Phylum Chordata: Phylum Chordata Charactertistics of Chordates All chordates possess a notochord. Long felxable rod between gut & nerve cord Runs most of length of animal Possess a dorsal, hollow, nerve cord Possess pharangeal slits Muscular post-anal tail


Urochordates: Urochordates Subphylum Urochordata Commonly called turnicates Sessile marine animals as adults - Motile as larva Larva possess a clear notochord which is less evident in adults Filter feed through use of siphon


Subphylum Cephalochordata: Subphylum Cephalochordata Commonly known as lancets Have all features of the ideal chordate Bury selves in sand, and filter-feed through mouth


Phylum Chordata: The Vertebrates: Phylum Chordata: The Vertebrates Subphylum Vertebrata Seven extant classes First 3 commonly called fishes Remaining 4 called tetrapods (4 feet) All possess some form of segmented vertebra


Class Agnatha: Class Agnatha Commonly known as Jawless Fish Include hagfish & Lampreys Lack paired appendages Lack bony skeleton Lack jaws Usually have circular sucking mouthparts Lampreys parasitize other fish


Lampreys: Lampreys


Hagfish: Hagfish


Class Chondrichthyes: Class Chondrichthyes Include sharks & skates, & rays Very successful class Called cartilagenous fishes because skeleton is cartilage not bone Approx. 750 species Have paired appendages Many have acute senses Sharks have a lateral-line system Allows shark to detect water pressure changes


Sharks: Sharks


Noteworthy Shark Species: Noteworthy Shark Species Great White Shark Tiger Shark Whale Shark Bull Shark


Rays & Skates: Rays & Skates Manta Ray Southern Stingray Skates


Class Osteichthes: Class Osteichthes Called Bony fish Most diverse of all fish Have skeleton made of bone Have Cycloid Scales Have paired fins Allowed evolution of 4 limbed amphibians (tetrapods) Possess scales for protection Have bony flap called operculum Allows water to be drawn over gills by fins Have Swim bladder Gas content can be manipulated allowing for changes in bouyancy


Bluefish: Bluefish


Class Amphibia: Class Amphibia First vertebrates to inhabit land Most are 4 limbed (tetrapods) Include frogs, salamanders & caecilians Have 3 chambered heart Have more complicated gas exchange organs (often a combination of lungs, gills and skin)


Order Urodela(Salamanders & Newts): Order Urodela (Salamanders & Newts) Urodela ("tailed ones" - Salamanders) More dependent on water Many species possess gills as adults


Class Apoda ("tail-less ones" - Frogs & toads) : Class Apoda ("tail-less ones" - Frogs & toads) Have more developed lungs than salamanders Lack a diaphragm & must “swallow” air Most diverse and common of amphibians. Toads are the first amphibians to evolve keratinized skin. This waterproofs the skin preventing water loss Toads must still return to water to lay eggs.


Common North American Frogs: Common North American Frogs North American Toad Green Frog Bullfrog Leopard Frog Peepers Poison Arrow Frog


Caecilia ("legless ones"): Caecilia ("legless ones")


Reproduction: Reproduction Lack internal fertilization & amniotic eggs Reproduction must occur in H2O Most species undergo metamorphosis Larval stage (tadpole) is usually an aquatic herbavore Lacks legs, respiration is through gills Develops into tetrapod adult (usually carnivorous)


Class Reptilia: Class Reptilia Includes lizards, snakes, turtles, and crocodilians Over 7000 species Possess several advanced features over amphibians Most adaptations towards independence from H2O Possess scales containing keratin Keratin is a waterproofing protein which prevents water loss in an organism Possess an amniotic egg. Prevents water loss of embryo. Allows for eggs to be laid on dry land Combined with internal fertilization, allows reptiles to reproduce independently of water Reptiles are "cold blooded" or ectotherms Cannot internally regulate body temperatures Reptiles can regulate body temperatures behaviorally (eg. Basking or swimming) Nutritional requirements are lower than warm blooded animals


