Final test Flashcards
zygapophyses
interlock and prevent bending and twisting, and facilitates
transfer of weight to limbs
zygapophyses are found on
Vertebrae
Axial muscles have ___ main roles
2.
1. Postural support of the axial skeleton
2. Ventilation
axial muscles are Also important for locomotion by…
- Lateral bending in salamanders, lepidosaurs,
crocodylians - Dorsoventral flexion in mammals
- Powering of the tail in aquatic mammals
Appendicular Skeleton Includes
limbs & limb girdles (pectoral and pelvic)
Limb girdles of _____ are not attached to vertebral column.
Not suitable for life on land
fish
Tetrapod limbs are derived from
the fin of fishes
Tetrapods have _____ limbs including…
jointed limbs with wrist/ankle joints, hands, feet
and digits
Pelvic girdle made up of three paired bones
- Ilium
- Ischium
- Pubis
how is the pelvic girdle attached to the vertebral column
via the ilia
how is the pectoral girdle articulated with the vertebral column
indirectly, this provides greater ROM
Are larger animals simply an enlargement of smaller
animals? why or why not?
No, organism shapes change with size because:
– When a linear feature doubles in length:
* Surface area increases fourfold
* Volume increases eightfold
Allometry:
study of scaling.
The ancestral form of quadrupedal locomotion was
lateral axial movements with synchronized movement of diagonal pairs of legs
Amniotes use a “walk” gait
where legs move independently in succession
Can be sped up to the amble and trot
Mammals have fast gaits bound & gallop
tounge of terrestrial vertebrates is
muscular and use to manipulate food and aid in swallowing
Salivary glands provide
lubrication to help with swallowing and have enzymes to aid digestion
some are venomous
Breathing air may be ______ costly than
respiration in water
less
Amniotes use ________ aspiration
pump
negative-pressure
negative-pressure aspiration pump mechanism
Muscular expansion of the rib cage creates negative pressure that draws air inwards
Exhalation via elastic return of the rib cage to resting position
Amphibians have _____ lungs with ____
internal divisions
simple, few
Amniotes have _____ lungs with
_____ divisions which…
Complex, multiple
increases surface area for gas exchange
Adaptations to combat gravity when transporting blood
(1) higher blood pressure &
(2) valves in the veins to prevent backflow
Gas exchange with tissues occurs in
capillaries
Capillaries are
thin-walled and ‘leaky’
plasma is forced out of the vessels by high blood pressure. (returned by the lymphatic system)
Tetrapods have a _____ ______ cardiovascular system
double circuit
There is a ____ ____ present in all amniote hearts, but
its form varies
ventricular septum
types of ventricular septums
– A transient septum forms in turtles & lepidosaurs
– Permanent ventricular separation in crocs, birds andmammals
– Amphibians have no ventricular division
Coronary arteries are needed in
birds and mammals
because they have thicker ventricles and must work harder
Vision is _____ effective in air than water because….
more
light travels with less disturbance in air
The cornea of tetrapods focus light onto the retina with …
flatter lenses
how is the mechanism to focus light with the lens is different
between fish and tetrapods
– Fish move the lens
– Tetrapods change the shape of the lens (Except snakes)
Airborne sounds are transferred through a
bone or chain of bones in a middle ear
Middle ear is a
sound amplifier
mechanism of hearing
receive sound waves via the eardrum (tympanum),
Transfers to the oval window of the otic capsule via bone(s) movement of the oval window
transfers to movements of fluid in the inner ear
Stimulates hair cells in the organ of Corti within the lagena
ears of Sauropsid versus mammals
Sauropsids have one ear bone and a more superficial tympanum
Mammals have 3 ear bones and a deeper tympanum
how do amniotes reduce water loss
layers of keratinized epidermal cells which also protect it from wear
the skin has lipids which also reduce water loss (more effective)
amphibians skin is ___ ___ to water
Highly permeable
how is water lost
evaporates from the body’s surface via respiration and through the kidneys and feces
urinary bladder function
recovers water from the urine.
On land, temperature can vary _______ over short
distances, and can change ______
considerably, rapidly.
Heat capacity of water is ______ than air
Higher
how is thermoregulation accomplished
ectothermy and/or endothermy
Ectothermy
regulating body temperature by balancing the
movement of heat between an organism and its environment
Ectothermy is the Primary means of thermoregulation for
non-amniotes, turtles, lepidosaurs and crocodilians
Mechanisms of ectothermy include:
solar radiation, thermal radiation, convection, conduction, evaporation
Endothermy
Is the metabolic (chemical) generation of heat
Primary means of thermoregulation by birds and mammals.
