Exam 3 Flashcards
What organisms are considered primitive Actinopterygii?
bicher and chondrostei (paddlefish & sturgeon)
What is the group Neopterygii known as?
modern ray-finned fishes
What are the 2 groups of Neopterygiians?
primitive & teleostei
What 2 groups of primitive Neopterygiians still exist?
the gars and the bowfin
What group of fish were abundant in the middle of the Mesozoic Era, but then most went extinct by the end of the same era?
primitive neopterygii
What kind of skeleton & scales do primitive neopterygiian fish have?
bony skeletons and ganoid/cycloid scales
What kind of gas bladder do primitive neopterygiian fish have?
they are physostomes (gas bladder that functions as an accessory lung)
What kind of digestive tract and tail do primitive neopterygiian fish have?
digestive tract with a spiral valve and abbreviated heterocercal tail
How many species of gar are there?
7
Describe a gar’s body.
long body with long snout (jaws); snout varies based on species
What does the gar’s body shape allow for?
quick acceleration
What kind of scales does a gar have?
ganoid scales
What does a gar feed on?
it is carnivorous and feeds on other fishes
What kind of teeth does a gar have?
sharp needlelike teeth
How do gars catch their prey?
they are camouflaged; wait quietly for fish to approach & then quickly accelerate and strike rapidly
In what environments are gar found?
rivers, lakes, estuaries & occasionally coastal waters
What coastal waters are gars found in?
eastern north America, Central America, and the Caribbean
Where are gars found in AL?
rivers, lakes, and bays
What is an example of the diversity seen in gars?
the alligator gar
Describe an alligator gar.
largest of the gars
name is due to its alligator like snout and mouth
Where do alligator gars live?
bays, estuaries, coastal waters and travels up rivers
How large can alligator gars grow to be?
3 m (9.8 ft) and 137 Kg (300 lbs)
What is the largest recorded freshwater alligator gar found in AL?
over 150 lbs
How many species of bowfins are there?
1
What are the common names of the bowfin fish?
grinnal, mudfish, dogfish, cotton fish
What is the body of a bowfin covered in?
head is covered in bony plates, body is covered in cycloid scales
How large can a bowfin get?
2 ft and 20 lbs
Where are bowfin found?
lakes, streams, and they thrive in swamps
What places are bowfins found?
eastern & southeastern America including alabama
Where were 8500 lbs of bowfin caught in a single year?
lower tombigbee & mobile delta area of alabama
Why are bowfin fish usually called “trash fish”?
they are not good to eat
What do bowfin feed on?
they are carnivores and feed on other fish
What are bowfin used for in some areas of the southeast U.S.?
their egg; “bowfin caviar” or “cajun caviar”
What group of fish are the most advanced and specialized bony fishes?
teleostei
When did teleost fish first appear in the fossil record?
triassic period
When did teleost fish become abundant?
by the end of the cretaceous
How many living species of teleosts are there?
over 26,000 (96% of living fish species)
What percentage of all vertebrate species do teleosts account for?
40%
What kind of scales do teleost fish have?
cycloid or ctenoid scales
What kind of gas bladders do teleosts have?
most have bladder specialized for buoyancy control & most are physoclists
What kind of tails do teleosts have?
homocercal
How are teleosts the most highly diverse group of fish?
diverse in size, shape, habitat, feeding style, behavior, & reproduction
How has the diversity affected the teleosts?
allowed them to adapt to a wide variety of niches in the aquatic environment
How does shape vary in teleosts?
depends on ecology & behavior of the fish
What are fusiform shaped fish specialized for?
fast prolonged cruising; the body shape decreases resistance to water when cruising
How fast can dolphin fish (mahi mahi) accelerate?
35 mph
How fast can tuna accelerate?
40-50 mph
How fast can a swordfish accelerate?
60 mph
What are long, thin & streamlined body shapes specialized for?
acceleration
What are examples of fish with long, thin, and streamlined bodies?
pike
barracuda
What is a compressed body shape (laterally compressed) used for?
they are normally slow but they are good at maneuvering
How do fish with a compressed body shape confuse predators?
they silhouette changes drastically with change of direction
What are examples of fish with compressed body shapes?
angelfish
butterfly fish
flounder
How are flounders different from other compressed fish?
both eyes are on one side of the body
shape allows them to blend in with the bottom
they continually change color to match the background
What does a depressed body shape (dorsal/ventral depression) help with?
helps some species blend in with the bottom
What are examples of depressed fish?
scorpion fish
anglerfish
How do depressed fish catch their prey?
lay on bottom & wait for prey to approach
Since most fish are intermediate with the depressed body shape, how good are their movements?
they are moderately good at all 3 types of movements
What are the 3 different types of movement can a fish do?
cruising
acceleration
maneuvering
What fish show extreme specialization of fins?
mudskipper
flying fish
How do mudskippers “walk” out of the water?
using heir strong specialized pectoral fins
Do mudskipper’s eyes focus better in the air or in water?
in the air
Why is a mudskipper’s skin and mouth highly vascularized?
for oxygen exchange
How long can a mudskipper live outside of the water?
up to 30 hours
Where do mudskippers inhabit and what do they feed on?
inhabit the shoreline; feed on algae, insects, marine invertebrates, etc.
What is an example of a fish similar to the mudskipper?
leaping blenny from the south pacific
How does the flying fish glide through the air?
use their pectoral fins as wings
How do flying fish get out of the water in order to glide?
use their tail fin to accelerate and propel themselves out of the water
How far can a flying fish glide for?
90 m (300 ft) or more
Define simultaneous hermaphrodite.
both sexes at the same time
Define sequential hermaphrodites.
changes sex during lifetime
Are there some teleosts that are hermaphrodites?
yes
Define protogynous;
females to males
What is an example of a protogynous fish?
bluehead wrasse
Define protandrous.
males to females
What is an example of a protandrous fish?
anemone fish
Most teleosts lay eggs and use external fertilization, but some are _______.
live-bearing (guppies)
How do seahorses reproduce?
female deposits eggs in males “brood pouch” and the fish hatch in the brood pouch
How many species of freshwater fish does alabama have?
