1. Animal Kingdom
Vertebrates

2. Vertebrate History Overview: Half a Billion Years of Backbones
By the end of the Cambrian period, some 540 million years ago
An astonishing variety of animals inhabited Earth’s oceans
One of these types of animals
Gave rise to vertebrates, one of the most successful groups of animals

3. What’s with the Name? The animals called vertebrates
Get their name from vertebrae, the series of bones that make up the backbone

4. Vertebrate Diversity
There are approximately 52,000 species of vertebrates
Which include the largest organisms ever to live on the Earth
Vertebrates have
Vertebrae enclosing a spinal cord
An elaborate skull
Fin rays, in aquatic forms

5. Fish: The First Vertebrates
The earliest fossils are from 500 million years ago.
Highly evolved/adapted for living in water environments.

6. Water Presents Unique Challenges
How to move around
How to get air
How to float
How to sense what is around me

7. Movement Fish Shape- Fish are streamlined to minimize resistance.
Fish Skin- It is slimy, covered with mucous secretions to reduce friction
Fish Paddles- The fins of fish allow for movement.

8. Gas Exchange Water has 2.5% the free oxygen as air.
Gills- Need to be very efficient at gas exchange.
They are composed of lots of tiny folds called lamellae.
Capillary beds move in opposite direction to water flow allowing for countercurrent exchange of oxygen.

9. Gas Exchange (Cont.)
Water needs to be constantly moved over the gills.
Ram Ventilation- Adaptation of swimming with mouth open.
Operculum- A gill covering that can pump in water.

10. How to float Floating/Sinking is dependent on density.
Float=Less dense than water
Sink=More dense than water
4 Methods for floating
Low density oils
Low density bones
Fins
Pneumatic sacs- lungs or swim bladder that can be filled with air.

11. Sensory Functions Fish have eyes, nose, and ears Additionally……
Lateral line system- collection of sensory nerves that run in a line along the sides of fish.
Can sense currents or predator/prey movements.
Electroreception-Detection of electrical fields from nerves and muscles of the other organisms.

12. Class Agnatha (a- = not, without; gnatho = jaw) The lampreys.
Don’t have jaws, often parasitic
The most primitive form of fish with a true vertebrate
Lamprey

13. Two Classes of Jawed Fish
Class Osteichthyes “Bony Fish”
Class Chondrichthyes “Cartilage Fish”
Two different responses to selection pressures.
Each have advantages and disadvantages.

14. Class Chondrichthyes “Cartilage Fish”
(chondro = cartilage; ichthys = fish)
Sharks and rays
They have a cartilage skeleton, not bone.
Their backbone extends into their caudal fin

15. Class Osteichthyes “Bony Fish”
(osteo = bone)
Bony fish.
24,000 Species
Operculum
Swim bladder or lungs
90% of members fertilize externally.
Lots of eggs

16. Class Chondrichthyes Cont.
Advanced Electroreception
They also fertilize internally.
Produce fewer eggs, less young tend to die.
Lack operculum, lungs, and swim bladder

17. Class Amphibia (amphibia = living a double life)
They were the first land vertebrates.
Most either go back and forth from land to water or undergo metamorphosis.

18. Amphibian History
Early fossils of now extinct amphibian ancestors date back 400 million years.
Modern amphibians represent 3,000 species on all continents except antartica.
There are three Orders
Caudata
Anura
Gymnophiona

19. Order Caudata Salamanders and newts
Possess a tail throughout life, little leg development, most have internal fertilization, live in forest floors and caves constant moisture and temperature.
Larvae similar to adult but smaller with external gills and a tail fin.

20. Order Gymnophiona Caecilians (Rare)160 Species in tropical regions
Worm-like burrowers that feed on invertebrates in the soil.
Retractile tentacles between their eyes and nostrils may give sense of smell.
Skin covers eyes (probably blind)
Internal fertilization

21. Order Anura 4,000 species of frogs and toads
Can live in most aquatic environments
Adults highly developed hind limbs; no tails
Larval stages (tadpoles) have tails, no limbs, and are omnivores.
Primarily external fertilization
Frog and toad-less scientific “toad” normally means dry and warty skin and are more terrestrial than “frogs”.