Endotherms typically have _____ higher metabolism
than similar-sized ectotherms.
7-10X
Three Orders of Amphibians
Urodela (salamanders)
Anurans (frogs)
Gymnophiona (caecilians)
Extant Amphibian Characteristics
- Well-developed limbs
Except caecilians and some salamanders
Salamanders have tails, and caecilians have short tails and frogs do not have a tail in adulthood - Moist, permeable skin which contains mucus glands
cutaneous gas exchange
poison (granular) glands - Are Carnivorous
- Operculum-columella middle ear bones
- Green rod cells in the retina
Amphibian Characteristics-
swimming
- Salamanders and
caecilians swim by
passing a sine
wave down the
body - Anurans thrust the
hind legs
Amphibians: 1. Salamanders
- Order Urodela
- Elongated body shape with four functional limbs
- Move with walking-trot gait
- Almost entirely limited to the northern hemisphere
- Paedomorphosis is widespread
- Many go through an aquatic larvae stage & lose gills during metamorphosis
- Interestingly, one species-rich family of Plethodontidae is lungless
Salamanders -
Plethodontidae
Many use tongue to capture prey
– The Bolitoglossine plethodontids
– Have binocular vision
Amphibians: 2. Anura (frogs)
all continents except Antarctica
Skeletal system adapted for jumping
Anura Skeletal adaptations:
- Elongated hindlimbs
- Fused tibia and fibula
- Elongated ilium
- Urostyle
- Few presacral vertebrae
that are fused. - Strong flexible pectoral
girdle - Also have binocular vision
Anura Prey capture:
- Aquatic species use suction to engulf food
- Terrestrial and semi- aquatic species have long tongues that can be flipped out to capture prey
Amphibians: 3. Caecilians
Order Gymnophiona
Legless, burrowing or aquatic amphibians of the tropics
Have no or greatly reduced eyes
Have dermal folds called annuli which gives a segmented appearance
Have dermal scales in the annuli
Have sensory tentacles between eye and nostril
Amphibian Reproduction
Varied
* Most amphibians lay eggs (in water or on land or they carry their eggs)
* Eggs may hatch into aquatic larvae or mini-adults.
* Others retain eggs internally and give birth to metamorphosed young
* Parental care can vary
Salamander Reproduction
Most salamanders exhibit internal fertilization
Males deposit a capsule of sperm
(spermatophore) supported by a gelatinous base
usualy oviparous rarely viviparous
* Most that breed in water lay eggs in water
Anuran Reproduction short
breeding may last only a few days due to transient aquatic habitats
Males & females arrive at the same time
“Explosive breeding
Anuran Reproduction Longer
breeding may last for several months
- Males arrive at the breeding site first and
defend territories - “Prolonged breeding”
Anuran Reproduction overall
diverse species specific Advertisement calls (vocalizations) is a
characteristic of anuran breeding
high Energy and exposure to predators
Females respond when eggs are ready to be laid
Most anurans reproduce via external fertilization (some internal)
Males grasps female as a part of the mating process: amplexus (froggy style ;)
Anurans- Tadpoles
very different from the adults.
As filter feeders, they can exploit ephemeral food resources not available to adults.
Anurans- Metamorphosis to adults
- Transition in body form from larva to adult
- Stimulated by the hormone thyroxine
Caecilian Reproduction
Internal fertilization
Males have a penis-like organ that is protruded from the cloaca
both oviparity and viviparity
Embryos of terrestrial species have filamentous gills
Embryos of aquatic species have sac-like gills
Gas and Water Exchange amphibians
- Amphibian skin is permeable to gases and water
- A significant portion of their gas exchange is cutaneous.
– Remaining is pulmonary respiration - Anurans rely more on lungs for oxygen uptake as temperature and their activity increases
Amphibians do not drink water, those living in aquatic environments need to overcome the continuous influx of water how do they do it?
– Do this by producing urine
– Terrestrial amphibians possess a specialized pelvic patch for water uptake
– Highly vascularized skin in pelvic region for water absorption
what does amniota represent as a group
-inner membrane in egg that protects the embryo (amnion)
-the membrane is derived from the embryo itself not from the mother
what are amniotes divided into
- Sauropsida: birds, crocodiles, turtles, reptilians and tuatara
– Extinct taxa include dinosaurs & pterosaurs (first group capable of flight) - Synapsida –> mammals
– Extinct taxa include pelycosaurs and therapsids
sauropsid and synapsid linages
- Synapsid and sauropsid lineages separated before many derived characters associated with terrestrial life emerged.