300 species
Why does alabama and Tennessee have so many freshwater fish species?
due to the diverse geographic regions and abundance of rivers and lakes
When do the first amphibian like tetrapods appear in the fossil record?
in the Devonian: “age of fishes”
What was present in the Devonian period?
fish were abundant and the terrestrial environment had plants, trees, and invertebrates
What are the possible advantages (selective pressures) of being able to survive on land?
food availability
avoidance of competition
avoidance of predators
survival during dry seasons
Was the terrestrial environment initially predator free for vertebrates?
yes
What are the major changes seen in amphibians that reflect their adaptation to the terrestrial environment?
efficient lungs
well developed limbs for terrestrial movement
shift in sense organs
What did most terrestrial forms of amphibians lose?
lateral line system
electric sensors & organs
What senses increases for amphibians?
hearing and vision
What extinct group of fish were very structurally similar to amphibians?
osteolepiforms a group of sarcoptrygiian fish (subgroup of rhipidistia)
What are similar characteristics between amphibians and the osteolepiforms?
well developed lobed fins with homologous bones
fin structure
bony skeleton
skull similarities
similar tooth structure ( sharp and sturdy)
What are the early amphibian like tetrapods also known as?
non amniotic tetrapods
What vertebrates are amniotic?
reptiles, birds, and mammals
When are the earliest fossils of tetrapods found and what are they associated with?
late Devonian; they are associated with freshwater
What were Ichthyostega and Acanthostega?
two of the earlier tetrapods
How big were Ichthyostega and Acanthostega?
0.5-1.0 m in length
Ichthyostega had characteristics of what?
osteolepiform fish and amphibians
What are the characteristics of Ichthyostega?
caudal fin on tail supported by bone & ray
scales on tail
internal gills (and lungs)
operculum
sharp sturdy teeth
advanced vertebral column
well developed limbs & girdle
distinct “neck” & elongated snout
Do tetrapods immediately radiate?
no
When did tetrapods begin to radiate?
mid carboniferous period (30 million years after appearance)
When did amphibian like tetrapods rule the terrestrial environment?
mid to late carboniferous period
What are some characteristics of the amphibian like tetrapods that ruled the terrestrial environment?
probably stayed close to water while some were primarily aquatic
some were stocky, short legged, heavy bodied, and large headed
What is an example of a stocky, short headed amphibian like tetrapod?
eryops, could grow to 2 m or more in length (6.5)
What was the largest of early amphibian like tetrapods?
mastodonsaurus (4 m or 13 ft in length)
When did the Mastodonsaurus occur?
start of the mesozoic era
When was there a decline in the number of amphibian like tetrapod species?
mid to late permian period
Was there a time when reptiles were increasing and may have out competed many of the early amphibian like tetrapods?
yes
What was the result of environmental conditions being harsh during the late permian?
mass extinctions (permian/triassic extinction)
When do the first fossil frogs and salamanders date back to in the fossil record?
jurassic period (mid mesozoic era)
What are the 3 groups (orders) of amphibians that have survived to present day?
Anura
caudata
apoda
What organisms are in the order Anura?
frogs and toads
What does Anura mean?
without tail
What organisms are in the order Caudata?
salamanders and newts
What does Caudata mean?
tailed
What organisms are in the order Apoda?
legless burrowing amphibians
What are Apoda commonly known as?
caecilians
What does Apoda mean?
no limbs
What does Caecilian refer to?
blind
What are the characteristics of amphibian skin?
no scales
smooth, moist, permeable to water
How can amphibians lose water through their skin?
evaporation
Why is the skin very important for respiration in amphibians?
primary site of gas exchange because of the thin epidermis and well vascularized dermis
What is an example of why the skin is the primary site of gas exchange in amphibians?
some adult salamanders have no lungs or gills
What does the epidermis molting do for amphibians?
allows for growth and new outer layer of skin for optimal respiration and protection
What does the skins dermis of an amphibian contain?
contains glands and chromatophores
What do mucous glands do in amphibians?
help waterproof skin and prevents desiccation, also helps prevent infection
What do poison glands do for amphibians?
produces watery poisons that prevent predation, some amphibians have very toxic poison
What does the rough skinned newt or Californian newt secrete?
tetrodotoxin (TTX)
What is TTX?
very poisonous toxin that acts by blocking Na+ channels in cell membranes
Does the red spotted newt also produce TTX?
yes
What does the poison arrow frog secrete?
batrachotoxin
What does batrachotoxin do?
extremely toxic, opens Na+ channels in the cell membranes
Can batrachotoxin be lethal to humans?
yes, if it enters an open wound and gets into the blood
Where are poison arrow frogs found?
central and south America
What is batrachotoxin used for historically?
used on the tips of hunting arrows/darts by South American natives
What do can frogs secrete?
bufotoxin
What is bufotoxin?
contains a variety of substances that can be toxic to pets and humans; on toxin is a serotonin agonist and appears to be hallucinogenic
When are gills present in amphibians?
during larval development/larval stage
Are gills normally internal or external in amphibians?
normally external
How are the gills gotten rid of in amphibians?
they usually degenerate during metamorphosis
Do some amphibians retain gills throughout life?
yes
How is most carbon dioxide removed from the body of amphibians?
via the skin
How do some salamanders (plethodontid salamanders) respire?
entirely through their skin and mouth because they lack both lungs and gills as an adult
Describe the lungs in salamanders.
composed of smooth walls
Describe lungs in frogs and toads.
numerous folds and alveoli to increase surface area and increased vascularization
Amphibians are positive pressure breathers, how does this work?
they pump air into lungs by a swallowing process; there is no diaphragm
What structure do many amphibians have that contains the vocal cords?
larynx
Salamanders and caecilians generally don’t vocalize, however then can do what?
produce squeaks or clicks by exhaling
Where is the larynx in frogs located?
upper end of trachea
How do frogs make sounds?
by passing air back and forth over vocal cords between lungs & 1 or 2 vocal sacs in the floor of the mouth
Male frogs make what kind of call to attract females and maintain territory?
advertisement calls
What other kinds of sounds do frogs produce?
warning sounds or screams
Describe a fishes circulatory system.
all blood entering the heart is deoxygenated and pumped to gills and then the body; no separation of oxygenated and deoxygenated blood
How many chambers does an amphibian heart have?