The Amniotic Egg: The Amniotic Egg


Modern Reptiles: Modern Reptiles Order Chelonia (Turtles & Tortoises) Inhabit aquatic and terrestrial environment. Are herbavores, carnivores, and omnivores Characterized by possessing a hard dorsal shell Made from bone, extensions of backbone and rib cage


Common North American Turtles: Common North American Turtles


Order Squamata: Order Squamata Order Squamata (Lizards & Snakes) Most numerous & diverse of the reptiles Most relatively small Although monitors and their relatives can grow to 6' in length Herbivores, carnivores & omnivores Most able to exhibit some form of hibernation


Noteworthy Lizards: Noteworthy Lizards Eastern Fence Lizard Leopard Gecko Komodo Dragon Anole


North American Snakes: North American Snakes


Order Crocodilia (Crocodiles, Alligators, & Caimans): Order Crocodilia (Crocodiles, Alligators, & Caimans) Largest extant reptiles can grow to over 15’ and weigh over a ton Primarily aquatic they are true reptiles Inhabit warm, tropical climates Order most closely related to the dinosaurs


Crocodilians: Crocodilians Crocodile Alligator Caiman Gavail


Class Aves(The Birds): Class Aves (The Birds) Evolved from dinosaurs during Mezozoic era. Aminotic eggs and scales on legs reminants of reptilian origins Almost all adaptations of these animals are made for flight. Presence of feathers Made of keratin Can be used for insulation and flight Forelimbs developed into wings Honeycombed, light bone structure


Feathers: Feathers


Beak Types: Beak Types Absence of some organs Females usually have 1 ovary Absence of teeth lighten head Replaced by gizzard in abdomen & beak Beak made of keratin Proven very adaptable structure, having a variety of shapes for differing diets


Reproduction: Reproduction Reproduction is through hardened amniotic eggs Since birds are endothermic, these must be kept warm by parents This behavior called brooding


Birds Feet: Birds Feet


Modern Birds: Modern Birds Over 8600 species & 20 orders of birds Classified into 2 general groups Flightless species including ostrich, emus, & kiwis are known as ratites Lack sternal keel on breastbone Lack strong breast muscles needed for flight Ostrich: A ratite


Modern birds contd.: Modern birds contd. Other species capable of supporting flight called carinates 60% are "perching birds" called passeriforms Possess a sternal keel on breastbone Support strong breast muscles required for flight The sparrow: A passeriform carinate


Class mammalia: Class mammalia Approx. 4500 species of mammals Evolved from mammal-like reptiles called therapsids in the triassic period Diversified greatly following the extinction of dinosaurs Mammilian Characteristics Have Hair Made of keratin Aids in maintaining body temperature Endothermic Maintain body temperature internally Have efficient respiratory system including a diaphragm Efficient circulatory system with a 4-chambered heart Most possess placentas and give birth to live young Have mammary glands to produce milk for offspring All show parental care of offspring Have largest brains of all vertebrates Have differentiated teeth Unlike earlier vertebrates, several different teeth can exist in mammal jaws Eg. The molars & incisors in the human jaw


General Types of Mammals: General Types of Mammals Monotremes Early branch from reptilian line Include platypuses & echidnas (spiny anteaters) Only group to lay eggs (reptilian in structure) Have mammary glands to feed young Duck Billed Platypus Echidna


Marsupials: Marsupials Include opossums, kangaroos & koalas Mostly found in Australia & New Zealand Were isolated in these landmasses when the continents separated and did not evolve li the same way placental mammals did Do not develop placentas Give birth to young very early Fetuses complete development in pouch called marsupium Mammary glands found in pouch nourish young until development is complete


Examples of marsupials: Examples of marsupials Opossum Koala Kangaroo


Placental Mammals: Placental Mammals Complete embryonic development in uterus Joined to parent by organ called placenta Only "disposable" mammal organ Discarded following birth Exchanges gasses, nutrients & waste between mother and fetus


Common North American Mammals 1: Common North American Mammals 1


Common North American Mammals 2: Common North American Mammals 2