Phylum Chordata

Invertebrate and Vertebrate Evolutionary Trends Radial Symmetry Coelom Pseudocoelom Protostome Development Three Germ Layers; Bilateral Symmetry Tissues Multicellularity Chordates Echinoderms Arthropods Annelids Mollusks Roundworms Flatworms Cnidarians Single-celled ancestor Deuterostome Development Sponges

Vertebrates: Phylum Chordata Lungs 4 legs Amniotic Egg (shell) Scales Endothermy Invert Common Ancestor

Evolutionary Trends in Phylum Chordata Body Plan Body Temperature Digestive System Respiratory System Circulatory System Brain

Body Plan Dorsal, hollow nerve cord Notocord Pharyngeal Pouches Tail Nerves branch from this Notocord Support rod that runs through the body below the nerve cord Pharyngeal Pouches Develop into gills Tail Notocord Hollow Nerve Cord Anus Mouth Tail Pharyngeal Pouches

Body Temperature Ectotherm Endotherm Body temp determined by temp of enviornment Fish, reptiles, amphibians Endotherm Generate and retain heat Birds and mammals

Digestive System Have organs that are adapted for feeding habits Herbivores – long system with helpful bacteria to break down plants Carnivore – short system with enzymes to break down meat

Digestive System Shark Salamander Lizard Pigeon Cow Esophagus Stomach Intestine Liver Gallbladder Pancreas Cloaca Crop Gizzard Cecum Rectum

Respiratory Systems Gills Lungs Oxygen and carbon dioxide diffuse (external) Lungs Oxygen and carbon dioxide diffuse in the lungs (internal)

Respiratory System Salamander Lizard Pigeon Primate Nostrils, mouth, and throat Trachea Lung Air sac

Circulatory System Simple Complex Single loop Gill users Double loop heart  lung AND heart  body Lung users

Circulatory System Single-Loop Circulatory System Double-Loop Circulatory System CROCODILIANS, BIRDS, AND MAMMALS FISHES MOST REPTILES

Circulatory System Types of Hearts Two Chamber Three Chamber 1 ventricle and 1 atria Fish Three Chamber 1 ventricle and 2 atria Reptiles Oxygenated and non-oxygenated blood mixes Four Chamber 2 ventricles and 2 atriums Birds, mammals, and crocodiles Most efficient! WHY??

Brain More “brain” as vertebrates become more complex