3 chambers, one ventricle and two atria
Where does deoxygenated blood enter the amphibian heart?
the right atrium
Where does oxygenated blood enter the amphibian heart?
the left atrium
What is the advantage of having 2 atria?
blood only partially mixes in ventricle
majority of deoxygenated blood goes to lungs
majority of oxygenated blood goes to body
What does a double circulation pattern increase?
the efficiency of the circulatory system
Adult amphibians are normally ______.
carnivorous; some larval amphibians are herbivores
What kind of feeders are frogs and toads?
sight feeders
Many amphibians have what that are attached to the front floor of the mouth?
well developed tongues
The free end of the tongue has glands that produce what?
sticky secretions
What does a frog/toads digestive system encompass?
stomach
small intestine
large intestine
cloaca
liver
pancreas
Are the cerebrum and cerebellum large or small and simple in amphibians?
small and simple
How many pairs of cranial nerves to amphibians have?
10
Where is the most activity in the brains of amphibians?
in the midbrain
What is the anterior portion of the brains of amphibians oriented to?
most olfactory oriented
What is the vomeronasal organ (VNO)?
accessory olfactory organ
Where is the VMO located?
in an invagination of nasal passage in some salamanders and on the floor of the nasal cavity in frogs
What is the VNO used for?
sense specific airborne molecules, in particular pheromones
What are pheromones?
chemicals released by one individual that influences the behavior or physiology of another individual
What is the VNO important for?
mate ID and triggering reproductive behaviors in some amphibians (many salamanders)
Is vision well developed in many amphibians?
yes, especially in frogs and toads
What is the retina specialized for in frogs and toads?
detecting movement of objects across the retina
Since frogs and toads contains rods and cones in the retina, what does this mean?
have both low light and color vision
Do amphibian eyes accommodate?
yes, they do this by moving the lens
What is the Harderian glands used for in amphibians?
located in the medial corned of the eye that produces oily secretions that lubricate the eyes
What do terrestrial forms of amphibians also have?
eyelids to cover and protect the eyes
What does the lower eyelid of amphibians contain?
nictitating membrane that can mover across and wash the eyes with secretions
Do some amphibians contain a pineal eye?
yes
Is the pineal eye important in seasonal cycles (reproduction)?
yes
Are frog and toad ears well developed?
yes
Since there is no external ear flap or canal, how do they hear?
they have large tympanic membranes and an ear bone in the middle ear
What is the single middle ear bone called?
columella; homologous to stapes in mammals
What does the columella do?
connects tympanic membrane to the inner ear
What is the ear used for in amphibians?
hear mating calls used in territorial behavior and mate ID, also alarm calls
Is hearing important to salamanders and caecilians?
no
Do salamanders and caecilians have a tympanic membrane?
no, but they do have inner eats and some have a columella
How many pairs of semicircular canals do amphibians have and what are they used for?
3 pairs; detecting movements and body position
Is the lateral line system present in larval and adult amphibians?
no only larval, however can be seen in adults
What is an example of an amphibian that retains its lateral line system into adulthood?
Xenopus (African clawed frog)
What does the amphibian endocrine system encompass?
hypothalamus
pituitary
thyroid
What does the thyroid gland produce in amphibians?
thyroxine which is important for stimulating metamorphosis and molting
Why do amphibians need a moist environment to reproduce?
because amphibians eggs are composed of embryo, yolk, and a jelly layer; they lack the protective membranes so without the moist environment they will dry out
What is metamorphosis in amphibians?
where they change from aquatic larval form to a more terrestrial adult form
What is metamorphosis stimulated by in amphibians?
the hormone thyroxine
Do some amphibians undergo metamorphosis iin the egg and hatch directly as adults?
yes (direct development)
How many living species are there from the 3 surviving groups of amphibian like tetrapods?
7000
What percentage of the 7000 species are frogs?
90%
What order are the caecilians?
Apoda
What are the Apoda?
limbless amphibians with reduced vision; able to only detect light from dark
What is the size range for Apoda?
10 cm to over a meter in length
Does Apoda lack both limbs and girdles?
yes
What is the lifestyle of Apoda?
most burrow, a few are aquatic
How does Apoda move?
worm like comments or by undulating their bodies form side to side
Can Apoda adults see?
they have small eyes and most adults are blind
What does Apoda feed on?
worms and small invertebrates
How many species of Apoda are there?
over 190
Where can Apoda be found?
tropical forests of central and South America, Africa, and Asia
How does Apoda reproduce?
utilize internal fertilization
What are the other variable aspects of Apoda reproduction?
deposit eggs in moist soil in burrow or near water
some produce aquatic larva that go through metamorphosis
some produce direct development
some bear live young
What organisms are part of Caudata (Urodela)?
salamanders, newts, sirens, amphiuma
How many species of Caudata are there?
650
Where does Caudata majorly occur?
northern hemisphere
How long can Japanese and Chinese giant salamanders get?
