kingdom animalia
DESCRIPTION
Kingdom Animalia. Phylum Chordata “Vertebrates”. Organisms in this phylum are segmented animals with four distinctive features Dorsal hollow nerve cord Stiff notochord Pharyngeal slits behind the mouth Muscular post-anal tail Coelom Bilateral symmetry. Phylum Chordata “Vertebrates. - PowerPoint PPT PresentationTRANSCRIPT
Kingdom AnimaliaPhylum Chordata“Vertebrates”
Phylum Chordata“Vertebrates
• Organisms in this phylum are segmented animals with four distinctive features• Dorsal hollow nerve cord• Stiff notochord• Pharyngeal slits behind the mouth• Muscular post-anal tail• Coelom• Bilateral symmetry
Simplest Chordates
• The simplest chordates are tunicates and lancelets.• These are marine invertebrates
POST-ANAL TAIL
DORSAL, HOLLOWNERVE CORD
PHARYNGEALSLITS
MouthMuscle
segments
NOTOCHORD
LARVA
Tunicates
Simplest Chordates
HeadNOTOCHORD
DORSAL, HOLLOWNERVE CORD
Mouth
PharynxPHARYNGEALSLITS Digestive
tract
Water exit
Segmentalmuscles
AnusPOST-ANALTAIL
Lancelets
VertebratesA skull and a backbone are hallmarks of vertebrates
• Most chordates are vertebrates.• Their
endoskeletons include a skull.
• Their backbone is composed of vertebrae.
Vertebrae Backbone Skull
VertebratesMost vertebrates have hinged jaws.
• Exception: Lampreys lack hinged jaws.• They are classified as agnathans.
• Jaws evolved by the modification of skeletal supports of the gill slits.
Gillslits
Skeletalrods
Skull
Mouth
Class ChondrichthyesCartilaginous Fish
• Fish are jawed vertebrates with gills and paired fins.• Cartilaginous fish diverged before bony skeletons
appeared.• Examples: Shark and ray
Class OsteichthyesBony fish
• Bony fishes are more diverse and have– more mobile fins– operculi that move water over the gills– a buoyant swim bladder
BONY SKELETON
SWIM BLADDERGills
OPERCULUM
Class Osteichthyes
• Three sub-classes of bony fish:• Ray-finned• Lobe-finned• Lungfish
• Evolutionary evidence suggests that tetrapods evolved from lobe-finned fish.
Rainbow trout,a ray-fin
Coelacanth,a lobe-fin
• Air-breathing lungfishes that developed skeleton-reinforced appendages probably gave rise to the first amphibians.
Bonessupporting gills
Typical tetrapod limb skeleton
Class Amphibia1st Land Vertebrates
• Class Amphibia is represented today by:• frogs• toads• Salamanders
• Their limbs allow them to move on land.• However, amphibian larvae must develop in water.
Class Amphibia
• Key Characteristics:• Body Temperature: Ectotherms – obtain their body heat
from the external environment• Reproduction: Females lay eggs in water, and males
fertilize. Eggs do not have shells or outer coverings.• Examples:• Frogs and toads• Salamanders and newts• Caecilians (worm-like animal burrows in soil)
Class Reptilia1st amniotic egg
• Reptiles have more terrestrial adaptations than amphibians.
• Class Reptilia is able to live on land due to:• waterproof scales• a shelled, amniotic egg
• Modern reptiles are still ectotherms.• They warm their bodies by
absorbing heat from the environment.
Class Aves1st Endotherms
• Class Aves has: • scales• amniotic eggs• Wings• Feathers• an endothermic
metabolism• hollow bones• a highly efficient
circulatory system
Teeth(like reptile)
Wing claw(like reptile)
Feathers
Long tail withmany vertebrae(like reptile)
Class Aves
• Birds share many characteristics in common with reptiles.
• Scientists believe that birds’ feathers are evolved scales.• Consider the scaly skin of birds’ feet.
Class Mammalia
• Mammals also evolved from reptiles.• Mammals are endothermic.• There are two unique mammalian characteristics:• Hair, which insulates the body• Mammary glands, which produce milk that
nourishes their young.
Class MammaliaMonotremes
• Monotremes: a few mammals lay eggs• Example: duck-billed platypus
Class MammaliaMarsupials
• Marsupials have a short gestation.• The tiny offspring
complete development attached to the mother’s nipple, usually inside a pouch.
• Example: kangaroos
Class MammaliaPlacental Mammals
• Most mammals are eutherians, also called placentals,• They have a relatively long
gestation.• Complete embryonic
development occurs within the mother.
Phylogeny of the Animal Kingdom
• A traditional phylogenetic tree is based on patterns of embryonic development and some fundamental structures.
Porifera Platyhelminthes Mollusca Arthropoda Chordata
EchinodermataAnnelidaNematodaCnidaria
No body cavity
Pseudocoelom PROTOSTOMESCoelom fromcell masses
DEUTEROSTOMESCoelom fromdigestive tube
True coelom
Body cavity
Bilateralsymmetry
True tissues
Ancestral protists
Radialsymmetry
No true tissues
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