1. Phylum Chordata

2. 3 Subphyla: Urochordata – tunicates (sea squirts)
Cephalochordata - lancets
Vertebrata - vertebrates

3. Urochordata
Tunicates (Sea squirts) are INVERTEBRATES

4. Cephalochordata
Lancets are INVERTEBRATES

5. Vertebrata
Vertebrates are …VERTEBRATES!

6. New Characteristics All members of Phylum Chordata have a Notochord
Hollow Dorsal Nerve Cord
Pharyngeal Pouches
Postanal tail

7. In vertebrates, this develops into the BACKBONE
Notochord
A rod-like structure between the digestive system and the Dorsal Hollow Nerve Cord.
In vertebrates, this develops into the BACKBONE
It anchors muscles and allows rapid movements

8. Dorsal Hollow Nerve Cord
A tube of cells
surrounding a fluid-filled
canal above the
Notochord.
This develops into
the SPINAL CORD.
The anterior portion develops into the brain and pairs of nerves connect to blocks of muscle.

9. In aquatic chordates, these develop into gill slits.
Pharyngeal Pouches
Paired opening located in the pharynx, behind the mouth.
In terrestrial chordates,
these develop into the jaw,
inner ear, and tonsils.
In aquatic chordates, these develop into gill slits.

10. Postanal Tail A tail that extends beyond the anus.
All chordates have a postanal tail at some point in their development – even humans!
Muscle blocks controlling the tail are connected to the notochord.

11. Subphylum Vertebrata Includes: FISH AMPHIBIANS REPTILES BIRDS MAMMALS
Over 50,000 species

12. Subphylum Vertebrata All Vertebrates share
A vertebral column – replaces the notochord during embryonic development
Epidermis is divided into OUTER and INNER layer –often modified to produce hair, scales, feathers, glands, horns
Endoskeleton – bony or cartilaginous
Vertebral column is stacked vertebrae that run from the head to tail. Acts as the skeletal axis for the body

13. Subphylum Vertebrata
Muscles attached to endoskeleton to provide movement
Digestive system with digestive glands, liver and pancreas
2 – 4 chambered heart
Well-developed coelom
Paired kidneys

14. Subphylum Vertebrata Two sexes with paired gonads
Head, trunk, two pairs of appendages, and post-anal tail
Myers, P "Vertebrata" (On-line), Animal Diversity Web. Accessed May 11, 2009 at

15. FISH
4 CLASSES:
Hagfishes
Lampreys
Cartilaginous Fishes
Bony Fishes

16. FISH All fish: Breathe using gills Have 2-chambered hearts
Reproduce sexually
Have developed sensory systems
Most fish (cartilaginous and bony):
Have paired fins
Have scales
Most fish are BONY fish.

17. FISH Jaws evolved in fish. can grab and crush prey
can prey on variety of organisms

18. Phylum Chordata Subphylum Vertebrata Class Amphibia

19. AMPHIBIANS Class Amphibia (amphibia = “double life”) 3 Orders:
Caudata (salamanders and newts)
Anura (frogs and toads)
Apoda (legless caecilians)

20. AMPHIBIANS Adults are terrestrial, but rely on water for reproduction
Fertilization is external
Ectotherms – body temp is variable
Undergo metamorphosis
3-chambered hearts, skin is more important for gas exchange – must stay moist

21. Amphibians Amphi – double; frogs, toads, caecilians, salamanders
Thin, moist skin
4 legs
terrestrial, but
closely tied to
water
Prefix amphi means double, amphibians have a double life – aquatic larva and terrestrial adult
must stay near water
Their thin skin puts them at risk for dessication and abrupt temperature changes. Thin skin also allows them to breathe through skin and absorb water directly- they don’t need to drink.

22. Amphibians both internal and external fertilization
eggs lack protective
membrane and shell –
need water to prevent
dessication.
Frogs and salamanders have external fertilization
Frogs – amplexus sperm covers eggs as they are released, salamanders sperm packets to cloaca (urogenital opening)
Caecilians have internal fertilization
red eye tree frog eggs

23. Ectotherms body temperature is dependent on environmental temperature
become dormant during times of year when it is too hot or too cold - estivate
Estivation is similar to hibernation, occurs when conditions are too hot or dry – not dependent on food availability, usually burrows underground where temperatures are cooloer
Spadefoot toad American SW 10 months of year, emerge at first rainfall for 24 hour breeding, egg laying frenzy!

