •Closed circulatory system

• •Efficient respiration from water or air

• Kidneys used for excretion and water regulation

the pectoral and pelvic fins of fish evolved into:

jointed appendages that allowed verebrates to move on land

milestones in veretbrate evolution

• jaw allowed for predation

• limbs allowed for locomotion

• Amnion and shelled egg allowed for reproduction on land

fish - evolution of the jaw

• cartilaginous and body fish now have them

• they are tooth bearing structures in the head that evolved from gill arches and allow predatory way of life

jawless fish

• Agnathans

• clindrical with smooth, scaleless skin, no jaws, no paired fins

• two groups: hagfishes and lampreys

hagfish - jawless fish (agnathans)

class Myxini - are scavengers

Have a skull but lack vertebrae (may have been lost)

lamprey - jawless fish (agnathans)

class cephaaspinidomorphi

• parasitic

• have a true vertebral column

• sucker mouth - attach to other fish

• Water moves in and out of gills directly; not through mouth as in other fish

cartilaginous fish

• •Sharks, skates, rays, and chimaeras

• no bone

• 5-7 gill slits

• no gill cover

• have gill chambers (called spiracles) behind their eyes

• Body covered with dermal denticles

• lateral line system

what are dermal denticles?

tiny, teethlike scales that project posteriorly

• gives sharks skin the sandpaper feel

• shark teeth are large and specialiazed versions of scales

• seen in cartilagenous fish

lateral line system

used to sense pressure caused by movement to detect prey in cartilagenous fish

bony fish

includes: ray-finned fish and lobe finned fish

• paired fins supported by thin, bony rays

• swim bladder for buoyance

• streamlined shape

• Skin covered with bony scales for protection

• blood is pumped by two chamber heart through single circuit circulatory system

how do gills work for bony fish?

Water pumped across gills → enters mouth exists gill slits (where gas exchange is)

lobe finned fish - bony fish

• Ancestors of the amphibians

• fleshy appendages that could be adapted for movement on land

• most have lungs

• The coelacanth is one type thought to have gone extinct but that has been discovered again

vertebrate circulatory pathway of fish

vertebrate circulatory pathway of amphibians and most reptiles

vertebrate circulatory pathway of some reptiles, birds, and mammals

amphibians

• means living on land and water

• includes salamanders, frogs, toads, and newts

• Caecilians are fossorial, wormlike amphibians that are limbless and spend most of the time underground

amphibians characteristics

• jointed appendages (other than in caecilians)

• four limbs

• eyelids

• ears (tympanum) to pick up sound

• larynx for vocalization

amphibians transition to land

• larger brain than in fish relative to body size

• small lungs - air goes through nose and to floor of mouth

• three chambered heart

• larval stages in water and adults on land. reproduce generally in water

reptiles

• most abundant 245-65 MYA

• include dinosaurs, ancestors of the mammals, and modern-day birds

• turtles, alligators, snakes, lizards, and birds

• ectothermic so they try regulate body temp by exposure to the sun

reptiles - amniotic egg reproduction on land

• male penis passes sperm directly into female

• fertilization is internal

• amniotic egg made development on land possible and eliminated the need for a swimming larval stage

ectothermic

animals where their body temperature is the same as that of the external environment

• fish, amphibians, living reptiles (Excluding birds)

birds - featured reptiles

• class Aves

• Feathers are modified scales; legs of birds have scales

• Amniotic egg with a hard shell instead of leathery eggs of reptiles

anatomy and physiology of birds

• features related to ability to fly

  • forelimb modified to be a wing

  • light and hoow bones

  • beak instead of jaw

  • sternum made for flight muscle attachment

  • lobular lungs with air sacs increase efficiency of gas exchange and lighten body for flight

heart/circulatory system for birds

• four chambered hearts that separate o2 rich and poor blood

• endothermic

• feathers help maintain body temp

• no bladder and excrete uric acid in semidry state

what are birds classified by?

by beak, foot type, habitat, and behavior

mammals

• evolved from reptiles

• chief characteristics: body hair and milk-producing mammary glands

• endothermic - hair provides insulation

• efficient respiratory and circulatory systems similar to birds

• double loop circulation and four chambered heart

mammal classification

monotremes, marsupials, or placental mammals

monotremes - types of mammals

• have a cloaca- terminal region of digestive tract that serves as a common chamber for feces, excretory wastes, and sex cells

• lay hard shelled amniotic eggs

• Secrete milk onto body surface (both males and females) of abdomen

  • young drink the milk

• anteaters and platypus of Australia and New Guinea

marsupials

• begin dev in female body and born immature but complete dev in pouch near abdomen w nipples of mammary glands in pouch

• kangaroo, koalas, and opossums

placental mammals

majority of this species

• classified by methods of obtaining food and mode of locomotions

• Extraembryonic membranes of the reptilian egg are modified for internal development

• dev occurs in uterus with chorion contributing to fetal part of placenta and portion of the uterine wall contribute to maternal part and maerials exchanged between fetus and moms blood at placenta

placenta mammals - adaptations to active life on land

• limbs allove for movement

• lungs expanded by rig cage and contraction of the diaphragm

• four chambered heart

• constant internal body temp

• body insulating hair

• well developed brain, enlarged due to expansion of cerebral hemispheres

placental mammals - differentiated teeth

• Incisors and canines at the front of the mouth have cutting edges for capturing and killing prey

• Premolars and molars chew food on the sides of the mouth

• shape and size associated with if they are herbivores, carnivores, or omnivores

order rodentia

placental mammals with ever growing incisors

order carinvora

placental mammals with long canine teeth

order chiroptera

placental mammals with wings supporteed by digits for flights - bats

order perissodactyla

placental mammals with long hoofed legs for speed - horses

order cetacae

placental mammals like whales with paddlelike forelimbs