1. Kingdom Animalia Phylum Chordata
The vertebrates and their relatives

2. Phylum Chordata Characteristics of a chordate
A dorsal hollow nerve cord (spinal cord in vertebrates)
A notochord (most vertebrates only have a notochord during development – becomes the backbone in vertebrates)
Pharyngeal Pouches (develop into gills in fish and amphibians)
Muscular Tail (disappears in humans)

3. Subphylum Urochordata
Tunicates (also known as “sea squirts”)
Look similar to other chordates during development, but completely different as adults

4. Subphylum Cephalochordata
Lancelets: live in the ocean with their body buried in sand
Have a definite mouth and no jaws
Long pharynx with up to 100 gill slits
Breathe through their body surface
Have a simple digestive system, heart, and closed circulation
Use paired muscles to move

5. Subphylum Vertebrata 99% of chordates are vertebrates
Fish 24,000 species
Amphibian 4,000 species
Reptiles 6,000 species
Birds 10,000 species
Mammals 4,500 species

6. Fishes Aquatic vertebrates characterized by: Fins (Movement)
Scales (Protection)
Gills (Breathing)
There are fish with exceptions!
Can you name any?

7. Fish Evolution Fish were the first vertebrate to evolve
Evolved about 540 mya
Were jawless and covered in armored plates
Devonian Period = Age of the Fishes
Fish developed both jaws and fins at this time

8. Body Systems of Fishes
Fish feed in a variety of ways including parasites, carnivores, herbivores, etc.
Most fish breathe using gills
Gills are feathery filaments containing a network of capillaries to increase surface area for CO2 and O2 exchange
Fish have closed circulation

9. Body Systems of Fishes
Fish digestive systems are similar to that of humans
Ammonia is excreted by diffusion of water through gills and by use of kidneys
Salt water fish conserve bodily fluids by having concentrated urine
Fresh water fish have dilute urine
Fish that move from fresh to salt water alter their kidney function to adapt to tonicity!

10. Fish Senses Fish exhibit cephalization
Many fish have Chemoreceptors for an extraordinary sense of taste and smell
Lateral Line System – allows fish to sense movement and vibration

11. Fish Senses Swim Bladder – adjust buoyancy
How does pulling a fish from 40 feet of water affect the size of its swim bladder?

12. Fish Reproduction
Oviparous – egg laying; includes both internal (some sharks) and external (most fishes) fertilization
Ovoviviparous – eggs develop inside mother’s body and are nourished by egg yolk; young are born alive
Viviparous – the mother’s body nourishes the developing young which are born alive

13. Groups of Fishes Class Cephalospidomorphi – lamprey
Class Myxini – hagfishes
Class Chondrichthyes – cartilaginous fishes
Class Osteichthyes – bony fishes

14. Lamprey and Hagfishes Are jawless fishes Have no bones
Have mouths of soft tissue and no true teeth
Have no bones
Are the only vertebrates that do not have vertebral columns as adults

15. Lamprey
Are filter feeders as larvae and parasites that suck blood and tissues of fish as adults

16. Hagfishes
Feed on dead and dying fish using a toothed tongue to scrape a hole in the fishes side
Secrete large amounts of slime
Have 6 hearts and an open circulatory system

17. Cartilaginous Fishes
Includes sharks, rays, skates, sawfishes, and chimaeras
“Chondros” = Greek word for cartilage
A typical shark has 3000 teeth arranged in 6 to 20 rows
Not all are carnivores, the largest sharks are filter feeders
Some have flat teeth for crushing mollusks and crustaceans

18. Bony Fishes Skeletons are made of calcified bone
Includes fish we are most familiar with: Sunfish, Muskellunge, Northern Pike, Walleye, Smallmouth Bass, etc.

19. Fish Ecology Some fish can live in both salt water and fresh water
Anadromous Fishes – spend most of their life in the ocean but move to fresh water to breed
Catadramous Fishes – spend most of their life in fresh water but move to the ocean to breed

20. Class Amphibia Amphibians gave rise to all other land vertebrates
Amphibian means “double life”
As larvae they are typically aquatic filter feeders or herbivores breathing through gills
As adults most species are terrestrial carnivores that breathe through their moist skin and have lungs

21. Adaptations to Life on Land
As the amphibians developed in the late Devonian Period 360 mya they needed to adapt 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 Carboniferous Period 345 to 285 mya

