Kingdom Animalia Phylum Chordata - Weebly

Adaptations to Life on Land As the amphibians developed in the lateDevonian Period 360 mya they needed toadapt to terrestrial life– Keep from drying out– Breathe using lungs, not gills– Bones in limbs allow movement– Ribs to support and protect internal organs Amphibians dominated the CarboniferousPeriod 345 to 285 mya

Amphibian Body Systems Amphibians have a well developeddigestive system similar to that of humans As most amphibians develop lungs asadults, some are lung-less and onlybreathe through their skin They have closed circulation and a 3chambered heart with a double loopsystem similar to that of a human Ammonia is disposed of in urine throughthe use of kidneys

Amphibian Reproduction Most amphibians lay their eggs in water;fertilization is external Some salamanders fertilize internally

Amphibian Reproduction In most cases of external fertilization, themale will attach itself to the female. Eggsand sperm are released simultaneouslyand encapsulated in a jelly that attaches toaquatic plants. The jelly nourishes the developingembryos Tadpoles hatch and metamorphose intoadults

Amphibian Reproduction Most amphibiansabandon their eggsonce they lay them. Some care for botheggs and young Some incubate theireggs in unusualplaces: in their mouth,on their back, or intheir stomach

Amphibian Senses Amphibians have a well developed brainand spinal cord similar to that of a fish Eye’s are protected by a nictitatingmembrane A tympanic membrane, or eardrum, islocated on either side of the head Many have a lateral line system similar tothat of a fish

Groups of Amphibians Order Urodela: Salamanders and Newts Order Anura: Frogs and Toads Order Apoda: Caecilians

Salamanders and Newts Have long bodies and tails Both adults and larvae are carnivores Most adults are terrestrial and live in dampforests Some salamanders, such as mud puppies,keep their gills and live in water all theirlives

Frogs and Toads Have the ability to jump Frogs have longer legs and can jumpfarther than toads Frogs are closely tied to water; toads aremore terrestrial

Caecilians Least known of the amphibians Are legless and burrow in moist soil orsediment Feed on small invertebrates such astermites Some have scales

Amphibian Ecology Most are a great meal for birds andreptiles Some have toxins to poison predators Some have bright colors to warn of theirtoxins Some mimic the bright colors of othersand are harmless

Amphibian Ecology Amphibian populations are declining worldwidedue to several factors with 1/3 of 6,000 specieslisted as threatened over 100 species have goneextinct in last 30 yrs. Global WarmingDecreasing HabitatDepletion of the OzoneWater PollutionIntroduced Aquatic PredatorsFungal InfectionsIncreasing human population!

Amphibian Anatomy We can use amphibian anatomy to modelour own complex anatomical systems Many of the systems we have alreadydiscussed, but we now cover them a bitmore in depth

Respiratory SystemExchanging of gases via two well developed lungsMajor Structures:1. Mouth2. Trachea3. Lungs (left & right)

Cardiovascular SystemProcess of exchanging oxygenated bloodwith deoxygenated blood via a heart aseries of arteries and veins

Cardiovascular SystemProcess of exchanging oxygenated bloodwith deoxygenated blood via a heart aseries of arteries and veins

Digestive System

Class ReptiliaCharacteristics Ectothermes- used to beknown as cold blooded Have scales Amniotic egg Dry skin 3 chambered heart (exceptcrocks)6,500 species

Class Reptilia Land vertebrates with a well developedskull, a backbone and tail, and four limbs– Exemptions: snakes have no legs, and turtleshave a shell formed of fused vertebrae? Can a turtle lose its shell?

Reptile Evolution The oldest reptile fossils date back to theearly Carboniferous Period some 350million years ago Dinosaurs of the Triassic and JurassicPeriod ruled the earth until 65 million yearsago

Reptile Body Systems Reptiles are ectotherms – rely oninteractions with the environment tocontrol their body temperature Reptiles have well developed lungs, threechambered hearts, and a well developedbrain and spinal cord Reptiles’ legs are rotated farther undertheir body than amphibians allowing themto carry weight and walk on land moreefficiently

Anatomical comparison betweenSarcopterygian, amphibian, and reptile.