1.5 m or more
Describe Caudata limbs.
to the side of their body so they can move in an undulating fashion
Does Caudata have gills?
yes at some stage in life but most degenerate when they undergo metamorphosis
What do Caudata feed on?
small invertebrates; insects, worms, mollusks
What is an example of Caudata that produces tetrodotoxin?
rough skinned newt and red spotted newt
Do Caudata make sounds?
no
Do Caudata have tympanic membranes? If not what do they have?
no; they have inner ear and sometimes a middle ear bone, so they hear but not well
How long can Caudata live for?
many live for 10-20 years, but can live longer
What is the record life for a Japanese salamander?
52 years
Where does Caudata inhabit?
freshwater or moist terrestrial habitats
Can some Caudata live their entire life in an aquatic environment?
yes
Where else can Caudata live?
completely terrestrial and metamorphosis occurs in the egg
When and where does Caudata normally breed?
early spring in or near ponds, streams, and lakes
Do some Caudata have strong homing abilities when migrating to ponds?
yes
When does Caudata normally migrate?
first warm rainy nights of late winter/early spring
What do the courtship behaviors of Caudata look like?
visual cues like body movement (circling and tail wagging)
What else can courtship include?
chemical cues (pheromones)
How do male Caudata use their pheromones?
some have chin glands and other have cloaca glands which release pheromones that stimulate females
What is the sexual behavior of Caudata?
amplexus
Describe what happens after amplexus among Caudata.
male releases spermatophore and female picks it up with cloaca
female deposits eggs, often in groups
Where do some species of Caudata deposit their eggs?
moist leaves, logs, rocks, small holes, or burrow in moist mud
Do some species of salamanders exhibit parental care of eggs?
yes
What is the “egg”?
fertilized egg with gelatinous coat
What happens during metamorphosis in Caudata?
larva reabsorb gills, develop lungs, reabsorb fin on tail, eyelids develop, and take on adult coloration and body form
What is paedomorphosis also known as?
neoteny
What is neoteny?
maintaining larval characteristics into adulthood
When does sexual maturity develop?
in larval body form
What are the 2 types of paedomorphosis?
obligate and facultative
Describe obligate neoteny.
always retain larval form
can still undergo metamorphosis under certain conditions
What are examples of obligate neoteny animals?
mudpuppy and siren
Describe Axolotl.
pedomorphic species from a lake near mexico city that docent undergo metamorphosis
Describe facultative neoteny.
some undergo metamorphosis depending on the environment
some never undergo and remain larvae
others may undergo during dry periods
What is an example of a facultative paedomorphic species?
tiger salamander
Where is one of the best places to study salamanders?
southeastern U.S.
What is the most successful group of amphibians?
Anura (frogs and toads)
How many species of Anura are there?
6300
How big can Anura get?
1 cm to over 2 ft
Describe the body of Anura.
large strong hind limbs
short bodies
lack of tail (decreases weight)
What is jumping used for?
escaping predators, jumping towards prey, general movements
How do frogs feed?
carnivorous, sight feeders, and eat anything moving
What happens to frogs during the winter in cold climates?
hibernate at bottom of ponds or streams or in burrows; body build up glucose and urea which act as antifreeze
Describe male frogs after hibernation.
return to breeding pond/stream before females
occupy certain locations and become vocal
What kind of fertilization do frogs use?
external
How are frog eggs usually deposited and when do they hatch?
gelatinous mass; 2-30 days later tadpoles hatch
What do tadpoles feed on?
herbivorous and graze on plants or filter feed algae for approx 1-12 months
How long does metamorphosis take in tadpoles?
2-8 weeks
What happens during metamorphosis?
tail and gills are absorbed and legs and lungs develop
How long does it take a young frog to reach sexual maturity?
1-3 years
How long can many frogs live for?
10 years or more in captivity
What are examples of diversity in reproductive development in frogs?
lay eggs and leave in egg masses to hatch
some undergo metamorphosis in egg, direct development (seen in some salamanders and caecilians)
How many eggs release during amplexus?
200-500 in 10 min
Describe reptiles.
most primitive vertebrate that has fully adapted to a terrestrial environment
How can reptiles not require a moist or humid environment ro survive and reproduce?
amniotic egg (doesnt dry out)
watertight skin
What is another name for an amniotic egg?
cleidoic egg
Describe an amniotic egg.
has embryo & yolk (similar to amphibians)
also has several extra embryonic membranes and an egg shell that protects and prevents water loss
Describe amnion.
membranous sac that surrounds embryo
liquid filled and provides protection from dessication and injury
What is amniotic fluid somewhat similar to?
plasma
What is chorion?
fibrous protective membrane that surrounds entire internal portion of egg
What is the allantois?
membrane that collects waste
What is the fusion of the allantois and chorion responsible for?
highly vascularized and attach to the inside wall of the shell, responsible for respiration
Describe the yolk sac.
vascularized membrane that surrounds yolk
Describe the yolk.
proteins and lipids are picked up by blood and delivered to embryo; food supply for embryo and hatchling
What is the mineral layer of an egg used for?
calcium carbonate forms outer layer (amount of Ca+ can depend on species)
Describe the fibrous layer of the egg.
protein that forms the inner layer of the egg shell
What are the advantages of an amniotic egg?
prevents desiccation of embryo in terrestrial
prevents predation from aquatic organisms
Describe reptile skin.
forms a protective barrier between environment and organism
How is the outer layer of skin watertight in reptiles?
contains relatively large amounts of protein and lipids that help make it watertight
What is the origin of reptile scales?
epidermal
What is the outer layer of scales composed of in reptiles?
cornified epithelium (dead cells filled with keratin)
What does the epidermis do?
provides protection and prevents water loss
Describe molting.
periodic shedding of outer layer epidermis
occurs regularly in some reptiles
some reptiles shed in one piece
lizards shed in large pieces
some reptiles skin gradually wears off
What is the outer layer of the epidermis called?
stratum corneum
What animals molt in one piece?