24. Metamorphosis

25. Metamorphosis in frogs
Herbivorous tadpoles hatch with internal gills
increase in mouth and tongue size
loss of gills / formation of lungs
growth of legs, resorption of tail
new visual pigment in eyes
hemoglobin protein in blood
insectivorous adult

26. Metamorphosis in salamanders
young aquatic salamanders have gills and a tail fin
adults do not have gills or fins – breathe through skin or with lungs

27. Metamorphosis in salamanders
Some salamanders do not have larval stage, but hatch as small versions of adults

28. Circulatory System 3-chambered heart
one chamber gets oxygen rich blood from lungs
one chamber gets oxygen poor blood from body tissues
blood from both go to third chamber – blood goes to body tissues and skin
walking requires more energy and Oxygen. 3-chambered heart maintains demand.
Third chamber pumps oxygenated blood to body tissues and oxygen poor blood to skin to pick up more oxygen.

30. Order Anura Frogs and Toads
smooth, moist skin
long legs
Toads
bumpy, dry skin
short legs
Both are tailless and insectivorous

31. Order Anura Frogs and Toads
vocal cords capable of producing a wide range of sounds.
Vocal cords are sound-producing bands of tissue in the throat.

32. Order Caudata Salamanders
long, slender body with a neck and tail.
smooth, moist skin
lack claws
a few cm to 1.5 m
carnivorous

33. Order Apoda Caecilians
burrowing amphibians, have no limbs, and have a short, or no, tail.
primarily tropical animals with small eyes that often are blind.
eat earthworms and other invertebrates found in the soil.
have internal fertilization.

34. Origins of Amphibians
Most likely, amphibians arose as their ability to breathe air through well-developed lungs evolved.
The success of inhabiting the land depended on adaptations that would provide support, protect membranes involved in respiration, and provide efficient circulation.

35. Origins of Amphibians
Amphibians first appeared about million years ago.
Amphibians probably evolved from an aquatic tetrapod around the middle of the Paleozoic Era.

36. Challenges to life on land
Land life for amphibians held many dangers.
Unlike the temperature of water, which remains fairly constant, air temperatures can vary greatly.
In addition, without the support of water, the body was clumsy and heavy.

37. Challenges to life on land
Able to breathe through their lungs, gills, or skin, amphibians became, for a time, the dominant vertebrates on land.

38. REPTILES Class Reptilia 4 Orders Squamata (snakes and lizards)
Chelonia (turtles)
Crocodilia (alligators and crocodiles)
Rhynochocephalia (Tuataras)

39. REPTILES Reptiles have SCALY SKIN Reproduce on land – AMNIOTIC EGG
Legs are more directly UNDER the body
4-chambered hearts
Ectotherms

40. All birds have WINGS, but not all birds FLY!
Class Aves
8600 species of modern birds
Inhabit variety of habitats:
Antarctica
Deserts
Tropical Rain Forests
All birds have WINGS, but not all birds FLY!

41. All birds have FEATHERS and WINGS
adaptation for flight
flight muscles attached to sternum (breast bone)
Feathers
modified protein scale
molting – shedding of old feathers and growth of new feathers
wing and tail feathers lost in pairs to maintain balance

42. BIRDS Flying requires LOTS of energy!
4-chambered heart beats very fast (chickadee = 500 times/minute)
respiratory system includes air sacs – oxygenated air is circulated during INHALATION and EXHALATION.

