What is an amniote? What are some distinguishing characteristics that make them

different from non-amniote tetrapods?

• Group of vertebrates with terrestrially adapted egg containing amniotic fluid
• Characteristics
  • Amniotic egg
  • Waterproof skin
  • Skin elaborations (scales, feathers, hair)
  • Costal (rib) ventilation of lungs
  • Longer neck
  • Elaborate schoulder muscles
  • Brachial plexus (more complex innervation of limbs)

• Formation of extrambryonic membranes
• Folds over to create membranes surrounding yolk sac

• Family of reptile like amphibians that gave rise to first amniotes
• Possible driven by insect radiations in the late carboniferous or by radiations of terrestiral vegetation
• At end of permian, major extinction of most terrestrial nonamniotes so from mesozoic onward amniotes dominated

Name the two major lineages of amniotes (present in fossil record by mid-

Carboniferous). Give some examples of each.

• Synapsids
  • mammal-like reptiles
  • mammals
• Sauropsids
  • turtles
  • lizards/snakes
  • crocodilians
  • dinosaurs/birds

• Endothermy -> high metabolic rates, insulation
• Parental care
• Complex social behavior

Describe how locomotory adaptations were related to breathing constraints. Compare

and contrast how these were achieved in synapsids and sauropsids.

• Need to run for long distance, couldn't breathe while running, needed to fix this
• Need steady supply of oxygen, since muscles use more of it while running
• Synapsids - shifted primary site of respiratory movements from rib cage to the diaphragm
  • Reduced ribs
  • Limbs beneath body
  • Diaphragm
• Sauropsids - rib cage as primary method of creating pressue differences to move air in and out of lungs
  • Gastralia (belly ribs)
  • Pelvic movements
  • Limbs beneath body
  • Bipedalism

• Rapid locomotion requires system that can take up oxygen and release carbon dioxide quickly while retaining water
• Sauropods
  • Alveolar lung
  • Airflow is in and out (a tidal-flow lung)
• Synapsids
  • Faveolar lung
  • Airflow is one way through the lung (a through-flow lung)

In terms of number of species, which group (synapsids or sauropsids) were the most

successful? What is a possible explanation for this difference?

• Sauropsids are more successful
  • > 17,000 species
  • Synapsids (~4,800)
• Sauropsids occupy all adaptive zones occupied by synapsids plus additional ones

What is an adaptive zone? Give examples? What is meant by a key innovation? Give

examples.

• Adaptive zone - set of similar ecological niches occupied by a group of related species, constituting a higher taxon
• Key innovation or adaption - allows occupating of a new adaptive zone
• Examples
  • Snake-like adaptive zone - loss of legs (caecilians, snakes)
  • Marine/aquatic adaptive zone - flippers, torpedo shaped body
  • Aerial adaptive zone - wings (birds-diurnal, bats-nocturnal)

How do synapsids, anapsids, and diapsids differ in terms of temporal fenetrae? What is

the functional significance of temporal fenestrae?

• Anapsid - no hole in their head
• Synapsids - upper and lower fenetrae joined
• Diapsid - two holes
• Significance: provide room for muscles to bulge
  • Room for complex jaw muscles

What do you know about turtles? What are the two main groups of turtles, and how do

they differ?

• Internal fertilization; all lay eggs on land; parental care in one species
• Longevity: up to 200 yrs
• 50% of species are at risk
• at least 7 species have gone extinct recently
• Cryptodires - bend neck into vertical s-shaped curve
• Pleurodires - bend neck to the side

• Vetebral columns and ribs are connected to dermal bones of shell
• Covered with carapace made of epidermal scutes

• Limb girdles are inside the rib cage
• Ribs and vertebae are fused to carapace

• Depending of temperature surrounding eggs-incubation temp, hatchlings could be male or female
• High temperatures (higher than 30 C) - female

How do turtles get by with a three-chambered heart? What is the function of the

pulmonary/systemic shift (right-to-left shunt) in the circulatory system of many reptiles?