- Therefore, the lineages independently developed many derived adaptations including endothermy, parental care and social behaviours
- They also evolved different solutions to other selection pressures:
1. Locomotion & Respiration
2. Uptake of oxygen and release of carbon dioxide (i.e., gas exchange)
3. Waste excretion that conserves water (water is a limiting resource)
locomotion and respiration of sauropsids (early)
- Early tetrapods had short limbs, sprawling posture and long tails
-lizard walk - lungs decrease and increase in volume based on walking because of side to side motion
locomotion and respiration of synapsids
- Upright posture with limbs more underneath the trunk
-legs move independent of trunk
-no affect on respiration - Diaphragm
- Bounding gait
- Trunk vertebrae differentiated into thoracic and lumbar
bipedal locomotion and respiration of sauropsids
Do not have a diaphragm, instead:
– pelvic movements
– ventral ribs (gastralia)
gas exchange in tetrapods
- To support higher levels of muscle activity associated with tetrapod evolution, more gas exchange was needed
– Therefore, more surface area
– Sauropsid and synapsids developed complex lungs but lung morphology varied. - i.e., evolved different solutions to the same problem.
different structures of lungs
A. Lissamphibia
-simple sacs with tidal flow
-lung contains mixture of freshly inhales air and from previous breaths
B. alveolar lungs of mammals
-we both know how these work
C. Faveolar lungs of sauropsids
-air passages connected by many parabronchi with falveoli in their walls
-gas exchange occurs at falveoli
-air flow is unidirectional
-fresh air flows in one direction through parabronchi and falveoli and blood flows in the opposite direction
Synapsid lungs
- An Alveolar Lung
- Air travels through the trachea to progressively smaller airways via the primary bronchi –> e.g. 23 levels of branching in the human
- Air ultimately reaches the alveolar sacs, which are the sites of gas exchange
- Tidal ventilation brings air into and out of the airways to the alveoli
- The alveoli can be re-inflated due to the production of surfactants –> reduce the surface tension of water lining the alveoli
bird respiration
Unique in 2 ways:
1. Have small tubules that radiate from parabronchi for gas exchange –> air capillaries
* Use crosscurrent exchange
2. Presence of air sacs
* Two groups –> anterior & posterior
* Not used for gas exchange –> act as bellows during respiratory cycle
- Birds require 2 respiratory cycles to pass 1 unit of air through the respiratory system
how is oxygen transported on land
- High blood pressure is important for circulation but can cause problems for gas exchange in the lungs.
- Solution: two blood circuits (pulmonary and systemic) created by a permanent septum in the ventricle (for most, not all)
– Most likely not seen in ancestral amniote
– Transient septum in turtles, lizards, snakes and tuatara
waste elimination
- ammonia (NH3), which is quite toxic, but soluble in water.
- Nitrogenous wastes are primarily excreted in urine.
- Terrestrial organisms need to deal with eliminating nitrogenous waste without losing much water
solution to waste elimination
- Synapsids excrete nitrogenous wastes as urea, which is more water soluble and less toxic.
- Mammalian kidneys are adapted to producing concentrated urine, thereby conserving water.
- Sauropsids produce uric acid which has low solubility in water and low toxicity.
– Combines with ions (e.g., potassium, sodium) in the cloaca or bladder and forms a precipitate.
– Water is reabsorbed and the precipitate expelled
sensory system of amniotes
- Sensory systems are diverse within and between synapsids and sauropsids
- Differences exist in vision, chemosensation and hearing
- Generally speaking:
– Synpasids rely more on olfaction than vision.
– Sauropsids have variable olfactory sensitivity but excellent vision (good depth perception)
Lepidosaurs- characteristics
largest non avian reptiles
Predominantly terrestrial
Scales cover the skin
outer layer of epidermis sheds at intervals
reduction or loss of limbs
transverse cloacal slit
2 orders of Lepidosaurs
- Rhynchocephalia- the tuatara
Only one extant species
- Squamata- the lizards and snakes
More than 10,000 species
Order Rhynchocephalia: Tuatara
The tuatara (“spines on the back”)
One extant species : Sphenodon punctatus
Only in New Zealand
Nocturnal animals that feed on invertebrates and small vertebrates (frogs, lizards, birds).