22. Amphibian Body Systems
Amphibians have a well developed digestive system similar to that of humans
As most amphibians develop lungs as adults, some are lung-less and only breathe through their skin
They have closed circulation and a 3 chambered heart with a double loop system similar to that of a human
Ammonia is disposed of in urine through the use of kidneys

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

24. Amphibian Reproduction
In most cases of external fertilization, the male will attach itself to the female. Eggs and sperm are released simultaneously and encapsulated in a jelly that attaches to aquatic plants.
The jelly nourishes the developing embryos
Tadpoles hatch and metamorphose into adults

25. Amphibian Reproduction
Most amphibians abandon their eggs once they lay them.
Some care for both eggs and young
Some incubate their eggs in unusual places: in their mouth, on their back, or in their stomach

26. Amphibian Senses
Amphibians have a well developed brain and spinal cord similar to that of a fish
Eye’s are protected by a nictitating membrane
A tympanic membrane, or eardrum, is located on either side of the head
Many have a lateral line system similar to that of a fish

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

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

29. Frogs and Toads Have the ability to jump
Frogs have longer legs and can jump farther than toads
Frogs are closely tied to water; toads are more terrestrial

30. Caecilians Least known of the amphibians
Are legless and burrow in moist soil or sediment
Feed on small invertebrates such as termites
Some have scales

31. Amphibian Ecology Most are a great meal for birds and reptiles
Some have toxins to poison predators
Some have bright colors to warn of their toxins
Some mimic the bright colors of others and are harmless

32. Amphibian Ecology
Amphibian populations are declining worldwide due to several factors:
Global Warming
Decreasing Habitat
Depletion of the Ozone
Water Pollution
Introduced Aquatic Predators
Fungal Infections
Increasing human population!

33. Class Reptilia
Land vertebrates with a well developed skull, a backbone and tail, and four limbs
Exemptions: snakes have no legs, and turtles have a shell formed of fused vertebrae?
Can a turtle lose its shell?

34. Reptile Evolution
The oldest reptile fossils date back to the early Carboniferous Period some 350 million years ago
Dinosaurs of the Triassic and Jurassic Period ruled the earth until 65 million years ago

35. Reptile Body Systems
Reptiles are ectotherms – rely on interactions with the environment to control their body temperature
Reptiles have well developed lungs, four chambered hearts, and a well developed brain and spinal cord
Reptiles’ legs are rotated farther under their body than amphibians allowing them to carry weight and walk on land more efficiently

36. Reptile Reproduction
Internal Fertilization – males have a penis to place sperm in the female’s cloaca
Most are oviparous
Turtles leave their nests unattended while alligators protect their nest
Some snakes are ovoviviparous

37. Reptilian Eggs
Reptiles have amniotic eggs – named after one of the four membranes around the developing embryo
Amnion: produces watery environment around embryo
Yolk Sac: contains nutrient rich yolk that feeds embryo
Chorion: allows gas exchange
Allantois: stores waste

38. Groups of Reptiles Order Squamata: lizards and snakes
Order Crocodilia: alligators, crocodiles, caimans, and gavials
Order Chelonia: turtles, tortoises, terrapins
Order Rhynchocephalia - tuataras

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

40. Alligators, Crocodiles, and their Relatives
Long broad snout and squat appearance
Fierce carnivores
Very protective of their nests
Alligators and Caimans live only in fresh water and almost exclusively in North and South America
Crocodiles live in both fresh and salt water and are native to Africa, India, and Southeast Asia

41. Turtles, Tortoises, and Terrapins
Turtles – live in or near water
Tortoises – are terrestrial
Terrapins – live in brackish water
Carapace: Dorsal side of Shell
Plastron: Ventral side of Shell

42. Tuataras
Tuataras are the only living member of the Order Rhynchocephalia
Beak headed reptiles that live on a few small islands off the coast of New Zealand
Differ from lizards as they lack external ears and retain primitive scales
They have a legendary “third eye” which is part of a complex organs on top of the brain – the function is unknown

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

44. Class Aves Characteristics of most birds
Maintain a constant internal body temperature
Covered in feathers
Have two legs for walking and perching
Front limbs are wings
Most are adapted for flight

45. Feathers Used for flight and warmth; several types
Contour Feathers: provide the lifting force and balance needed for flight
Down Feathers: trap air close to the body and keep the bird warm
Powder Down: found on ducks and other birds that live on or in water; release a fine powder that repels water