snakes
In what animals does molting regularly occur in?
snakes, lizards
In what animals does the molt just wear off?
alligators and some turtles
Why do reptiles molt?
growth and replace worn scales
What does reptile skin normally lack?
skin glands
Describe the reptile skeleton.
more adapted for terrestrial existence
strong skeleton
better developed pelvic and pectoral girdles and limbs
provides better movability
Describe the legs or lizards and turtles.
sprawled to the side
Describe the legs of alligators and crocodiles.
partial rotation of limbs under body
What enhances in extinct groups of reptiles whose limbs are fully rotated under them?
enhances speed and agility
How do reptiles have better developed necks than amphibians?
multiple cervical along atlas and axis of neck bones, only has one occipital condyle
Why are reptile jaws and jaw muscles stronger than amphibians?
reptile jaws are adapted for gripping, crushing, and ripping tissue; allows more efficient feeding
Reptiles are the first vertebrate with what?
true cerebral cortex
Where is most reptile brain activity?
cerebrum, accompanied by a size increase
How many cranial nerves do reptiles have?
12
What animal has one of the most highly developed pineal gland of any vertebrate?
tuatara
What kind of heart do reptiles have?
3 chambered
What kind of heart do crocodilians have?
4 chambered heart
What does poikilothermic mean?
body temp varies with environmental temp and sunlight
What is an advantage to adapting to a terrestrial environment?
at times you can be warmed by the sun and increase metabolic rate, activity, etc
What is one exception to normal cold blooded reptiles?
leatherback sea turle
What organ in reptiles is more advanced and efficient than those in amphibians and fish?
the kidneys
Why can’t reptile kidneys concentrate urine?
the nephrons don’t have loops of Henle
Why do some reptiles have salt glands?
get rid of excess salt from the body
Where do marine iguanas, turtles, and crocodilians have salt glands?
iguanas- nasal
turtles- lacrimal in orbit of eye
crocodilians- under their tongue
What do the lungs of reptiles have more of in comparison to amphibians?
more surface area for respiration
What do most reptiles use to help expand and contract chest to inhale and exhale?
intercostal muscles attached to the ribs
Leg, body, and head movements can also help do what in some reptiles?
ventilate lungs
What kind of breathers are reptiles?
negative pressure breathers
Do reptiles have a true diaphragm?
no, but it is homologous to mammalian diaphragm
When were the first fossils of reptiles from?
the carboniferous period
What happened in the Carboniferous Period?
great increase in number of plants and insects, this was when amphibian like tetrapods were abundant in aquatic and terrestrial environments
What does the morphology of the first reptiles suggest?
that they are closely related to extinct species of nonamniotic amphibian like tetrapods
What 3 basic lineages of reptiles appear during the late Paleozoic Era?
anapsid
synapsid
diapsid
Explain anapsid.
no temporal opening
appear to be most primitive reptiles
similar to some amphibian like tetrapods
Explain synapsid.
one temporal opening
therapsids appear closely related to first mammals
mammal like reptiles (therapsids)
Explain diapsid.
two temporal openings
Are all mammal like reptiles now extinct?
yes
What animals are diapsid?
lizards
snakes
crocodilians
tuatara
turtles
What are the extinct diapsids?
dinosaurs
plesiosaurs
pliosaurs
pterosaurs
ichthyosaurs
Does reptilia appear to be a valid grouping according to cladistics?
no because its a paraphyletic group
Does reptilia include all modern groups believed to be derived from ancestral reptiles?
no, it doesn’t include birds or mammals
It is hypothesized that birds are direct descendants of what?
dinosaurs
What is the current definition Reptilia?
amniotic vertebrates which are not birds or mammals
What is the Mesozoic Era known as?
Age of Reptiles
When did synapsid animals occur?
during the late Paleozoic era and in the mesozoic era
Recent cladistics consider synapsid animals to be more of what?
stem mammals
What are the primitive synapsids also known as?
pelycosaurs
Describe primitive synapsids.
legs sprawled to the side and not rotated under the body
What is an example of a primitive synapsid?
Dimetrodon
Explain Dimetrodon.
Large sail like structure on back
Relatively large head, jaws, and teeth
Predatory
How were the Dimetrodon’s “sail” formed and what was it used for?
Formed from neural spines of vertebrate; used for thermoregulation and/or display for territory and mate attraction
How long would it take a 200 Kg Dimetrodon to heat from 26 C to 32 C without a sail? With a sail?
205 minutes; 80 minutes
Describe therapsids.
Considered to be the mammal like reptiles that appear closely related to true mammals
Why is it thought that therapsids are closely related to true mammals?
Limbs rotated under body
Skeletal structures
Skull and jaw similarities
What is the one true characteristic that shows therapsids and pelycosaurs are closely related to true mammals?
They only had one middle ear bone
When the pelycosaurs go extinct?
Permian (late Paleozoic)
When did the therapsids go extinct?
End of the Mesozoic era
What are pterosaurs?
Flying reptiles that occurred during the late Triassic to late Cretaceous (middle to late Mesozoic)
When did pterosaurs become extinct?
End of the cretaceous
What was the first flying vertebrate?
Pterosaurs
What was the pterosaur also known as?
Winged lizard or flying lizard
How did pterosaur wings differ from birds?
The fourth finger was extremely long and supported the wing membrane of skin that attached to the arm and body, didn’t have feathers; other fingers had distinct claws
Describe the pterosaur.
Long hollow bones to decrease weight
Well developed sternum for flight muscles
Air sacs
Teeth/beaks
How many species of pterosaurs have been identified?
Over 100
What is the genus of the pterosaurs?
Pterydactylus
What was the size range of pterosaurs?
Sparrow sized to 13 meters
What was the largest pterosaur?
Quetzalcoatlas; 43 ft wingspan
When were pterosaurs abundant? Extinct?
