Vertebrate Animals Pima Medical Institute Veterinary Technician Program VTT 200 General Sciences-Biology

Phylum Chordata Animals with a developed brain and spinal cord, and extremities to aid in the movement to land, but not all have backbone

Phylum Chordata: Sub-Phyla Tunicata: very ancient group of worm like animals with a spinal cord, but no backbone (no vet importance); only found in small area of ocean near Australia Vertebrata: animals with developed brain, spinal cord AND backbone on inside (endoskeleton); -All vertebrates have developed head with sensory organs & closed circulatory & respiratory systems -All vertebrates have specialized connective tissue leading to establishment of cartilage and bone

7 Classes of Phylum Chordata Sub-phylum Vertebrata Agnothastomata (jawless fishes) Chondrichthyes (boneless fishes) Osteichthyes (bony fishes) Amphibia Reptilia Aves Mammalia

Vertebrate Chordates: simplest/most primitive form: FISH Fish are the most primitive of vertebrate chordates (Ichthyology is the study of fish) ALL FISH: Oviparous: egg layers Gill breathers Paired fins 2-chambered heart— WHY only 2 chambers needed?

Class Chondrichthyes Sharks, skates & rays Ancient class of marine fishes with predominantly cartilage structure— Very little change in thousands of years of development—excellent predators

Class Osteichthyes Osteichthyes (bony fishes) Some are marine, some are fresh water Most reproduce with external fertilization (which is less efficient because predators can eat the eggs) See “Finding Nemo”

Vertebrate Chordates-Amphibia Class Amphibia (latin for “double life” between fish & higher animals like reptiles) First creatures to live on land and sea Larva have gills; adults have lungs Scaleless skin; moist to touch First animals with 3-chambered heart, but are Ectothermic (cold-blooded) meaning they gather heat from environment

Orders of Amphibians Old named Orders of Amphibians: Anura “without tail” (frogs and toads) Urodela “with tail” Newts are aquatic; Salamanders are terrestrial

Vertebrate Chordates-Reptilia Class Reptilia (Herpetology is study of reptiles) All Reptiles: Oviparous egg-layers with amniotic sac; internal fertilization Keratinized epidermis in scales 3 chambered heart and ectothermic No gills, use lungs and air sacs

Orders of Class Reptilia Order Chelonia (beak like) scales form a shell turtles are water dwellers; tortoises terrestrial Order Crocodilia Alligators exclusive to fresh water with short & blunt snout Crocodiles are tropical with longer snout & protruding teeth Order Squamata are the snakes and lizards Sub-order Sauria are lizards Sub-order Serpentis are snakes

Vertebrate Chordates-Aves Class Aves (birds are more developed than amphibians and reptiles) Ornithology is the study of birds

Class Aves– All Birds: Epithelial tissue expressed as skin & feathers All species have rear extremities, front extremities modified into wings No teeth, utilize crop & gizzard to grind food Bones are all hollow, spongy bone for flight 4 chambered heart and endothermic (warm-blooded) can regulate temperature from within Lungs and air sacs in respiratory Internal fertilization with anatomical device called cloaca which is organ shared between urinary, digestive & reproductive systems Excellent vision organs, high metabolic rate

Class Aves Two Main divisions: Ratites (flightless birds-ostriches, emus) Carinates (with large breastbone and large breast muscle for flying & wing support)

Orders of Class Aves Orders of Carinates: Psittaciformes: (hookbills) parrots, macaws Passerformes: (soft billed perching birds) finches,canaries, Faloniformes: (raptors-carnivorous & can be predatory or scavenger) eagles, hawks Strigiformes: Owls Galliformes: (poultry) chickens, turkeys, quail Anseriformes: Waterfowl Many other orders including various storks, flamingoes, penguins, etc.

Vertebrate Chordates—Mammalia Final & Most Developed Class Mammalia What makes mammals different from other Vertebrate Chordates? (Viviparous “live birth” & mammary glands)

Class Mammalia—All Mammals: Internal Fertilization Keratinized hair layer First animals with diaphragm 4 chambered heart, circulatory system & endothermic Well developed brain and nervous system Some senses better than others depends on species Has gills as embryo developing into respiratory system with lungs after birth

Two Main Divisions of Mammals Prototheria and Eutheria Theria refers to placenta in birth What does Pro- Mean? Prototheria (no placenta in birth) Monotremes are Platypus that actually lays eggs— transition animal from reptiles and birds to mammals Marsupials like kangaroo and wallaby have pouches for carrying young

Class Mammalia—Eutheriates Eutheria (placenta during gestation) this large group includes all other mammals Many orders and sub-orders: Herbivora/ Perissodactyla (horses, rhinos) Carnivora (wolves, dogs, bears, all felines) Artiodactyla (antelope, cattle, giraffes) Cetacia (whales & dolphins) Rodentia (rats and mice) Lagomorpha (rabbits) Primates (apes and humans)