Deuterostomes

• First embryonic opening becomes the anus• Includes the phyla Echinodermata and Chordata

Echinodermata

• Marine animals• Bilateral symmetry (larvae)• Three ?ssue layers• Coelomates• Hard exoskeleton

– Name means “spiny skinned”

• Movement: water vascular system– Tube feet that create or release suc?on

• Today: Dissect starfish

Examples of bilateral larvae

Chordata

• Not all chordates are vertebrates• Chordates have the following characteris?cs as

embryos:• Dorsal (back) tubular nerve cord• A notochord

– Suppor?ve rod

• A post anal tail• Pharyngeal pouches that become gill slits

Visual of chordate characteristi cs

Tunicates (Urochordates)

• Invertebrate chordates• Adults maintain gill slits• Observe pictures and models in lab

Cephalochordates• Invertebrates• Lancelet example• Adult has all 4

characteris?cs• Observe pictures and

models in lab

Vertebrate Innova?ons• Vertebral column• Segementa?on and specializa?on• Complex brain and cephaliza?on• Jaws• Paired fins, gave rise to limbs• Gills, evolved into lungs

Today: Frog

•Amphibian•First vertebrate able to live on land• Important external

structures:– Tympanum: internal

ear/eardrum– Nares:

nostril/breathing hole

Frog Mouth• Eustacian tube: leads to ears• Maxillary and vomerine teeth• GloUs: opens to larnyx, vocal cords• Esophogus: leads to stomach

Internal Frog

• If female, find ovaries with eggs• Iden?fy two lungs (par?ally hidden by liver)

Internal Frog Conti nued

• Liver and gallbladder

• Esophagus and stomach

• Small and large intes?nes

• Pancreas and sple

• Fat bodies: store fa

ent

Internal Frog Conti nued

• Heart covered by pericardium– Three chambers (1 ventricle, 2 atria)

Internal Frog Con?nued•Kidneys (long and narrow)• Testes (yellow and oval)• Mesonephric ducts: carry urine•Cloaca: opening to outside