Middle of the Mesozoic; end of the Mesozoic
What were ichthyosaurs?
Specialized marine reptiles that existed during Jurassic and Cretaceous
Describe the ichthyosaurs body.
Similar shape to dolphins; large dorsal fin in some species
Fore and hind limbs that formed paddle like fins
Large tail fin
Large eyes
Long jaws with pointed teeth
What did ichthyosaurs feed on?
Fish and invertebrates
Did ichthyosaurs have eggs or were they live bearing?
Live bearing; fossils have been found with developing embryos inside
What is one of the few reptiles that live their entire life in the water?
Ichthyosaurs
How many ichthyosaur species are there was how big can they get?
Over 100 species; up to 10 meters
What are plesiosaurs and pliosaurs?
Specialized marine reptiles that existed in the Triassic, Jurassic and cretaceous
Describe the plesiosaurs and pliosaurs.
Long bodies with long flipper like limbs
What is hypothesized about the plesiosaurs and pliosaurs fins?
Moved their flippers up and down like wings to fly through the water; they do not use tails for propulsion
What is the most accepted hypothesis of plesiosaurs and pliosaurs?
They were oviparous so they used flippers to crawl out on beach to lay eggs
What did plesiosaurs and pliosaurs feed on?
Fish and other marine reptiles
How large can plesiosaurs an dpliosaurs get?
Up to 13 m
Describe plesiosaurs.
Long necks and relatively small heads
Necks used for quickly flinging head toward prey
Describe pliosaurs.
Shorter necks and huge head and jaws
Largest jaws of any carnivorous vertebrate
How large did some pliosaur skulls become?
(kronosarus) up to 8 ft in length
What does dinosaur mean?
Terrible lizard
When were dinosaurs around?
Form the Triassic, Jurassic, and cretaceous (Mesozoic era)
Describe dinosaurs.
Legs rotated under body due to pelvic and leg bones
What did dinosaurs pelvis and leg bones allow for?
Orientation of legs increased efficiency of their movements
Allowed some to walk upright on 2 legs
What is the key to identifying dinosaurs?
The pelvic bones
How many species of dinosaurs are there?
Approx. 1000
Were dinosaurs initially thought be slow and lethargic or fast and agile?
Slow and lethargic
How did dinosaurs reproduce?
Some laid eggs, some had parental care of eggs and young
What is an example of a dinosaur that had parental care over eggs and young?
Hadrosaurs
When was the earliest of dinosaur fossils found?
From the latter half of the Triassic
When did dinosaurs greatly increase in numbers?
During the Jurassic and cretaceous (were also dominant in this period)
When did dinosaurs become extinct?
During the late cretaceous
What were theropod dinosaurs?
Biped predatory dinosaurs
What were the theropod dinosaur bodies specialized for?
Upright walking and running
Arms were smaller than legs possibly for running faster
What dinosaurs are most structurally similar to birds?
Theropods; some have feathers for insulation
Describe the T-Rex.
One of the largest terrestrial carnivores
Huge head with large teeth (8 in long)
Grew to almost 20 ft
Arms couldn’t reach mouth
What was the max speed of a T-Rex?
40 km/hr or less
What are examples of theropods?
T rex
Velociraptor
Describe the velociraptor.
Agile predator with max size of 1.8 m in height
sharp claws on fingers and toes
What were the largest dinosaurs/animals to ever live in the terrestrial environment?
Sauropods
What is an example of a sauropod?
Apatosaurus (brontosaurus); 70 ft in length and 30 tons in weight
How big were the largest sauropods and what were they called?
130 ft in length and weighed up to 50-100 tons; agentinosaurus (herbivores)
Describe sauropods.
Walked on all 4 legs (hypothesized to be able to stand on 2 to reach leaves)
Long necks
Why did long necks pose problems for sauropods?
Tail acted as counterbalance
Had to have massive hearts to pump blood to their brains
Dead spaces problem ( bird like respiratory to facilitate on way flow of air)
How big is a sauropods heart hypothesized to be?
4 chambered 500 liter heart
Describe stegosaurus.
Herbivore
Large plates extending from back
Spikes on tail to deter predators
Could grow 8 m in length
What were the large plates of stegosaurus thought to be used for?
Deter predators, attracting mates, temp control
Describe Hadrosaurs.
Duck billed ( flat mouths)
Plant or small vertebrate eating
Laid eggs and parental care
Crests on head
What are the crests on the head of a stegosaurus thought to be used for?
Make sounds because it was connected to the nasal passages
When did the KT mass extinction occur?
End of cretaceous
What groups became extinct after KT extinction?
Dinosaurs, pterosaurs, plesiosaurs, ichthyosaurs
What are the orders of reptiles and how many species are in each?
Sphenodonta 2
Crocodilia 24
Chelonia 350
Squamata 9780
What is in the order sphenodonta?
Tuatara
What is in the order chelonia?
Turtles
What is in the order squamata?
Lizards, snakes, worm lizards
Describe sphenodonta.
Resembles lizard
Max length of 2 or 3 ft
More primitive than most reptiles
“living fossil”
What type of skull does sphenodonta have?
Diapsid
Describe sphenodonta teeth.
Serrated projections and fused to jaw
2 rows of upper, 1 row of lower
Gradually wear down and irreplaceable
What kind of heart does sphenodonta have?
3 chambered
Does sphenodonta have an ear drum or openings?
No, have not well developed middle ear
One inner ear bone (stapes)
Poor hearing
Does sphenodonta have well developed third eye?
Yes, covered with a small layer of skin as to only register light intensity
Does sphenodonta have male copulatory organs?
No
Where do sphenodontids occur?
Small islands in new Zealand (relatively cold for reptiles)
How long does it take sphenodontids to reach sexual maturity?
Up to 20 years, while they nay live for 100 or more years; some don’t reproduce until 70-80 years old
How big can adult sphenodonta get?