46. Evolution of Birds
Oldest known fossil is Archaeopteryx which lived during the Jurassic Period 150 mya.
Had teeth in its beak, a jointed tail, and toes and claws on its wings
Birds are very closely related to dinosaurs, but scientists disagree on whether birds evolved from dinosaurs – or- birds and dinosaurs evolved from one common ancestor

47. Body Systems of Birds
Endotherms: can generate their own body heat; warm-blooded
Smaller birds must eat more in relation to its size due to Surface Area to Volume Ratio

48. Feeding habits of Birds
They lack teeth and therefore do not chew
Beaks are adapted to the types of food they eat
Bird Digestion
Crop: enlargement of the esophagus used to store food
Gizzard: has muscular walls and small bits of gravel used to grind food

49. Respiration
Birds have very efficient lungs that provide oxygen rich blood during both inhalation and exhalation
Inhaled air enters posterior and anterior air sacs it then travels through the lungs and is exhaled
Therefore the air flows into the air sacs and out of the lungs in one single direction, always providing oxygen rich air

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

51. Senses of Birds The brains of birds are very well developed
Birds can see color very well
Birds can hear very well
Smell or taste are not well developed

52. Bones and Muscles
Most birds can fly. Others are adapted for swimming and running
Bones are light, strong, and adapted for flight; many bones are fused to provide a study base for flight adaptations

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

54. Eggs and Incubation
Eggs are amniotic but unlike reptile eggs have a hard outer shell
Eggs must be incubated by the parents since they are endotherms
Young must be cared for after hatching

55. Groups of Birds There are nearly 30 different orders of birds
60% of all birds worldwide are perching birds
Show many examples!

56. Ecology of Birds Birds are very ecologically important
Hummingbirds are involved in pollination
Some birds eat seeds without digesting them and therefore spread the seeds
Many birds keep insect populations in check
Many birds migrate by guidance of stars, Earth’s landmarks, and Earth’s magnetic field
Birds are good indicators of environmental health; bird numbers dwindled with the use of DDT

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

58. Evolution of Mammals
The earliest mammals evolved about the same time as the early dinosaurs but remained in the shadows until the giant reptiles disappeared
First ancestors of mammals appeared during the Permian Period about 290 to 250 mya
First true mammals appeared during the Jurassic Period 210 mya

59. Mammal Evolution
When the continents split about 60 mya, three groups of mammals were isolated from one another.

60. Staying Warm Animals have hair to help insulate their bodies.
They also have subcutaneous fat to keep them warm and many have sweat glands to cool them off.
Smaller mammals have higher metabolism than larger ones in order to create enough body heat to keep warm.
Mammals eat about 10 times as much food as a reptile in order to stay warm.

61. Comparison of Vertebrate Forelimbs
When comparing the bones and bone structures of all vertebrates - birds, amphibians, reptiles, and mammals – you can see many of the same bones with very similar functions
Refer to Figure 32-7 in the text (Page 826)

62. Mammal Reproduction Internal Fertilization occurs in mammals
Mammals are divided into three groups based on methods of development and birth
Oviparous: egg-laying mammals are called monotremes
Viviparous: includes both placental mammals and marsupials

63. Caring for Young All newborn mammals feed on their mother’s milk
Some newborns are helpless at birth and must be cared for
Others are able to see and walk within minutes after birth

64. Monotremes Monotremes are the egg laying mammals
They share two notable characteristics with reptiles
Both the reproductive and urinary systems open into a cloaca
“Monotreme” means single opening
Only three species of monotremes exist today: they are found in Australia and New Guinea
Duckbill Platypus and two species of Spiny Anteaters

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

66. Marsupials
Marsupials give birth to live young that complete their development in an external pouch
Examples include kangaroos, wombats, koalas, and Tasmanian devils
A short time after internal fertilization a small embryo leaves the mother’s body, crawls across the fur, and enters the marsupium (pouch) where it attaches to a nipple to nurse

67. Placental Mammals
Placental Mammals are those that are most familiar to us.
Placenta – organ in placental mammals through which nutrients, oxygen, carbon dioxide, and wastes are exchanged between embryo and mother
Gestation – the time it takes from conception to birth in mammals (can vary from 2 weeks to 2 years depending on the mammal)

68. Orders of Mammals There are 12 orders of placental mammals
They are classified based on several criteria including
Feeding
Teeth and Jaw Structure
Foot Structure
Brain Development