22. Skin Skin is crucial for gas exchange 30-90%. (cutaneous respiration)
Buccal pump-when mouth and pharynx muscles push air into lungs.
Skin also used to regulate temperature (exothermic)
Skin also regulates water (osmoregulation)

23. Nervous System Amphibians have highly developed eyes.
Used for catching prey.
Nicitating membrane used for keeping eye clean and refracting light.
Anura has developed hearing for sensing prey and mating calls.

24. Population Decline Amphibian populations declining around the world.
Larval stages highly sensitive to environment
pH changes (acid rain)
UV light (depleted ozone)
Habitat destruction (human overpopulation)

25. Class Reptilia (reptili = creeping)
Dinosaurs (dino = terrible ), snakes, turtles, crocodiles, and lizards.
Reptiles have scales and are dry to the touch.
Reptiles are exothermic (exo = out, outside), they maintain body temperature through external means such as sunning on a rock or seeking shade.

26. Class Reptilia(Cont.) Dry skin with epidermal scales
Skull with one surface point touching vertebrate
Respiration via Lungs
Internal Fertilization
True amniotic egg-not only resistant to drying, but hard leathery shell and yolk for nutrients.
Water conserving Kidneys

27. Reptile Diversity and Lineage
There are 17 Orders of Reptiles, however only 4 still contain living members.
Some of the now extinct lineages have given rise to Dinosaurs, Birds, and even Mammals.
The evolutionary advancements of reptiles allowed future species to be independent of water environments and live exclusively on land.

28. Classification of Living Reptiles
Class Reptilia
Order Testudines
Order Crocodylia
Order Sphenodontida
Order Squamata
Suborder Sauria-The Lizards
Suborder Serpentes-The Snakes
Suborder Amphisbaenia-Worm Lizards

29. Order Testudines (Turtles)
There are approximately 300 species
They are characterized by bony shell, limbs that join the ribs, and keratinized beak instead of teeth.
Lay eggs, but don’t protect or provide parental care
Long time to Mature (Up to 8 years)
Long life span (For some 100+ years)

30. Order Crocodylia (Crocodiles)
21 species that were derived from archosaurs (like dinosaurs).
Unique skull openings in front of eye, triangular eye sockets, laterally compressed teeth.
Swallow prey whole
Lay eggs but display parental care and nesting.

31. Order Sphenodontida (Tuataras)
Two surviving species.
Look like lizards but are far different, have characteristics of 200 million year old fossils.
There teeth characteristics and structure are different from reptiles.
Asymmetrical organisms do not develop complex communication, sensory or motor functions.
Live in remote islands off of New Zealand

32. Order Squamata
By far the most diverse and numerous Orders of Reptiles.
Divided into 3 Suborders
Lizards
Snakes
Worm Lizards

33. Suborder Sauria (The Lizards)
4500 Species of Lizards
Have 2 pairs of Legs
Very Diverse
3 cm to 3 m in length
Some lay eggs, some don’t
Camoflauge
Long Tongues
2 are venomous

34. Suborder Serpentes (The Snakes)
2900 Species (Most not dangerous 300 ven.)
How many people die each year of snake bites?
More than 200 vertebrate and ribs for flexibility
Upper and lower jaws open independently
Eye differences between lizards and snakes
Thin elongated body has resulted in loss of lung and kidney (1 of them)

35. Suborder Amphisbaenia-Worm Lizards
135 Species
They are limbless burrowers
Distinguished from all other vertebrates by the presence of 1 tooth in upper jaw
Can move forward or backward in burrows and feed on small insects.
Also lay eggs.

36. Reptile Adaptations
Reptiles are the first vertebrates to live exlusively on land.
Many adaptations to not only survive, but flourish
Reptilia-Dry skin with scales, lungs, specialized kidneys, internal fertilization and amniotic eggs.

37. External and Locomotion
Skin has no respiratory function.
All reptiles shed the outer layer of their skin periodically, called ecdysis.
Bones have higher density (more ossification)
Ribs and vertebrate are more numerous and flexible allowing for movement.
Autotomy-Tail loss that allows lizards to escape from a predator’s grasp. Later regenerated.

