Animal Body Plans

1 st dinosaur end of dinosaurs 1 st reptiles 1 st amphibians 1 st land plants 1 st fish 1 st invertebrates Millions of Years Geologic Time Scale

Ediacaran Fauna: distinctive group of fossils dating from and existing only during Precambrian time The fauna arose about 600 mya. Named for Australia's Ediacara hills, where it was first discovered. Such fossils were later found to be widespread. These animals lived in shallow seas and had soft bodies that bear little resemblance to later life forms, and were about 1 m in length. May be an evolutionary dead end

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

Ediacaran Fauna ( MYBP) end of Precambrian era

Ediacaran Seas Mostly cnidarians and worms Sea pens

Edicarian Fauna

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

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) An explosion of body plans Hallucigena Feeding tentacles spines Similar to a sea urchin

Pikaia- earliest known chordate Burgess Shale Fauna (540 MYBP)

Burgess Shale Fauna ( MYBP Anomalocaris Opabinia Wiwaxia

Living Invertebrates

Phylogentic Relationships of Animals Ancestral Protist segmentation true tissue radial symmetry bilateral symmetry Deuterostomes: eucoelom Protostome: schizocoelem pseudo coelom Porifera Cnideria Platyhelminthes Nematoda Mollusca Annelida Echinodermata Chordata Arthropoda no true tissues acoelom

Early Embryonic Development of an Animal

Major Stages of Animal Development gametogenesis fertilization cleavage blastula gastrulation differentiation and morphogenesis gametogenesis fertilization cleavage blastula gastrulation differentiation and morphogenesis

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?

Some 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 Chordata

Major Body Plan Characteristics of Animals Symmetry Primary Germ Layers Gut Organization Body Cavity Segmentation Skeletal Systems Circulatory Systems Appendages Coloniality Symmetry Primary Germ Layers Gut Organization Body Cavity Segmentation Skeletal Systems Circulatory Systems Appendages Coloniality

Symmetry Asymmetry Radial Symmetry Bilateral Symmetry Asymmetry Radial Symmetry Bilateral Symmetry

Symmetry Radial Symmetry Bilateral Symmetry

Radial Symmetry Jellyfish Phylum Cnidaria

Pentamerous Radial Symmetry Sea Stars Phylum Echinodermata

Bilateral Symmetry Slug Phylum Mollusca

Bilateral Symmetry Squid Phylum Mollusca

Primary Germ Layers None Diploblastic Triploblast None Diploblastic Triploblast

Fates 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 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

Germ Layer Patterns Diploblastic

Diploblastic- two germ layers Phylum Cnidaria

Germ Layer Patterns Triploblastic- 3 germ layers acoelomate

Gut Organization No Gut Blind Sac Gut Complete Gut No Gut Blind Sac Gut Complete Gut

No Gut Sponges Phylum Porifera

No Gut Sponges Phylum Porifera

Blind Sac Gut Phylum Cnidaria

Complete Gut

Body Cavities Acoelomate Eucoelomate Pseudocoelomate Acoelomate Eucoelomate Pseudocoelomate

Body Cavities Acoelomate- lacks cavity between gut and outer body wall

Body Cavities Eucoelomate- body cavity completely lined with mesoderm

Body Cavities Pseudocoelomate- body cavity partially lined with mesoderm

Advantages of a Fluid-Filled Body Cavity hydrostatic skeleton greater freedom for internal organs greater body size because of body fluid circulation hydrostatic skeleton greater freedom for internal organs greater body size because of body fluid circulation

Segmentation

Centipede Phylum Arthropoda

Segmentation Lobster Phylum Arthropoda

Skeleton

Functions of the Skeleton supports basic body form protection of soft internal tissues and organs facilitates locomotion supports basic body form protection of soft internal tissues and organs facilitates locomotion

Skeleton Hydrostatic Skeletons Hard Skeletons –Exoskeletons –Endoskeletons Hydrostatic Skeletons Hard Skeletons –Exoskeletons –Endoskeletons

Hydrostatic Skeleton Sea 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 Earthworm Phylum Annelida

Exoskeleton Chiton Phylum Mollusca

Exoskeleton Stony Coral Phylum Cnidaria

Endoskeletons Vertebrates Phylum Chordata Vertebrates Phylum Chordata

Types of Appendages

Functions of Appendages locomotion feeding sensory protection locomotion feeding sensory protection

Tentacles Sea Anemone Phylum Cnidaria

Jointed Appendages Bee Appendages Phylum Arthropoda Bee Appendages Phylum Arthropoda

Circulatory Systems

Functions of Circulatory Systems transport of nutrients and metabolic wastes maintains water and solute balance defense against pathogens transport of nutrients and metabolic wastes maintains water and solute balance defense against pathogens

Circulatory System None (simple diffusion) Body Cavity Circulation Closed Circulatory System Open Circulatory System None (simple diffusion) Body Cavity Circulation Closed Circulatory System Open Circulatory System

No Circulatory System Comb Jelly Phylum Ctenophora

Circulation in a Moon Jellyfish Phylum Cnidaria

Closed Versus Open Circulatory Systems

Nervous Systems

Functions of Nervous systems integration of animal behavior processing and interpretation of sensory information elicits external and internal responses integration of animal behavior processing and interpretation of sensory information elicits external and internal responses

Types of Nervous Systems

Coloniality

Coral Phylum Cnidaria

Coloniality Sea Fan Phylum Cnidaria

Coloniality Man-of-War Phylum Cnidaria

Polymorphism in the Portuguese Man- of-War