• Blood can be shifted between pulmonary and systemic circuits
• shunt - match patterns of lung ventilation and pulmonary gas flow
  • stabilize oxygen concentration in bood during alternating periods of apnea and breathing
  • Reduce blood flow to lungs during breath-holding (e.g. diving, head retraction)
    Enhance digestion (secretion of gastric acid)

How many turtle species are found in New York State? Name a few (common names

okay, extra credit for correct scientific names).

• Common map turtle (graptemys geographica)
• Eastern box turtle (terrapene carolina)
• Eastern spiny softshell turtle (apalone spinifera)
• Painted turtle (chrysemys picta)

What is a lepidosaur? Give some examples. How are lepidosaurs related to other

diapsids?

• Tautara, lizards and snakes
• Skin covered by scales and impermeable to water 
• Sister lineage to archosaurs

• Lizards and snakes

Why is it better to call lepidosaurs ectotherms than “cold blooded”? How do lepidosaurs control their body temperature?

• Their body temperature changes with their environment - can't live in some environments because of it
• Can use physiological mechanisms to adjust their rate of temperature change using peripheral circulation
• Dialation of blood vessels = more blood flow = warms

• Iguanids - Iguanas
• Chameleonids - Chameleons
• Gekkonids - Gekkos

What explains the evolution of leglessness in squamates? What might be a good way to

tell a legless lizard from a snake?

• Adapted for locomotion in dense grass or other vegetation, and/or fossorial (borrowing)
• Integument is free of attachment to trunk, body can slide back and forth inside integumentart tude
• Legless lizards
  • Have problems swallowing prey

• Compared with legless lizards
  • Reduction of body diameter
  • Elongation, rearrrangement of internal anatomy
  • Left lung is reduced

• Boidae - Boas and Pythons
• Elapsids - Cobras
• Viparids - Vipers

• Mobility of head skeleton 
• Kinetic skull via loss of temporal arch and freeing up of the quadrate and squamosal bones
• Advantage
  • Can swallow larger prey
• Disadvantage
  • Risk of damage to the snake and possibly death

• Kinetic skull
• Loss of temporal arches increasing flexibility of skull joints
• S mobile links on each side of head, so each set of jaws can move individually
• Sideways movement as well as rotation
• Mandables loosely connected in front so that jaw tips can spread - jaws walk over prey

What are the main functions of venom in snakes? Describe the variation seen in the

jaws and fangs of venomous snakes.

• Immobilize prey
• Kill prey
• Enlarged teeth (fangs) on the maxillae
• Opisthoglyphous
  • Have one or more enlarged teeth near the rear of the maxilla, with smaller teeth in front
• Proteroglyphous
  • Hollow fangs located at the front of the maxilla, several small, solid teeth behind the fangs, always erect
• Solenoglyphous
  • Hollow fangs are the only teeth on the maxillae, which rotate so that the fangs are folded against the roof of mouth when jaws are closed

• Allow them to smell and sense which direction a smell is coming from

What might explain why snakes are such a successful group? What was the advantage

of becoming limbless?

• Venum
• Cranial kinesis
• Can burrow

How many different kinds of crocodilians are there? What might explain the fact that there are so many more species of crocodiles than alligators?

• 13 species
• Higher distribution

One of the two species of extant alligators lives in North America while the other lives in

China. What could explain this disjunct geographic distribution?

Like other archosaurs, crocodilians have a four-chambered heart with complete separation of left and right ventricles. And yet, like turtles and other ectotherms, crocodilians need a right-to-left shunt in their circulatory system and have evolved a unique mechanism to achieve this. What does this suggest about thermoregulation in the ancestor of modern crocodiles?

• Suggests that ancenstors were endothermic

Crocodilians and birds share similar modes of reproduction. Describe this mode. what

does this allow us to infer about the reproductive modes of extinct dinosaurs? Why?