38. Nutrition and Digestion
Most reptiles carnivores; few turtles are omni or herbivores.
Lizards have sticky far reaching tongues for catching prey. Chamelion tongue exceeds body length.
Jaw in snakes are loosely attached and can open independently of each other. Great for swallowing prey
Venom is secreted from modified salivary glands called fangs. It contains mixture of neurotoxins (respiratory paralysis) and hemotoxins (destroys blood vessels).

39. Circulation, Gas Exchange and Temperature Regulation
Bigger and longer bodies means the need for higher blood pressure to provide blood to all parts.
Can migrate together in hibernaculums.
Many reptiles can control blood flow.
Oxygen conservation
Temperature regulation

40. Nervous System
Highly developed nervous system allows for special adaptations that fit each species role.
Pit Organs-Heat sensitive organs that can detect hidden warm blooded prey.
Parietal Eye-Found in some reptiles (tuataras) and is a photoreceptor for detecting light.
Sea Turtles-Can detect magnetic field and return to breeding grounds that are 3,000 km away and 15 years old.
Jacobson or vomeronasal organ-Organs that provide a highly advanced sense of smell. Work in conjunction with the forked tongue of squamates.

41. Excretion and Water Regulation
Reptiles have metanephric kidneys. They are specialized to reduce water loss. (More blood filtering units called nephrons)
In fact, uric acid is secreted in paste like form as waste.
When available reptiles store large quantiites of water under skin and in bladder.
Many lizards have salt glands under eyes to secrete salt.

42. Reproduction Internal fertilization
True amniotic egg-Resistant to dessication and has a hard shell with yolk.
Sperm storage-Some female reptiles can store sperm for 4-6 years until conditions are good for offspring.
Parthenogenesis-Very special kind of reproduction in which one parent produces genetically identical offspring. Six species of lizards one of snakes. No males found in population.

43. Class Aves (avi = a bird) is the birds.
Key characteristic of birds = feathers.
Birds’ bones are light weight for flight.
Birds are endothermic (endo = within, inner) they control their body temp- erature from within.

44. Class Aves (The Birds) What makes something a bird? Bill; No teeth
Light and Hollow Bones
Endothermy
Appendages modified as feathered wings
Flexible Neck
,000 Species (27 Orders)

45. Birds: Reptiles By Another Name?
Lots of similarities between reptiles and birds
Structural: Single point of articulation between skull and vertebrae, one ear ossicle, lower jaw, and other skeletal similarities.
Physiological: Nucleated rbcs, similar liver and kidney functions.
Behavioral: Nesting and care for young (Crocodylia)

46. So Where Did Birds Come From?
Ancient Archosaurs-lineage shared by dinosaurs and crocodiles.
Looks like more closely related to dinosaurs.
Fossil evidence points to dinos—dozens of fossils were found bearing feathers.
Theropods specifically; these were bipedal dinos like T-Rex.

47. Archaeopteryx: Ancient Bird????
Illustration from the fossils found of this ancient bird/reptile. It was initally called the link between reptiles and birds, but this is very controversial. Fossils date back to 150 million years. Picture on page 343 of book.

48. Bird Feathers: What are they good for?
Today: Flight Originally: Not Flight
Early fossils with feather had too dense of bones and wrong shapes for flight.
They were probably used for:
Insulation/Temperature Regulation
Water repellency
Courtship
Camoflauge
Balancing Devices

49. Bird Feathers Flight: Provide lift and insulation
(High temperature necessary for high metabolic rate)
Courtship, Waterproofing, balance, etc.
2 Broad Types of feathers:
Pennaceous Feathers
Plumulaceous Feathers
Preening of feathers is essential-keeps them clean, rub oil for waterproofing, and “zip” back together for flight.
Feathers molt as well. 49

50. Skeleton and Muscle Head is modified to function as “hands”
Skull meets backbone at one point and neck is very flexible.
Teeth have been replaced by a bill.
Bones themselves are lightweight with tiny hollows throughout.
Flight muscles can contract quickly and fatigue slowly because of lots of mitochondria that make ATP
Interestingly, domestic chickens are bred together for more “white meat” muscle which is good to eat, but poor for flight because of low mitochondria and vascularization. 50

