Animals 3-1 New Phylum- ChordataNew Phylum- Chordata Members of this phylum are called chordates Members of this phylum are called chordates All chordate have three things in commonAll chordate have three things in common 1.Notochord 2.Nerve cord 3.Pharyngeal slits Notochord – a flexible rod that supports an animal’s back becomes backbone in adult animal

Animal 3-1 Cartilage – strong flexible tissue that is softer than bone (ear lobe/nose) Pharyngeal slits – slits that help in the breathing process Vertebrae -(singular vertebra) bones that make up a vertebrates backbone. Spinal cord passes through vertebrae

Animals 3-1 The endoskeleton supports and protects the body, helps give shape, and gives muscles a place to attach 1.Backbone- provides support, protection and flexibility 2.Skull- protects the brain and sense organs 3.Ribs protect heart lung and other organs 4.Arm and leg bones help with movement

Animals 3-1 Endoskeletons grow along with the animal, vertebrate animals tend to be larger than invertebrates Vertebrates can be grouped by how they control their body temperature Ectotherm – an animal whose body does not produce much heat. Body temp changes with environment. Ex. Fishes amphibians reptiles

Animal 3-1 (notes) Ectotherms are called cold blooded, body temp is usually similar to environment Endotherm –is an animal whose body controls and regulates its temperature by controlling the internal heat it produces. Body temp. doesn’t usually change much, has adaptations to help control temp; fur feathers, sweat glands. Can live in more various environments than ectotherms

Animals 3-1 Earliest vertebrates may have been fishes Amphibians probably descended from fish Reptiles may have descended from amphibians Mammals and birds may have descended from reptiles

Animals 3-2 Fish – ectothermic vertebrate that lives in the water, has fins, and most obtain oxygen through gills and most have scales. (notes) Fish make up the largest group of vertebrates 50% Swimming on Earth 500 million years longer than any other vertebrate. Fish have a closed circulatory system. Blood pumps in one continuous loop

Animals 3-2 Fish use fins for movement-mostly feeding Teeth are adapted for eating Highly developed nervous system and sense organs Most fish fertilize externally Three Major groups of fish 1.Jawless 2.Cartilaginous 3.Bony

Animals 3-2 Jawless Fish -earliest vertebrates -skeletons made of cartilage -no pairs of fins -no scales Two types of jawless fish 1.Hagfish- large worm like crawl into dead or decaying fishes, use sandpapery tongue to scrape and consume tissue 2.Lampreys- parasites that attach to live fishes and suck on tissue and blood of host

Animals 3-2 Cartilaginous Fishes -Sharks, Rays, and Skates -Skeleton made of cartilage -Pairs of fins -Has a jaw -pointed tooth like scales -all are carnivores -sharks cannot move water over their gills, they must keep moving or rely on the current to move water over their gills

Animals 3-2 Bony Fish -most familiar type of fish -scales distinguishing characteristic -lateral lines detect vibrations and pressure changes Swim bladder- an internal gas-filled sac that helps the fish stabilize its body at different depths Buoyant force- force water exerts upward on any underwater object

Animals 3-3 Amphibian- ectothermic vertebrate that spends its early life in the water and most spend their adult life on land. Amphibian = “double life” (notes) Amphibians Metamorphosis 1.Start as eggs coated in clear “jelly” 2.Hatch into larvae with gills 3.Develop into adults ( most with lungs) 4.Spend adult life on land NEAR water

Animals 3-3 Amphibian Circulatory System

Animals 3-3

Left Atrium- upper chamber receives oxygen rich blood from the lungs. Right Atrium- upper chamber receives oxygen poor blood from the body Ventricle- lower chamber of heart, pumps mixed oxygen leveled blood to the lungs.

Animals 3-4 Snakes live almost anywhere between 69 degrees north and south latitude Snakes more steamlined lizards= no legs eyelids, external ears, most 1 lung

Animals 3-4 Muscles attached to the ribs and backbone move the animal by alternating contracting muscles on either side of it’s body. All snakes are carnivores snakes have special adaptations for capturing and eating prey Turtles- shell made from ribs and backbone, shell made from large scales same found on the skin.

Animals 3-4 Many turtles carnivores, all turtles have special adaptations for eating Crocodilians- carnivores feed mostly at night, care for young after hatching Alligators, crocodiles, caiman Alligator- broad round snouts with only a few teeth showing Crocodile- narrow snout you can see most teeth

Animal 3-4 Dinosaurs may have been endothermic, because of their size. No one 100% sure of the reason for their extinction Fossil- hardened remains or other evidence of a living thing that existed Sedimentary rock- made of hardened layers of sediment (clay, sand, mud, silt) Paleontologist- scientist that studies extinct organisms, fossil structures, modern animals.