Animal Body PlansAnimal Body PlansLecture 021

Criteria for Evolutionary Development & Classification

Cellular organization

Symmetry

Coelom

Digestive system

Segmentation

Cephalization

Kingdom Animalia

Symmetry

Unorganized

Radial

Bilateral

Cellular organization

Tissues, organs, systems

Coelom

Body cavity or not

Digestive system

None, 1 or 2 openings, how

Kingdom Animalia coelom

digestive tube

Segmentation

Repetition of body parts

Cephalization

Development of a “head end”

Kingdom Animalia

What to Remember

Match with common name

General characteristics

Special evolutionary features

General evolutionary location

1st dinosaur

end of dinosaurs

1st reptiles1st amphibians

1st land plants1st fish

1st invertebrates

Millions of YearsGeologic Time Scale

Ediacaran Fauna: distinctive group of fossils dating from and existing only during Precambrian time

• 600 mya

• Australia's Ediacara Hills

• Environment: shallow seas

• Description: soft bodies; worms, cnideria

• May be an evolutionary dead end

Reconstruction of the sea floor during the Vendian times when the Ediacaran organisms thrived

Ediacaran Fauna(600-540 MYBP)

end of Precambrian era

Ediacaran Fauna(600-540 MYBP)

end of Precambrian era

Ediacaran SeasEdiacaran Seas

Mostly cnidarians and worms

Sea pens

Ancient Seas at the During the Cambrian Radiation (540 MYBP)

Burgess Shale

Ancient Seas at the During the Cambrian Radiation

(540 MYBP)

Ancient Seas at the During the Cambrian Radiation

(540 MYBP)

Drawings based on fossils collected from Burgess Shale in British Columbia, Canada

Burgess Shale Fauna(540 MYBP)

Burgess Shale Fauna(540 MYBP)

An explosion of body plans

HallucigenaFeeding tentacles

spines

Similar to a sea urchin

Pikaia- earliest known chordate

Burgess Shale Fauna(540 MYBP)

Burgess Shale Fauna(540-530 MYBP

Burgess Shale Fauna(540-530 MYBP

Anomalocaris

OpabiniaWiwaxia

Living InvertebratesLiving Invertebrates

Phylogentic Relationships of AnimalsPhylogentic Relationships of Animals

Ancestral Protist

segmentation

true tissue

radial symmetry

bilateral symmetry

Deuterostomes:eucoelom

Protostome: schizocoelem

pseudocoelom

Porifera

Cnideria

Platyhelminthes

Nematoda

Mollusca

AnnelidaEchinodermata

ChordataArthropoda

no true tissues

acoelom

Early Embryonic

Development of an Animal

Early Embryonic

Development of an Animal

Major Stages of Animal Development

Major Stages of Animal Development

• gametogenesis

• fertilization

• cleavage

• blastula

• gastrulation

• differentiation and morphogenesis

Hypothetical Scheme for the Origin of Multicellularity in Animals

Hypothetical Scheme for the Origin of Multicellularity in Animals

Protostome vs Deuterostome

• Protostome: blastopore becomes mouth

• Deuterostome: blastopore becomes anus

Blastula

Blastopore

What is a Phylum?What is a Phylum?

Some Examples of Animal PhylaSome Examples of Animal Phyla

• Phylum Cnidaria– sea anemones, corals, jellyfish, man-of-wars & hydroids

• Phylum Mollusca– snails, slugs, chitons, clams, oysters, octopods & squids

• Phylum Arthropoda– spiders, scorpions, crabs, shrimp, insects & centipedes

• Phylum Echinodermata– sea stars, sea urchins, sea cucumbers & sea lilies

• Phylum Chordata– sea squirts, fish, amphibian, reptiles, birds & mammals

• Phylum Cnidaria– sea anemones, corals, jellyfish, man-of-wars & hydroids

• Phylum Mollusca– snails, slugs, chitons, clams, oysters, octopods & squids

• Phylum Arthropoda– spiders, scorpions, crabs, shrimp, insects & centipedes

• Phylum Echinodermata– sea stars, sea urchins, sea cucumbers & sea lilies

• Phylum Chordata– sea squirts, fish, amphibian, reptiles, birds & mammals

Phylum ChordataPhylum Chordata

Major Body Plan Characteristics of Animals

Major Body Plan Characteristics of Animals

• Symmetry• Primary Germ Layers• Gut Organization• Body Cavity• Segmentation• Skeletal Systems• Circulatory Systems• Appendages• Coloniality

SymmetrySymmetry

• Asymmetry

• Radial Symmetry

• Bilateral Symmetry

• Asymmetry

• Radial Symmetry

• Bilateral Symmetry

                                 

                    

SymmetrySymmetry

Radial Symmetry Bilateral Symmetry

Radial SymmetryRadial SymmetryJellyfish

Phylum CnidariaJellyfish

Phylum Cnidaria

Pentamerous Radial Symmetry

Pentamerous Radial Symmetry

Sea StarsPhylum Echinodermata

Sea StarsPhylum Echinodermata

Bilateral SymmetryBilateral SymmetrySlug

Phylum MolluscaSlug

Phylum Mollusca

Bilateral SymmetryBilateral Symmetry

SquidPhylum Mollusca

SquidPhylum Mollusca

Primary Germ LayersPrimary Germ Layers

• None• Diploblastic• Triploblast

• None• Diploblastic• Triploblast

Mesoderm

EctodermEndoderm

gut

Fates of the Primary Germ LayersFates of the Primary Germ Layers• Ectoderm

– hair, nails, epidermis, brain, nerves

• Mesoderm

– notochord (in chordates), dermis, blood vessels, heart, bones, cartilage, muscle