43. BIRDS
ENDOTHERMS – maintain own body temperature, independent of environmental temperature
Reproduction – internal fertilization, shelled amniotic egg

44. Phylum CHORDATA Subphylum VERTEBRATA Class MAMMALIA

45. MAMMALS! Class Mammalia 4-chambered heart Endotherms Specialized teeth
Modified limbs
Highly developed brains
Endotherms
Produce milk for young
Hair
Diaphragms

46. MAMMALS! Hair is made out of keratin (like feathers)
developed from scales (like feathers)
arrangement provides insulation / waterproofing
conserves body heat (endotherms)

47. Endotherms maintain constant body temperatures
MAMMALS!
Endotherms maintain constant body temperatures
panting (release heat)
sweating (release heat)
shivering (generate heat)
raising hair (conserving heat)

48. Mammals have several types of GLANDS
Scent
Saliva
Hormones
Milk
Digestive enzymes

49. Mammals nurse their young
Mammary glands – secrete milk that is rich in fats, sugars, proteins, vitamins, and minerals
This continues until offspring are able to eat and digest solid food

50. The diaphragm aids in breathing
MAMMALS!
The diaphragm aids in breathing
muscle beneath the lungs, separating the THORACIC (chest) cavity from the ABDOMINAL cavity
Expands the chest cavity, bringing in air
Contracts and pushes air out

51. Mammals have a 4-chambered heart
Left and Right Atrium
Left and Right Ventricle
Oxygenated and
deoxygenated blood
are entirely separated.
Circulation removes waste and maintains HOMEOSTASIS

53. Mammalogists love teeth!
MAMMALS!
Mammalogists love teeth!
you can tell what an animal eats based on its type of teeth
teeth are adapted to type of food eaten
teeth are hard and fossilize more often than other parts of the body

54. MAMMALS!

55. MAMMALS!
This mole’s pointed incisors are used to grasp and hold small prey

56. MAMMALS!
A beaver’s incisors are modified for gnawing and can gnaw through almost anything.
These teeth continue growing throughout the animal’s lifetime.

57. MAMMALS!
A lion’s sharp canines are perfect for slicing and tearing flesh.

58. MAMMALS!
Premolars and molars are used for slicing, shearing, crushing, and grinding.

59. MAMMALS! Other characteristics include modified limbs
complex behaviors – learning and remembering

60. Mammals have complex brains
Primates (including humans) are possibly most intelligent
use tools
communicate

61. MAMMALS! 3 Orders of Mammals Monotremes (platypus and echidnas)
Marsupials (kangaroos and oppossums)
Placental Mammals (Chiroptera- bats; Rodentia – rodents; Carnivora – weasels, skunks, bears, foxes; Cetacea- whales, dolphins; Primates- chimps, apes, monkeys, humans)

62. MAMMALS! Monotremes Eggs
Only 3 species alive today (1 platypus, 2 echidnas)
Found only in Australia and New Zealand

63. Flat tail,
duck beak,
webbed feet
Coarse brown hair, covered in spines

64. MAMMALS! Marsupials short period of development in mother’s body
period of development inside pouch
most are found in Australia – opossum is North American marsupial

66. MAMMALS! Placental Mammals Over 4000 species (mostly bats and rodents)
Young develop in the UTERUS
Nourished by a PLACENTA
Development inside the mother’s body ensures protection from predators and environment during development.

67. MAMMALS!
The placenta is derived from the same membranes that surround embryos in amniotic eggs (reptiles and birds)
Marsupials also have PLACENTAE, but is short-lived

68. MAMMALS!
smallest mammals are shrews and bats and weigh as little as 3 grams
largest is the blue whale – ,000 kg! (352,739 lbs!)

69. Origin of Mammals
The first placental mammals appeared in the fossils record about 125 million years ago.
Scientists trace the origins of placental mammals from a group of mouse-sized animals to a group of reptilian ancestors called therapsids.

70. Origin of Mammals
Therapsids had features of both reptiles and mammals.
They existed between 270 and 180 million years ago.

71. Origin of Mammals
The mass extinction of the dinosaurs at the end of the Mesozoic Era, along with the breaking apart of Pangaea and changes in climate, opened up new niches for early mammals to fill.
The Cenozoic Era (65 million years to present) is sometimes called the golden age of mammals because of the dramatic increase in their numbers and diversity.
New niches opened up after mass extinction of dinosaurs around 65 million years ago