Reptile Reproduction Internal Fertilization – males have a penisto place sperm in the female’s cloaca Most are oviparous– Turtles leave their nests unattended whilealligators protect their nest Some snakes are ovoviviparous

Ovipary- eggs enclosed incapsule; eggs are laid andhatched outside the motherOvovipary- give birth toyoung, eggs develop inuterusVivipary- give birth toyoung, placentalconnection

Reptilian Eggs Reptiles have amniotic eggs – named afterone of the four membranes around thedeveloping embryo– Amnion: produces watery environmentaround embryo– Yolk Sac: contains nutrient rich yolk thatfeeds embryo– Chorion: allows gas exchange– Allantois: stores waste

Amniotic EggChorionAmnionAllantoisYolk nutrients)Albumen

Groups of ReptilesOrders not important Order Squamata: lizards and snakes Order Crocodilia: alligators, crocodiles,caimans, and gavials Order Chelonia: turtles, tortoises,terrapins Order Rhynchocephalia - tuataras

Lizards and Snakes Most lizards have legs, clawed toes,external ears, and movable eyelids Some lizards do not have legs and lookmore like a snake

Alligators, Crocodiles, and theirRelatives Alligators and Caimanslive only in fresh waterand almost exclusively inNorth and South America Crocodiles live in bothfresh and salt water andare native to Africa, India,and Southeast Asia

Turtles, Tortoises, and Terrapins Turtles – live in ornear water Tortoises – areterrestrial Terrapins – live inbrackish water– Carapace: Dorsal sideof Shell– Plastron: Ventral sideof Shell

Ecology of Reptiles Many are in danger due to loss of habitat Humans also hunt them for food, pets, andtheir skins (for bags and boots) Many conservation efforts are underway,but more are needed worldwide

Evolution of Birds Oldest knownfossil isArchaeopteryxwhich livedduring theJurassic Period150 mya.

Evolution of Birds Birds are veryclosely related todinosaurs, withnew DNAsequencingadvancementsplacing strongerstatistical supportfor birds evolvingfrom earlydinosaur-likereptiles.

Class AvesCharacteristics Endotherms- Warm bloodedFeathers and wingsHollow bonesHorny billLungs have air sacksHard egg shell

Class Aves Characteristics ofmost birds– Maintain a constantinternal bodytemperature– Covered in feathers– Have two legs forwalking and perching– Front limbs are wings– Most are adapted forflight

Feathers Used for flight and warmth; several types– Contour Feathers: provide the lifting force andbalance needed for flight– Down Feathers: trap air close to the body and keepthe bird warm– Powder Down: found on ducks and other birds thatlive on or in water; release a fine powder that repelswater

Body Systems of Birds Endotherms: can generate their own bodyheat; warm-blooded Smaller birds must eat more in relation toits size due to Surface Area to VolumeRatio

Feeding habits of Birds They lack teeth and therefore do not chew Beaks are adapted to the types of foodthey eat Bird Digestion– Crop: enlargement of the esophagus used tostore food– Gizzard: has muscular walls and small bits ofgravel used to grind food

Respiration Birds have very efficientlungs that provide oxygenrich blood during bothinhalation and exhalation Inhaled air entersposterior and anterior airsacs it then travelsthrough the lungs and isexhaled Therefore the air flowsinto the air sacs and outof the lungs in one singledirection, alwaysproviding oxygen rich air

Circulation and Excretion Two loop circulatory system, similar to that ofhumans Ammonia is removed by the kidneys, convertedto high concentration uric acid and defecated(bird droppings); similar to reptiles

Senses of Birds The brains of birds are very welldeveloped– Birds can see color very well and UV light– Birds can hear very well– Smell or taste are not well developed

Bones and Muscles Most birds can fly. Others are adapted forswimming and running Bones are light, strong, and adapted forflight; many bones are fused to provide astudy base for flight adaptations

Bird Reproduction Both male and female reproductive tractsopen into the cloaca The sex organs, internal in both sexes,increase in size during mating season Birds rub their cloacas together duringmating to transfer sperm