• Internal fertilization
• Males have a single penis - oviparous
• Nests, parental care, and vocalizations
  • Babies vocalize out of nest
• Dinosaurs would have inherited parental care and vocal communication 

Who were the pterosaurs, and what is their significance? How do they compare

ecologically and morphologically with other aerial vertebrates?

• The first group of flying archosaurs
• Diversity in skull structure - feeding specialization
• Fourth finger is elongated
• Long tail for steering
• Comparison
  • Both had hollow bones for light weight
  • Well developed sternum in pterosaurs
  • Pterosaurs have teeth
  • Pterosaurs in costal areas, birds inland

What is a “dinosaur”? Why might this term be misleading? Who were the two main

groups of ‘dinosaurs’ and how do they differ from one another?

• Dominant group of terrestrial vertebrates during the Mesozoic
• Two independent radiations, although they are grouped together and called dinosaurs
• Ornithischians
  • Primarily herbivores
  • Ancestral bipedialism -> secondary quadrupedalism
  • Pelvis - anterior projection of pubis that ran parallel to and projected beyong anterior part of ilium
  • Had cheeks and horny beaks rather than teeth
• Saurischians - two lineages
  • Herbivores -> 2ndary quad
  • Bipedal carnivores
  • Elongation of mobile S-shaped neck
  • Modifications of hand, skull, and post cranial skeleton

What are the skeletal features shared by all archosaurs, including the so-called

dinosaurs?

• Skull
  • Antorbital fenestra
  • Triagular shaped orbit
  • Laterally compressed teeth
• Femur
  • Fourth trochanter on femur
• Locomotion
  • Trend towards bipedalism
• Cuadofemoral muscles inserts on base of tail

What is the relationship between geology and dinosaur biodiversity during the

Mesozoic?

• Continents were still broadly connected
• Dinosaur faunas were quite similar
• Geographic separation after continents split allowed for regional differences - high diversity

• Were quite fast
• Combined lightness (hollow bones) with great strength

What are birds and where did they come from? Who are they related to? How do we

know this?

• Appear to most closely be related to a group of therapods called dromeosaurs
• Know using cladistic symstematics

What changes in structure and function were involved in the evolution of birds from a

theropod ancestor? What are the main derived features of birds? what distinguishes a “true

bird” from a dromeosaur dinosaur?

• Expansions for flight
  • Wrist structure allows wrist to be flexed and rotated sideways for seizing prey
  • Specialized shoulder joint allowing arms to be lifted upward and backward 
  • Larger sternum
  • Scales to feathers
• Derived features
  • Elongage S-shaped neck
  • Single occipital condyle
  • Intertarsal ankle joint
  • Tridactyl foot
  • Fused bony sternum
  • Reduced genome size
• Feathers and arrangement of flight feathers - how to distinguish a "true bird"

How would you respond to the comment that birds could not possibly have evolved

through gradual evolution since what good are feathers unless you can fly? What was the

original function of feathers?

• Feathers for thermoregulation, waterproofing, or communication

• Originated from scales
• Elongation of feather follicle precurser
• Flat surface that is asymmetrical about central shaft
• Asymmetric vaned feathers are needed for flight
• Symmetric vaned feathers are needed for thermoregulation

• Dark meat - muscle with high myoglobin content (high aerobid metabolism)
• White meat - muscle with low myglobin content

• Wing loading - weight of bird divided by surface area of wings
• Smaller body size

How is wing shape and feather organization related to life style/ecology in birds? give some examples.

• Four types of bird wings
  • Dynamic soaring - Shearwater, albatrosses
    • Lack slots in outer primaries, need wind gradient
  • High aspect ratio (fast flyers) - Swallow, swifts
    • Diving birds, aerial foragers, wings have flat profile and lack slots in outer primaries
  • Elliptical (maneuverable) - Pheasant
    • Low aspect ratio, live in forests and woodlands (need to maneuver), high degree of slotting in outer primaries
  • Slotted high lift - (static soaring) - Rough-legged hawk, eagle
    • Intermediate aspect ratio, deep chamber, marked slotting in primaries

How are foot morphology and beak morphology related to life style/ecology? Give some

examples.