51. Bird Nutrition
Bird’s have crazy high metabolisms and need to eat a lot!
Hummingbird wings 80 bps
Robin’s Heart rate 600 bpm
Bill and tongue are highly adapted for their niche (role):
Eagle for tearing prey
Woodpecker for tapping into trees
Humminbird tongue unrolls to get into flower 51

52. Bird Digestion
Many birds have a crop, which is a storage pouch in the esophagus. Allows them to digest in safety or store to feed young.
Stomach has two parts:
Proventriculus (glandular stomach)-secretes digestve enzymes.
Ventriculus (gizzard)-muscular wall to crush seeds. 52

53. Circulation and Gas Exchange
Heart: Relatively large for size, rapid heart rate, and unlike reptiles complete separation of oxygenated and non-oxygenated blood.
Respiratory System: Most advanced of all tetrapods
2 Cycle inhale/exhale, which maximizes oxygen intake.
Explains how birds fly at high altitudes. 53

54. Thermoregulation
Maintain a body temperature of Celsius. ( F)
Feet of a bird have no feathers and poor blood supply. They can drop to near freezing.
During flight large amounts of heat are generated. Birds will “pant” and open mouths to allow for evaporative heat loss. 54

55. Sensory Functions Vision is important to birds
Have a unique double focusing mechanism.
Can change the curvature of their lens and cornea to allow for maximal focus on prey during flight.
Have nicitating membrane
Poor sense of smell
Similar hearing to human 55

56. Excretion Birds need to conserve water, much like reptiles.
Secrete Uric Acid
Store and reabsorb water in bladder
Have salt glands for salt secretion
This can allow sea birds to drink salt water. 56

57. Bird Mating
Bird reproduction is complex, it involves establishing territory, finding mate, constructing nests, incubating eggs, and feeding young.
All birds are oviparous
Birds only chase off others of the same species during territory establishment, threats are frequent, but fights rare.
A clear territory ensures safe nesting, food supply and better chance of offspring survival. 57

58. Bird Mating Behaviors
Most birds are monogamous for a breeding season and some for life. However, polygynous and polyandrous occurs depending on species.
Monogamy-Having one mate.
Polygynous-Having more than one female.
Polyandrous-Having more than one male.
Each has its own advantages and disadvantages. Which gives most young? Which gives best chance of survival? 58

59. Bird Nesting Nesting behavior is species specific.
Eggs need to be incubated for days.
Collection of eggs and young for a bird is called a clutch.
Lifespan in captivity is 20 years and on average in wild most birds live 1 to 2 years.
Offspring come in two forms:
Altricial-Entirely dependent on parents.
Precocial-Young are alert and lively at hatching. Normally covered in feathers. 59

60. Migration and Navigation
Birds will migrate long distances in order to avoid environmental extremes.
Non-stop fliers will store 50% of their body weight in fat.
Normally involves north and south movement.
Migration occurs due to species specific physological cues and environmental cues.
Most common cue is period of daylight.
They navigate based on visual, auditory and sometimes magnetic cues. 60

61. Class Mammalia (mamma, mammil = teat, nipple) Mammals.
Key characteristics = presence of fur/hair and mammary glands, which produce milk for young.
Most mammals bear live young

62. When/How Did Mammals Arise?
The Tertiary period about 70 million years ago.
This coincided with the reptile extinctions (dinosaurs).
Dinosaurs being gone “opened the door” to lots of niches….food and habitat sources not being used.
May have initially been nocturnal to avoid potential large reptile predators.
Living at night would have made endothermy very important.