Eggs and Incubation Eggs are amniotic but unlike reptile eggshave a hard outer shell Eggs must be incubated by the parentssince they are endotherms Young must be cared for after hatching

Ecology of Birds Birds are very ecologically important– Hummingbirds are involved in pollination– Some birds eat seeds without digesting themand therefore spread the seeds– Many birds keep insect populations in check Many birds migrate by guidance of stars,Earth’s landmarks, and Earth’s magneticfield Birds are good indicators of environmentalhealth; bird numbers dwindled with the useof DDT

Class Mammalia Characteristics of mammals– Endotherms– Have mammary glands and nurse young– Have hair

Evolution of Mammals The earliest mammals evolved about thesame time as the early dinosaurs butremained in the shadows until the giantreptiles disappeared First ancestors of mammals appearedduring the Permian Period about 290 to250 mya First true mammals appeared during theJurassic Period 210 mya

Mammal Evolution When the continentssplit about 60 mya,three groups ofmammals wereisolated from oneanother.

Staying Warm Animals have hair to helpinsulate their bodies. They also havesubcutaneous fat to keepthem warm and many havesweat glands to cool themoff. Smaller mammals havehigher metabolism thanlarger ones in order tocreate enough body heat tokeep warm. Mammals eat about 10times as much food as areptile in order to staywarm.

Comparison of VertebrateForelimbs When comparing the bones and bonestructures of all vertebrates - birds,amphibians, reptiles, and mammals – youcan see many of the same bones with verysimilar functions Refer to Figure 32-7 in the text (Page 826)

Mammal Reproduction Internal Fertilization occurs in mammals Mammals are divided into three groupsbased on methods of development andbirth– Oviparous: egg-laying mammals are calledmonotremes– Viviparous: includes both placental mammalsand marsupials

Caring for Young All newborn mammals feed on theirmother’s milk Some newborns are helpless at birth andmust be cared for Others are able to see and walk withinminutes after birth

Monotremes Monotremes are the egglaying mammals They share two notablecharacteristics with reptiles– Both the reproductive andurinary systems open intoa cloaca– “Monotreme” meanssingle opening Only three species ofmonotremes exist today: theyare found in Australia andNew Guinea– Duckbill Platypus and twospecies of SpinyAnteaters

Laying eggs and caring for young Monotremes lay eggs that are incubatedoutside the body They hatch into young animals in about 10days The young are nourished by their mother’smilk that they lick from pores on themother's abdomen

Marsupials Marsupials give birth to live young thatcomplete their development in an externalpouch Examples include kangaroos, wombats,koalas, and Tasmanian devils A short time after internal fertilization asmall embryo leaves the mother’s body,crawls across the fur, and enters themarsupium (pouch) where it attaches to anipple to nurse

Placental Mammals Placental Mammals are those that aremost familiar to us. Placenta – organ in placental mammalsthrough which nutrients, oxygen, carbondioxide, and wastes are exchangedbetween embryo and mother Gestation – the time it takes fromconception to birth in mammals (can varyfrom 2 weeks to 2 years depending on themammal)

Orders of Mammals

What’s Exam Going to LookLike See examples of practice exams onwebsite Mixture of Multiple choice Matching Short answer/fill in the blank Anatomical sectionGreat Reading Resource for Vertebrates

Targets to Know Major characteristics of Arthropoda,Echinodermata, and Vertebrata Taxonomy within each phylum (unlessotherwise stated in lecture) Evolutionary advances in respiration,circulation, locomotion and reproductionacross the phyla Know anatomical structures of bothexternal and internal from exemplars usedin class

Class Cephalaspidomorphi –lampreys Superclass Gnathostomata –with jaws Class Chondrichthyes –sharks, rays, chimaeras Class Actinopterygii –ray-finned fishes Class Sarcopterygii –lobe-fin fishes Class Amphibia –frogs, salamanders Class Reptilia –snakes, lizards, crocodiles Class Aves - birds Class Mammalia - mammals