• Feet
  • Longer legs to run faster
  • Reduction in number and length of toes makes foor smaller - faster (ostrich)
  • Webbed or lobed feet to swim
• Beaks
  • Horny beak in place of teeth
  • Can have short, thin, pointed bills for seizing insects (warblers)
  • Short, weak beaks and a wide gape (swallows)
  • Flattened bills with broad tips (spoonbills)

• Crop - enlarged portion of the esaphagus specialized for food storage - transportaion of food for nestlings
• Gizzard - food storage while chemical digestion continues, mechanical processing of food (squeeze contents, help grind food)

How do the lungs of an archosaur compare to those of a mammal? How do birds

maintain a one-way flow of air through their lungs?

• Alveolar lung - archosaurs
  • One-way flow of air through lungs
  • Complex system of air sacs that create a through-flow passage of air in the lung
  • Two groups of air sacs, anterior and posterior, occupy dorsal part of body and extend into cavities - poorly vascularized
  • Air flow and blood pass in opposite directions - crosscurrent exchange system - air sacs make this possible
• Alveolar lung - mammals

• Optic lobes are large
• Birds used most of their brains for complex behariors, rather than instinctive behavior

Most birds do not have a male copulatory organ, and yet fertilization is internal (as it must be, since the eggs are covered by a hard shell). How is this accomplished?

• Cloacal kisses
• Touch cloacas together and sperm is transfered from male to female

What explains the extensive sexual dimorphism between males and females seen in

many bird s(e.g. peacocks)?

• Highly colored males, with large plumage, vocalizations, and visual displays are more likely to find mates
• Females select for these types of males
• Sexual selection

• Altricial - young after hatched are relatively immobile and must be cared for
• Precocial - young after hatched are mobile and can defend themselves

What is the evidence that birds use an internal clock (circadian rhythm) for

determining when to migrate.

• Birds navigate quickly and easily on sunny days
• Navigate not quite as well on cloudy days
• Birds use visual clues (position of the sun) to navigate
• Day length is an important clue

What is the evidence that birds use visual cues (position of the sun) in order to navigate

during migration? What do they do on cloudy days? How do we know this?

Name some Orders of birds and give some examples. (Orders of birds end in “—

formes”, e.g. Columbiformes, Falconiformes.

• Struthioniformes - ostriches
• Galliformes - chickens
• Anseriformes - ducks
• Psittaciforms - parrots
• Falconiformes - falcons

• Mammals
• Presence of lower temporal fenestra 
• Endotherms
• Alveolar lung

Mammals are often thought to be more derived (or “highly evolved”) than “reptiles”.

does the fossil record support this idea?

• More active
• Constant metabolic rate
• Locomotory specializations
• Feeding specializations
• Limbs and girdles show changes in muscles, long bones, joing remodeling, and differentiation

• Pelycosaurs
• Therapsids

• Size of temporal fenestra
• Zygomatic arch
• Lower jaw and jaw joint/middle ear
• Teeth
• Bony secondary palate
• Loss of parietal foramen
• Position of limbs
• Shape of limb girdles
• Shape of feet
• Vertebral column
• Diaphragm
• Tail

How are the middle ear bones of mammals related to synapsid jaw evolution? What are

these bones?

• Jaw bones became ear bones
• articular ->Incus, quadrate -> malleus

• Allows breathing and eating at the same time

• Muscular, thoracic diaphragm
• 2 occipital condyles
• Four-chambered heart with left aortic arch
• Endothermy
• Single bone in lower jaw
• Heterodonty
• Incus and malleus
• Zygomatic arch
• Sweat glands
• Mammary glands
• Hair

*What is heterodonty? Diphyotonty? Identify the different kinds of teeth in a mammal

and describe their function. What is a tribosphenic molar? Give some examples of

specialized teeth in different groups of mammals.