• Endoderm

– internal lining of the gut and respiratory pathways, liver, pancreas

The Formation of

Primary Germ Layers

The Formation of

Primary Germ Layers

The Formation of

Primary Germ Layers

The Formation of

Primary Germ Layers

Germ Layer PatternsGerm Layer Patterns

Ectoderm

Endoderm

gut

Diploblastic

Diploblastic- two germ layersDiploblastic- two germ layersPhylum CnidariaPhylum Cnidaria

Germ Layer PatternsGerm Layer Patterns

acoelomate

Triploblastic: 3 germ layers

Mesoderm

EctodermEndoderm

gut

• No Gut

• Blind Sac Gut

• Complete Gut

Gut OrganizationGut Organization

No GutNo GutSponges

Phylum PoriferaSponges

Phylum Porifera

No GutNo GutSponges

Phylum PoriferaSponges

Phylum Porifera

Blind Sac GutBlind Sac GutPhylum CnidariaPhylum Cnidaria

Complete GutComplete Gut

• Acoelomate

• Eucoelomate

• Pseudocoelomate

Body CavitiesBody Cavities

Body CavitiesBody Cavities

Acoelomate- lacks cavity between gut and outer body wall

Mesoderm

EctodermEndoderm

gut

Body CavitiesBody Cavities

Eucoelomate- body cavity completely lined with mesoderm

Mesoderm

Ectoderm

Endoderm

coelom

gut

Body CavitiesBody Cavities

Pseudocoelomate: body cavity partially lined with mesoderm

Mesoderm

EctodermEndoderm

pseudocoelom

gut

• hydrostatic skeleton

• greater freedom for internal organs

• greater body size because of body fluid circulation

Advantages of aFluid-Filled Body

Cavity

Advantages of aFluid-Filled Body

Cavity

SegmentationSegmentation

SegmentationSegmentationCentipede

Phylum ArthropodaCentipede

Phylum Arthropoda

SegmentationSegmentationLobster

Phylum ArthropodaLobster

Phylum Arthropoda

SkeletonSkeleton

Functions of the SkeletonFunctions of the Skeleton

• supports basic body form

• protection of soft internal tissues and organs

• facilitates locomotion

SkeletonSkeleton

• Hydrostatic Skeletons

• Hard Skeletons

– Exoskeletons

– Endoskeletons

Hydrostatic Skeleton

Hydrostatic SkeletonSea Anemone

Phylum CnidariaSea Anemone

Phylum Cnidaria

Hydrostatic Skeleton:• A non compressible fluid held under

pressure in a closed body compartment.

• Uses antagonistic muscles for movement.

• The gastrovascular cavity of the jellyfish acts as hydrostatic skeleton against which contractile cells can work.

Hydrostatic Skeleton

Hydrostatic Skeleton

EarthwormPhylum Annelida

EarthwormPhylum Annelida

ExoskeletonExoskeleton

ChitonPhylum Mollusca

ChitonPhylum Mollusca

ExoskeletonExoskeletonStony Coral

Phylum CnidariaStony Coral

Phylum Cnidaria

EndoskeletonsEndoskeletonsVertebrates

Phylum ChordataVertebrates

Phylum Chordata

Types of AppendagesTypes of Appendages

Functions of AppendagesFunctions of Appendages

• locomotion

• feeding

• sensory

• protection

TentaclesTentaclesSea Anemone

Phylum CnidariaSea Anemone

Phylum Cnidaria

Jointed AppendagesJointed Appendages

Bee AppendagesPhylum ArthropodaBee Appendages

Phylum Arthropoda

Circulatory SystemsCirculatory Systems

Functions of Circulatory SystemsFunctions of Circulatory Systems

• transport of nutrients and metabolic wastes

• maintains water and solute balance

• defense against pathogens

Circulatory SystemCirculatory System

• None (simple diffusion)

• Body Cavity Circulation

• Closed Circulatory System

• Open Circulatory System

No Circulatory SystemNo Circulatory SystemComb Jelly

Phylum CtenophoraComb Jelly

Phylum Ctenophora

Circulation in a Moon JellyfishCirculation in a Moon JellyfishPhylum CnidariaPhylum Cnidaria

Closed Versus Open Circulatory SystemsClosed Versus Open Circulatory Systems

Nervous SystemsNervous Systems

Functions of Nervous systemsFunctions of Nervous systems

• integration of animal behavior

• processing and interpretation of sensory information

• elicits external and internal responses

Types of Nervous SystemsTypes of Nervous Systems

ColonialityColoniality

ColonialityColonialityCoral

Phylum CnidariaCoral

Phylum Cnidaria

ColonialityColonialitySea Fan

Phylum CnidariaSea Fan

Phylum Cnidaria

ColonialityColoniality Man-of-War

Phylum Cnidaria Man-of-War

Phylum Cnidaria

Polymorphism in the Portuguese Man- of-War

Polymorphism in the Portuguese Man- of-War