Chordata
6th Period
Ashley Rouse
Kenneth Saunders
Saourya Marivada
Charateristics of Chordata
• Notochord- a stiff rod that helps support the
dorsal nerve cord and body of the organism
• Pharyngeal Slits- an opening from the neck to
the throat that helps separate food from
water and helps with gas exchange
• Dorsal Nerve Chord- lateral muscles/organs
gets messages from the brain from the nerve
fibers that are attached to the brain
• Post-anal Tail- helps organism swim, tail goes
past the anus
Urochordata (adult)
Incurrent Siphon
• Incurrent siphonwater enters
• Pharynx- water is
filtered
• Stomach- receives
food from the
water
• Excurrent Siphonsquirts out water
Excurrent
Siphon
Pharynx
Stomach
Urochordata (larva)
• Has:
– Notochord
– Dorsal, hollow nerve
cord
– Post- anal tail
• This makes them part
of the phylum
chordata
Cephalochordata (lancelets)
• Swim thru the water
using notochord
muscles
• Each muscle segment
is called a somite
Vertebrata
• 7 Classes:
–
–
–
–
–
–
–
Agnatha
Chondrichthyes
Osteichthyes
Amphibia
Reptilia
Aves
Mammalia
Agnatha
• Greek- “no jaws”
• lampreys and hagfish
• Characteristics:
– No paired appendages
(fins)
– Some attach to host
and feed off of host’s
blood
– Some eat dead fish or
marine worms
Chondrichthyes
• Chondr= Cartilage; -ichthyes= fish
• Have a jaw and paired appendages (fins)
• Subclasses:
– Elasmobranchii (sharks, rays)
– Chimaera (chimaeras)
• Lateral line system- detects vibrations in
the water
Chondrichtyes
Osteichthyes
• Oste= Bone; ichthyes= fish
• Bone endoskeleton made with hard
calcium phosphate
• Operculum- protective flap over the gills
• Swim bladder- sac filled with gas that
controls the buoyancy of the fish
• Have better control in swimming than
sharks
Osteichthyes
Amphibia
• First vertebrates on
land (salamanders,
frogs, caecilians)
• Fins evolved into legs
• “Double Life”
– Egg in water
– Mature life on land
• Cold-blooded
• Urodeles (salamander)
– “tailed ones”
• Anurans (frogs, toads)
– “tail-less ones”
– Metamorphosis- tadpole
to frog
• Apodans (caecilians)
– “legless ones”
– Live in tropical areas
and burrow into soil
Amphibia
Reptilia
• Amniotic egg allowed reptiles to reproduce
without dependence on water
• Lizards, snakes, turtles, and crocodiles
• Use solar energy to control body temp
(ectotherm)
• Adaptations for land
– Scales with keratin
– Obtain all oxygen with lungs
– Can lay amniotic eggs on land
Reptilia
Aves
• Evolved from reptiles
• Archaeopteryx- earliest
bird (Jurassic Period)
• Bird anatomy enhances
flight
– Hollow bones
– Females have one ovary
(reduces weight)
– Have larger brain than
reptile
– Very acute vision
• Endothermic (maintain
own body temp)
• 4 chambered heart
supports high
metabolism
• Ratites- flightless birds
• Carinates- birds that fly
Aves
Mammalia
• Endothermic
• Have hair and fat
layer to maintain heat
• Mothers have
mammary glands to
nourish babies
• Embryo usually grows
in uterus instead of
egg
• Monotremes
– Mammals with eggs
– platypuses
• Marsupials
– Mammals with
pouches
– Kangaroos
• Eutherian Mammals
– Placental mammals
– humans
Mammalia
Quiz Time!!
Name That Subphylum!!
Cephalochordata (lancelets)
Urochordata
Name the Class of Vertebrata
Osteichthyes
Amphibia
Aves
Chondrichthyes
Reptilia
Mammalia
Agnatha