About 0.8 m in length and 1 kg in weight
What do sphenodonta feed on?
Feed on insects, worms, and other invertebrates also small reptiles; they are primarily nocturnal
Where do sphenodonta live?
In burrows, with a large number of burrows in each colony
How many tuatara can live in a colony?
Up to 7000
How is tuatara an example of a reptile that has adapted to cool environments in the southern latitude?
“physiology in slow motion”; their physiology and reproduction reflect cool environments
Describe tuatara mating.
Occurs by cloaca
Females only nest every 2-5 years
Oviparous and lay around 6-10 eggs and take 12-16 months to hatch
Does tuatara have temp dependent sex determination?
Yes, Type 1A
How long does it take tuatara to sexually mature?
10-20 years and have been known too reproduce at 60 or older
How many species are there of living turtles?
350 species
What is one of the most primitive of living reptiles?
Turtles
What kind of skull do turtles have?
Anapsid
What does research about turtle skulls show?
They may have actually been diapsids that lost their temporal openings
When are the first fossils of turtles from?
Triassic approx. when dinosaurs appeared
Describe Proganochelys and Triassochelys.
Turtle fossils from the Triassic
Up to 0.5 m in length
Earliest known turtles
Similar to modern turtles
Describe Archelon.
Giant sea turtle that lived during cretaceous
2 m shell length
Where do many modern groups of turtles fossils date back to?
Cretaceous
Describe a turtle shell.
Key to survival
Made of bony plates covered by cornified scutes (made of keratin)
Carapace is upper shell, composed of thoracic vertebrae
Plastron is lower shell
Describe turtle respiration.
Don’t have a diaphragm, ribs cant move in and out due to shell
Can increase and decrease volume in shell by contracting muscles
Movement of limbs move air in and out of lungs
Describe turtle reproduction.
Internal fertilization, males have single penis
Female turtles store sperm
Oviparous
Temp dependent sex determination
How long can turtles live?
Over 100, possibly 150-200
Do turtles have teeth?
No, have tough horny plates of keratin over bony jaws for biting and crushing
What do turtles eat?
What turtles are carnivores?
Snapping turtles and sea turtles
What turtles are herbivores?
Tortoises and green sea turtles
What are the two basic groups of turtles?
Cryptodira (hidden necked 75%) and pluerodira (side necked)
How many species of hard shelled sea turtles are there? Leatherback?
6; 1
How did sea turtles adapt to marine existence morphologically and ecologically?
Their legs modified into flippers and cannot pull their head back into the shell
What do sea turtles feed on?
`Variety of invertebrates like crabs, shrimp, and clams, some eat sea grasses
How many eggs do sea turtles lay per nest?
About 100
Describe sea turtle nesting.
Some will nest 2-6 times a year, but other will nest up to 12; females take 1-3 years off before nesting again
Where do snapping turtles occur?
South and eastern U.S. as well as alabama
Describe the common snapper.
Smaller than alligator snapping
Can grow 1.5 ft in length
Occurs in central and eastern US
Describe the alligator snapper.
Largest freshwater turtles in north America
Worm like structure on tongue (used to lure fish into biting range)
80 years or more life span
What was the largest alligator snapping turtle on record?
Weighed over 90 kg (200 lbs)
What is the alligator snapper historically used for?
Turtle soup
Describe tortoises.
Terrestrial turtles with high dome shells
Mostly herbivorous
Describe gopher tortoises.
Burrows in sandy soil (30 ft in length or more)
Lays eggs outside burrow
Herbivore
Can be 12 in or more in length
Occurs in southeastern US (including AL)
Describe Galapagos tortoises.
Largestest tortoises in the world
15 subspecies, only 11 surviving
How large can Galapagos tortoises get?
Weight of over 225 kg but can reach up to 600-800 lbs
Why are there only 11 subspecies of Galapagos tortoises left?
Heavily exploited by mariners by the whaling industry
What is Lonesome George?
Thought to be the only remaining member of one subspecies, died in 2012
Describe softshell turtles.
Soft and leathery shell
Aquatic
Long snouts “snorkels”
Carnivores
Fast with sharp claws & jaws (very strong bite)
Distributed through US including AL
Describe sliders, scooters, and painted turtles.
Typical pond turtle
Low dome shell
Slide into water when predator approaches
Omnivores
What is an example of the Emydid turtle family?
Sliders, scooters, and painted turtles
Crocodilians are a very ancient group of reptiles, what are they an example of?
Living fossil
When do crocodilian fossils date back to?
Late Triassic early Jurassic
What are the largest living reptiles?
Crocodilians
How big can crocodilians become?
Over 7.5 m in length and over 1000 kg in weight
How long can the nile crocodile get?
21 ft
What species from the cretaceous grew to 40 ft?
Supercroc/ sarcosuchus
Describe crocodilian reproduction.
Internal fertilization
Single penis everted through cloaca for sperm transfer
Lay eggs
Bellowing
Temp dependent sex determination
Parental care
Do crocodilians have good hearing?
Yes
How do crocodilians exhibit parental care?
Sounds of hatchling cues mother to open nest
Mother carries hatchlings on body/mouth
How long can crocodilians live?
70-100 years in captivity
Describe Gharial.
Long and narrow snout for catching fish (quick side to side movement)
Can grow 15-20 ft
What is the only living species of Gharial?
The Indian Gharial, critically endangered due to habitat loss and fishery
Describe crocodiles.
Narrow snout
4th tooth on lower jaw is visible when mouth is closed
14 living species
Describe alligators.
Broad snout
8 living species
What are the 8 living species of alligators?
American and Chinese alligators and 6 species of caimans in central & south America
Where are American alligators found?
Southeastern US
Central and south America
How big can American alligators get?
Max of 19 ft, they mature at 6 ft
When does mating take place in American alligators and what does it look like?