• Heterodonty - specialized tooth morphologies
• Diphyodonty - juvenile vs. adult dentition
• Incisors (ripping), canines (tearing), premolars (grinding), molars (grinding)
• Tribosphenic molar - three cusped molar

How are the distinguishing features of mammals functionally related? give some

examples.

• Endothermy requires efficient circulatory system and insulation, and allows a big brain (high metabolic cost...inefficiencies)
• Sets up selection pressures for feeding specializations in jaws and teeth
• Sets up selection for locomotory specializations (running)

Show how the three main jaw muscles (temporalis, masseter, pterygoideus) work in

a mammal. How do the jaws and jaw muscles differ between carnivores/generalists and

herbivores? How are these differences related to functional differences (e.g. between a

herbivore and a carnivore)?

• Temporalis - up and down
• Masseter - sideways
• Pyerygoideus - sideways
• Carnivores - jaw joint at same level as tooth row
• Herbivore - jaw joint above level of tooth row; grinding teeth

Name and describe the three modern groups of living mammals and give some

examples. How do they differ from each other?

• Prototheria - (monotremes) 
  • Single hole - cloaca
  • Lay reptile-like eggs
  • Mammary glands but no nipples
  • Toothless, low body temp
  • Playypus, echidnas
• Metatheria - (marsupials)
  • Opossums, kangaroos, wombats
  • No true placenta, 2 uteri
  • End of penis is forked
  • Penis is located behind scrotum
• Eutheria - (true placentals)
  • True placentals
  • Humans, gorillas, dogs

*Why is it difficult to understand the phylogenetic relationships among modern

mammalian groups (es. the Eutherians)?

In terms of number of species, which group of placental mammals is the most

successful? Which is the second most successful? What could explain this fact?

• Rodentia (most) - reproduce so quickly, small amount of care for young
• Chiroptera (second) - bats 

Why do you think there are fewer species of mammals than there are of squamates,

birds, or even of frogs?

• Altricial young, longer gestation

What are some reproductive peculiarities of marsupials? Do you think these may have

made marsupials less competitive than eutherian mammals wherever they came into

contact? Can you think of any exceptions?

• Skin pouch on abdomen
• Body temp 22-26C
• Mammary glands and nipples
• No true placenta
• 2 uteri
• Double vagina
• End of penis forked
• Penis located behind scrotum
• Kangaroos!

What was the Great American Interchange? When were the first major human-caused

extinctions?

• South American was Isolated from North America until Pliocene when Panamanian land bridge was established
• Interchange of animals from N.A. to S.A.

• Lipotyphla - shrews, holes, hedgehogs
• Chiroptera - bats
• Carnivora - racoons, pandas, wolves
• Artiodactyla - cows, moose
• Perissodactyla - horses, rhinos, zebras

• Horns are made from keratin
• Antlers are true bone and are an extension of the animals skull

Why are ungulates often considered to be among the most derived of all

mammals?

• Single toe - hoof
• Fused radius and ulna - can't rotate forelimb
• Reduced canine teeth
• Bunodont molars
• Astragalus

• Soften plant based food with first stomach
• Regurgitate it, and then digest it again
• Regurgitated food is known as the cud

How does the fossil record of cetaceans contradict one of the main criticisms of

evolution by Creationists that intermediate fossils do not exist?

• Variety of intermediate forms of several species
• Fossil record shows that plethora of intermediate forms

What makes the Great Ape Family Paraphyletic? What is a solution to this problem? Do

you agree with it?

• Humans are placed in family Hominidae rather than Pongidae - this creates paraphyly because it is a group that consists of all of the descendents of a common ancester except one - humans
• Solution - apes were placed in homindae and pondidae became a subfamily

• Orangutans
• Gorillas
• Chimpanzees

How might heterochrony (e.g. Neoteny) have been involved in the evolution for humans

from an ape-like ancestor?

• Chimp fetus brain starts at same developmental stage and develops at same rate but human fetuses continue developing after chimps stop
• Humans resemble juveneille chimps - pedomorphism