63. Class Mammalia Mammary Glands Hair Most have live birth Diaphragm
Well developed ear
Heterodont
Four Chambered Heart
Well developed cerebral cortex
Sweat and scent glands
Endothermy

64. 3 Main Infraclasses
Monotremes-They are oviparous and have a cloaca. Ex. Duck Billed Platypus
Cloaca-Common opening for digestion, reproduction and excretion.
6 Species found only in Australia and New Guinea
Metatheria-Viviparous with a primitive placenta. Young are born early and carried in a pouch. (Marsupials)
Eutheria-Complex placenta; young are well developed before birth. (Placentals)
By far the most numerous and diverse group.
All the Orders we are about to talk about fall under this “Infraclass”

65. How Well Adapted Are Mammals?
Mammals are naturally found on every continent except Antartica.
This means we have mammals that can live in the cold, heat, dry, wet, forest, and plains.
We have limbs that with claws, hooves, wings, or flippers.

66. Mammalian Skin, A Hairy Situation
Hair is a derivative of the epidermis and is unique to mammals.
An animals coat is called pelage.
Hair is used for temperature regulation, sensory perception,
and camoflauge.

67. External Adaptations (Cont.)
Claws are present in mammals.
They are used for motion or defense.
They have evolved for each species purpose: hooves and nails
Lechien’s Feet (that’s why he wears those big shoes!)

68. Glands, a Stinky Situation
Scent/Musk Glands-Found around the face, butt and feet. Secrete pheromones involved in defense, sex, and territorial behaviors.
Do Humans have pheromones?
Sebaceous glands-Secrete oil for hair waterproofing and lubrication.
Sudoriferous glands-Sweat glands for temperature regulation.
Mammary glands-Function in female to provide young with food and antibodies.
Advanced form of parental care.

69. Mammalian Skull and Teeth
Scientists can tell mammal skulls from reptiles from the jaw bone.
In reptiles the jaw joins with two small bones at the rear, but for mammals they are gone and it joins in just one spot.
Mammals have up to 4 kinds of teeth
Incisors: In front for gnawing.
Canines: Tearing
Premolars: Chewing
Molars: Used for grinding
The number of each kind of teeth can help classify a mammal. Ex. Human 2,1,2,3 Beaver 1,0,1,3
If you knew an animal was 1, 0, 2, 5 what do you probably know about that animal? Or 3, 3, 1, 0?

70. Digestion
Each mammal species has uniquely adapted digestion for its diet.
Herbivores: Eat lots of cellulose, which is not normally digestable to our bodies.
They have a cecum: A specialized pouch that stores bacteria that break down the cellulose.
Cow, deer, and sheep have 4 stomachs each at different stages of fermentation.

71. Circulation and Gas Exchange
Like birds we have a 4 chambered heart that separates oxygenated and non oxy. blood.
The best advancement for mammals is the exchange of air, nutrients, and waste to/from fetus through the placenta.
Fetal and maternal blood vessels are intimately close, but no mixing occurs.
Unlike reptiles or birds, the diaphragm separates chest and abdominal cavity and is a muscle that contracts for mammal breathing

72. Endothermy
Most mammals live in environments that require both heating and cooling.
Heating
Shivering: Involuntary muscle contractions.
Cell Metabolism: Breakdown of food.
Cooling
Sweating: Evaporative cooling on skin.
Blood flow: Blood can be directed to surface.

73. Nervous System Highly evolved senses and brain 3 Middle ear ossicles
Vision-Controlled by Rods(light, no color) and Cones (color)
Most mammals have poor color vision and lots more rods than cones.
How does this support the idea that early mammals were nocturnal?

74. Excretion and Territory
Mammals have metanephric kidneys, but secrete urea (more watery than reptile uric acid)
Lots of mammals use urine to mark territory, access sexual readiness, and even fitness of individuals.

75. Behavior Behavior is important for mammal survival.
Grooming-Reinforces social bonds and prevents disease.
Sounds-Can warn of predators or invoke breeding
Bristling of fur-Serve as warning.

76. Reproductive Cycles & Strategies
Most mammals have a set time in which their eggs are mature and ready for fertilization.
This reproductive cycle is called the estrus cycle.
Monestrus-A single time of year. Ex. Bears
Diestrus-Twice a year. Ex. Domestic Dog
Polyestrus-Many times. Ex. Rats every 4 days
Two strategies
Delayed fertilization-Storing sperm and waiting to fertilize.
Embryonic dispause-Fertilization has occurred but embryo development is temporarily paused.
Why are these two strategies a good thing for some mammals?