Takes place in spring with males bellowing loudly; female builds mound nest of mud and vegetation, lays 20-70 eggs and guards nest
What happens when the hatchlings hatch?
After 2 months the eggs hatch and make a high pitched noise to attract mother and mother helps them out, she protects them for up to a year or more
Where is the American crocodile found and how big can it get?
Florida keys and everglades
Caribbean, central and south America
6 m and 2000 lbs
What is the most recent of the living reptiles in the fossil record?
Order squamata
When did squamates begin radiating?
Cretaceous period towards end of the Mesozoic era
What is the most successful group of living reptiles?
Order squamata; over 10,000 species 95% of living reptiles
What is it hypothesized that snake and worm lizards evolved from?
Lizard like ancestors
How many species of lizards are there?
About 6000
Where are lizards found and how large can they get?
Temprate and tropical climates; an inch to 10 ft
Describe mosasaurs.
Grew up to 10 m or more
Carnviores
Existed during cretaceous
What was one of the first prehistoric skeletons found by humans?
Mosasaurs
What is well developed in lizards?
Sight, smell, and vomeronasal organ in roof of mouth
What is the VNO used for?
detects airborne chemicals like pheromones
What is the vomeronasal organ also known as?
VNO or jacobsons organ
What can the pineal eye have?
Cornea, lens, and retina
Describe lizards ears.
External ears
Middle ear has columella bone
Don’t use sound for mating or territory (except some geckos)
What are lizards also known as?
Sauria/lacertilian
What do lizards feed on?
Carnivores, many eat insects; some feed on mammals (Komodo), some are herbivores
What lizards tongue can be longer than their body?
Chameleons
What lizards are herbivores?
Iguanas
How do lizards reproduce?
Internal fertilization
Males have hemipenes
Oviparous, ovoviviparous, and viviparous
What lizard is viviparous?
Brazilian skink
What is parthenogenic and are some lizards it?
Eggs develop without being fertilized, yes (species all female)
Are some lizards temp dependent sex determinate?
Yes
What is an example of a parthenogenic lizard?
Species of whiptail lizards in southwestern US
What is the draco lizard?
Flying dragon, has folds of skin that act as wings for gliding
What is the Basilisk lizard?
Runs on hind legs
Known to run across water on hind limbs
What is the Gila monster?
Venomous lizard in SW US
Small fangs
Chew prey to enhance venom transfer
Not fatal to humans
What is the Komodo dragon?
Largest lizard in the world
Found in Indonesia
9 ft or longer
Produces venom
What are snakes also known as?
Serpentes
How many species of snakes are there?
3400
How big are the smallest snakes? Largest?
15 cm; over 11 m
How large is the largest anaconda reported?
11.4 m
How big can the reticulated python get?
10 m
What snakes have remnants of pelvic girdle bones?
Boas and pythons
What do snakes have instead of eyelids?
Transparent membrane covering it, the membrane is shed during the molt
Do snakes have external ears or tympanic membranes?
No, but they do have inner ears and a columella
How do snakes pick up sounds?
Low frequency vibrations conducted through the bones, especially the jaw, then transfer the vibrations to the columella
Describe the organs inside of a snake.
Organs are long and thin
Most paired organs are one right behind the other
Most only have one fully functional lung, left lung is repressed
Where are heat sensitive pits found in pit vipers, boas, and pythons?
Between nostrils and eyes
Found near lips in boas and pythons
How does a pit organ work?
Have suspended membranes with receptors that detect infrared radiation
Senses warm blooded animals
How are the bones of a snake skull connected?
Loose ligaments so entire skull can flex
Are the right and left lower jaws of snakes fused together?
No, this is so they can operate independently of one another
What does the glottis do in snakes?
is at the front of the mouth (opening of trachea) and prevents suffocation while swallowing large prey
What kind of feeders are snakes?
Episodic feeders, normally eat once or twice a week (some only eat once or twice a month)
What are the different ways in which snakes immobilize prey?
Bite and hold with mouth
Constriction
Venom
What percentage of snakes are venomous?
20-25%
How is venom produced?
By modified salivary glands in upper jaws
What proteins can venom contain?
Neurotoxins that block neuromuscular junction and cardiovascular toxins
Toxins and enzymes that cause tissue destruction and hemorrhage
How many people are bitten each year in the US by snakes? How many died?
4000-6000; approx. 5 or less
How many people are bitten each year in India by snakes? How many die?
200,000; several thousand
How do snakes reproduce?
Internal fertilization by male hemipenes
How does reproduction vary in snakes?
Some lay eggs, some bear live young; however they don’t show parental care but will protect the eggs
How do sea snakes reproduce?
Ovoviviparous and bear live young
What is an example in diversity in reproduction in snakes?
Red sided garter snakes; form large mating aggregations up to thousands of snakes, they wait for females to come out from hibernation
What has the release of pythons in Florida done for the ecosystem?
Resulted in decline in mammal populations in everglades, such as rabbits, foxes, raccoons, opossums and deer
How many species of worm lizards are there?
180
What is another name for worm lizards?
Amphisbaenia
Where are worm lizards found and where to they live?
Most occur in south America and Africa; live in the ground
How are worm lizards adapted to the subterranean environment?
Most lack legs
Worm like appearance
Small eyes and ears covered by skin (has columella that connects to skin)
Are worm lizards the only reptile that are primarily or exclusively subterranean?
Yes
What does amphisbaenia mean?
Double walk or double moving
What are worm lizards called in latin America?
Snake with two heads
What do worm lizards feed on?
Carnivores, eat worms, insects, and other invertebrates; have strong jaws for biting and crushing prey
How do worm lizards reproduce?
Internal fertilization
Males have hemipenes
Oviparous/ ovoviviparous
What is the one species of worm lizard found in the US called and where does it occur?
Florida worm lizard; found in florida and southern alabama