Low active body temperatures
Live in burrows
Squamates- lizards and snakes have ___ growth
Determinate growth- (eventually stop growing)
Lizards (suborder Lacertilia)
range in size and body forms
Snakes: suborder Serpentes
Probably evolved from a subterranean lineage of lizards
Range in size and body form
Snake Characteristics
forked toung
flexible skull
ovi/vivipours
some have temp dependant sex most are genetic
most have no parental care
turtle skeleton
Beta-keratin forms outer layer of horny scutes
Inside is lateral extension of ribs
Limbs inside ribs
males have concave plastron (turtle style ;))
2 types of turtles
Cryptodires “hidden neck” (wide distribution, 11 families)
Pleurodires “side neck” (3 families, S Hemisphere)
Turtle Respiration
Turtle ribs are fused to the shell so the Lungs attach to the carapace dorsally & laterally
expansion restricted by carapace
adjust lung volume with muscles that change gut position.
some species use cloacal or pharyngeal respiration
Pharyngeal respiration-
when confined underwater they draw water into mouth and pharynx. Have highly vascularized papillae
Cloacal respiration
in at least one species, the cloaca is lined with sacs with highly vascularized lining. Turtles pump water into and out of cloacal sacs.
Turtle- other characteristics
incomplete septum between the ventricles of heart (Flow of blood is controlled partly by the relative resistance to flow in each circuit.)
endothermy and ectothermy
oviparous with internal fertilization
Temperature dependent sex determination
Little parental care
aligator teeth and integmentary sensors
when mouth closed only see upper teeth
sensors only on head
crocodile teeth and integumentary sensors
all teeth visible when mouth is closed
sensors on whole body
Gharial head teeth and integumentary sensors
long snout
all teeth visible (mandibular synthesis on the 20th row
sensors on whole body
False gharial head teeth and integumentary sensors
long snout
all teeth, ( mandibular fused at 16th row)
sensors on whole body
Crocodylians: Other Characteristics
All are oviparous with hard-shelled eggs laid in a nest guarded by the female
Temperature-dependent sex determination
Predators
The most ancestral birds
Center of gravity shifted to wings
Tail, including the pygostyle
Skeletal features for flight
Claw size
Larger sternum
Dietary specializations
Birds
flight
Mostly diurnal
Have excellent vision
flight adaptation 1 Streamlining and weight reduction
Streamlining of feathers and feet
Weight reduction adaptations include:
lack urinary bladders,
have one ovary and males lack a phallus and gonads regress after the breeding season
Skeletal features…
adaptations for birds flight 2: Skeleton
same skeletal weight: body weight ratio as mammals
different distribution: leg bones are heavier and skull is lighter in birds
more rigid on thee periphery of bones
Center of gravity is beneath the wings
Large keeled sternum
Reduction in number
fusion of bones
pneumatosized bones
Elongated pelvic girdle: ischium & ilium are thin sheets and attached with a synsacrum
Tail is shortened to ~5 caudal vertebrae that ends in the pygostyle
birds adaptations for flight 3: muscles
Major flight muscles are:
Pectoralis major
Supracoracoideus (up stroke)
Leg muscle mass varies with lifestyle
birds Reproduction
Exclusively oviparous
Genetic sex determination
Class Mammalia: Characteristics
Relatively low species richness
largest body size
Lactation
Hair
Three middle ear bones
Red blood cells without nucleus
Mammal Taxonomy
Allotheria: extinct multituberculates
Prototheria: monotremes
Theria: includes metatheria & eutheria
Allotheria
Lived during the Late Jurassic to early Cenozoic
Broad multi-cusped molars
Viviparous
Herbivorous or omnivorous
Terrestrial or arboreal
Prototheria: The Monotremes (echidnas)
Cloaca: Have a single opening for excretory and reproductive functions
Lay eggs, leathery shell
No nipples, milk patch on the abdomen
No teeth
Electro-sensors on bill
Metatheria: The Marsupials
Metatheria: The Marsupials
Mammals Sex determination
Mammals have distinctive sex chromosomes X and Y
Males are heterogametic: XY
Females are homogametic: XX
Except for the platypus which has 5 sex chromosomes
bird feather types
contour feathers: flight
secondary plumes: flight and insulation
Downey feathers, insulation
geckos are ____ other lizards are ____
nocturnal
diurnal
phosorial
underground
zygodactylus
joining toes
