The Learning Resource goal is to use the Internet and become independent of the textbook. It is a project in progress... This page is going through major updates. If you see errors, misspellings, incorrect links, please let the instructor know in the HELP DESK. Back... Animalia (Vertebrates) General Characteristics & Classification Phylum Chordata ("Vertebrates". Animals with a backbone.) Characters in common (at least part of their life cycle -- sometimes secondarily lost): 1. gill slits 2. dorsal nerve cord 3. dorsal notochord (backbone supporting the nerve cord) 4. postanal tail Subphylum Urochordata -- tunicates, sea squirts Subphylum Cephalochordata -- lancelets Subphylum Vertebrata -- vertebrates 24.2 Vertebrate Classification Subphylum Vertebrata (Vertebrates -- "Craniates") Class Jawless fishes (Agnatha) lamprey, hagfish Note: Newer research remove the hagfishes from the vertebrates but include them in a new group called "craniates". This nullifies the name Agnatha for the lampreys. The lampreys (have a cranium and vertebrae) instead become the class Cephalaspidomorphi. Hagfishes (have a cranium but no vertebrae) become class Myxini. This classification is followed below. Class Cartilaginous fishes (Chondrichthyes) sharks, rays Class Bony fishes (Osteichthyes) all fishes with bony skeleton Class Amphibians (Amphibia) frogs, toads, salamanders Class Reptiles (Reptilia) snakes, lizards, turtles Class Birds (Aves) all organisms with feathers Class Mammals (Mammalia) Platypus, Marsupials, Placentals - evolutionary step 1: Cranium (bony frame work protecting the brain) -- previous: no cranium Class Hagfishes (Myxini -- previously Agnatha -- jawless fishes) Photo of the hagfish by C. Ortlepp, found at URL: http://www.zoology.ubc.ca/labs/biomaterials/slime.html, used for educational purposes by Dr. Jan A. Nilsson, STCC. 1. no jaws 2. Cartilaginous skeleton (no true skeleton -- no vertebrae -- notochord only) 3. Aquatic 4. "cold blooded" Poikilothermic - evolutionary step 2: Vertebrae (notochord modified to a vertebral column) -- previous: notochord only Class Lampreys (Cephalaspidomorphi -- previously Agnatha -- jawless fishes) 1. no jaws 2. Cartilaginous skeleton 3. Aquatic 4. "cold blooded" Poikilothermic Parasites def. Parasites: Ecological relationship between two organisms where only one organism benefits, by deriving nourishment from the other, without killing it (at least not immediately) but usually doing harm to it. - evolutionary step 3: Jaws -- previous: no jaws Class Cartilaginous Fish (Chondrichthyes) sharks, rays 1. Jaws 2. Cartilaginous skeleton 3. Aquatic 4. "cold blooded" Poikilothermic - evolutionary step 4: Bony vertebrae (skeleton) -- previous: cartilaginous skeleton Class Bony Fish (Osteichthyes) All other fish 1. Jaws 2. Bony skeleton 3. Aquatic 4. "cold blooded" Poikilothermic - evolutionary step 5: Limbs (living on land) -- previous: no limbs and living in water See: Movement to land – problems which needed to be overcome Class Amphibians (Amphibia) Salamanders, Frogs, Toads 1. Jaws 2. Bony skeleton 3. Terrestrial (near water) 4. "cold blooded" Poikilothermic • -- permeable skin – must live close to water to avoid water loss - evolutionary step 6: Amnion (improved land adaptation) -- previous: living near water Source: https://image.slidesharecdn.com/thevertebrates-150714122941-lva1-app6891/95/the-vertebrates-33-638.jpg?cb=1436877086 Class Reptiles (Reptilia) Snakes, Lizards, Turtles 1. Jaws 2. Bony skeleton 3. Terrestrial 4. Poikilothermic • less permeable skin (scales) – do not have to live close to water to avoid water loss (egg & body can be away from water) • amniotic egg - evolutionary step 7a: Feathers (Body temp. regulation -- improved land adaptation) -- previous: cold blooded -- temperature as the environment Class Birds (Aves) 1. Jaws 2. Bony skeleton 3. Terrestrial 4. "warm blooded" Homeothermic (feathers) • -- body temperature: Homeothermic organisms vs. Poikilothermic organisms – insulating material: feathers – the circulatory system regulate body temperature • -- Flight evolved independently in 3 groups of Animalia 1. Insects (Arthropoda) 2. Birds (Chordata) 3. Bats (Chordata) - evolutionary step 7b: Hair (Body temp. regulation -- improved land adaptation) -- previous: cold blooded -- temperature as the environment Class Mammals (Mammalia) Platypus, Marsupials, Placental mammals 1. Jaws 2. Bony skeleton 3. Terrestrial 4. "warm blooded" Homeothermic (hair) • -- body temperature: evolved independently in 2 groups of Animalia 1. Birds: – insulating material: feathers 2. Mammals: – insulating material: hair -- the circulatory system regulate body temperature • -- mammary glands -- for feeding of newborn • -- placenta – for feeding and assisting the fetus Class Mammalia (Mammals) i. Subclass Monotremes (Holotheria) -- duck-billed platypus (females lay eggs) ii. Subclass Marsupials (Metatheria) -- koala bear, kangaroo, opossum (females have pouches) iii. Subclass Placental mammals (Eutheria) Placental mammal page, fr. Biology, 7th. ed., Solomon, et.al., Brooks/Cole, Thomson Learn. Used f. educ. purposes by Dr. J.A. Nilsson, STCC. Placental mammal page, fr. Biology, 5th. ed., Raven, et.al., WBC/McGraw-Hill. Used f. educ. purposes by Dr. J.A. Nilsson, STCC. -- bats, primates, rodents, whales, carnivores, elephants, horses, pigs, deer, giraffes, rabbits (females have placenta) Order Primates (“Monkeys”: lemurs, monkeys, apes, humans) Suborder 1: Prosimians (Prosimii: tarsiers. lemurs, treeshrews, lorises) Suborder 2: Anthropoids (Anthropoidea) Infraorder 1: New World Monkeys (tail -- some prehensile tail) Infraorder 2: Old World Monkeys (rather short tail, some no tail) Superfamily: Hominoids (Hominoidea -- Apes) ----- One potential family classification: FAMILY Hylobatidae -- gibbons (Lesser Apes) FAMILY Pongidae -- orangutan, gorilla, chimpanzee, pygmy chimpanzee (Greater Apes) FAMILY Hominidae -- humans (Hominids) ----- Another potential family classification?: FAMILY Hylobatidae -- gibbons (Lesser Apes) FAMILY Pongidae -- orangutan (Asian Greater Apes) FAMILY Hominidae -- gorilla, chimpanzee, pygmy chimpanzee, humans (African Greater Apes) Family Hominidae (humans) 0.0045 billion yrsa (4.5 mya) OLDEST HOMINID FOSSILS -- Australopithecus sp. 0.003 billion yrsa (3 mya) FIRST HOMO sp. -- Homo habilis -- Homo erectus -- Homo sapiens Start of CULTURAL EVOLUTION AGRICULTURE Vertebrate diversity evolution Bozeman. Human evolution (Source: Dr. Nilsson's old lecture notes. Permission given in 2001 by McGraw-Hills then sales representative, Don Grainger, to use the picture online on lecture notes.)