EEB384 Midterm

Paraphyletic

not all crown group members included (e.g., birds excluded from reptiles)

Polyphyletic

group derived from more than one MRCA (e.g., herps = amphibians and reptiles)

Amphibian Traits

anamniotic egg, thin skin, metamorphosis

Reptile Traits

amniotic egg, scaly skin

Amniote

embryo protected by amniotic membranes that conduct active gas exchange and prevent dessication

Caudata (salamanders/newts)

elongate trunk/tail, mostly 4 limbs, ancestrally biphasic

Anura (frogs/toads)

short trunk no tail, 4 limbs, ancestrally biphasic

Gymnophiona (caecilians)

elongate trunk short tail, limbless, reduced eyes, chemosensory tentacle, ancestrally biphasic

Crocodylia (crocodylians)

elongate trunk/tail, 4 limbs, oviparous, exhibit parental care, aquatic or semiaquatic

Testudines

shell, 4 limbs, oviparous, pelvic/pectoral girdle inside ribcage/skull, terrestrial aquatic or semiaquatic

Rhynchocephalia (tuatara)

medium trunk/tail, oviparous, carnivorous, terrestrial or nocturnal

Lizards (Squamata)

variable trunk/limb dimensions, 4 or 2 or 0 limbs, terrestrial arboreal or semiquatic, herbivorous to carnivorous

Snakes (Squamata)

very elongate trunk, short or long tail, terrestrial/arboreal/fossorial/semiaquatic/aquatic, oviparous origins, strictly carnivorous

Cryptic Species

taxa that are indistinguishable morphologically

Tiktaalik

aquatic sarcopterygian fish with robust pelvic/pectoral girdles and a free neck

Temnospondyl Hypothesis

lissamphibians lie within the temnospondyl amphibian clade

Lepospondyl Hypothesis

lissamphibians lie within lepospondyl

Diphyly Hypothesis

lissamphibians are polyphyletic - frogs/salamanders are temnospondyls, caecilians are lepospondyls

Lissamphibia Synapomorphies

bicuspid + pedicellate teeth, operculum sound transmission apparatus, skin contains mucous and poison glands, retractor/levator muscles in eye can retract/elevate eye, short ribs don't encircle body

Caecilian Synapomorphies

no limbs/appendicular girdle, annuli muscle rings, tentacle sensory organ, tail reduced/absent, internal fertilization via phallodeum

Salamander Synapomorphies

costal grooves, larvae have bony skeletons, no tympanum/middle ear cavity

Anura Synapomorphies

extremely reduced skull, fused frontals/parietals, backwards tongue, 9 or less sacral vertebrae, caudal vertebrae fused into single rod, radius/ulna fused, tibia/fibula fused, no teeth in mandible, distinctive larvae

Synapsida

mammals + non mammalian synapsids

Sauropsida

reptiles

Amniote Clades

synapsida, sauropsida

Diapsida

all living reptiles

Living Reptile Groups

archosauria, lepidosauria, lepidosauromorpha

Scales

folded areas of epidermis

Osteoderm

bone slivers/plates found within dermis of crocodilians and some lizards

Scutes

similar to scales, develop directly on underlying bone

Reptile Characteristics

scale like feature, shedding, scale organs, ear structure, vision

Columella

sound transmitting bone

Scleral Ossicles

thin bone plates embedded in sclera of the eye

Crocodylian Synapomorphies

thecodont teeth, webbed feet, robust osteoderms

Turtle Synapomorphies

shell, lack of teeth, lack of temporal fenestrae

Anapsid Hypothesis

turtles lie outside Diapsida, most closely related to extinct parareptiles

Archosaur Hypothesis

turtles are sister to Archosauria

Lepidosaur Hypothesis

turtles are sister to Lepidosauria

Major Turtle Clades

pleurodires, cryptodires

Plerodires

turtles that retract neck laterally

Cryptodires

turtles that retract neck dorsoventrally

Autotomy

ability to shed tail in defense, usually regenerated

Lepidosaur Synapomorphies

epiphyseal long bone growth, skin shed all at once, autotomy, fused astragulus/calcaneum, hooked fifth metatarsal

Rhynchocephalian Synapomorphies

intact temporal bar, tympanum absent, acrodont teeth with palatine tooth row, propalinal shearing, abdominal ribs - cover stomach

Squamate Synapomorphies

movable quatrade bone, hemipenes, specialized tooth attachment modes (acrodont, pleurodont, and modified pleurodont)

Major Squamate Clades

iguania, scleroglossa

Snake Synapomorphies

>120 procloacal vertebrae, no scleral ossicles, loss of many skull elements, several lower jaw bones fused into single compound bone, loss of several hyoid elements, long/slender/curved teeth

Sources of Water Uptake

liquid water, preformed water, metabolic water

Cutaneous Water Exchange

water acquired through the skin (e.g., amphibians)

Methods of Water Loss

evaporation, excretion

Forms of Nitrogenous Waste

ammonia, urea, uric acid, salt glands

Q10 Effect

rate of change in a biochemical reaction with a 10 C increase in temperature

Thermoregulators

employ morphological, physiological, and behavioural mechanisms to maintain body temperatures that differ from environmental temperatures

Set Point Temperature Range

preferred temperature range of an organism, determined experimentally

Thermoconformer

organism that does not maintain body temperatures that differ from their environment

Heliothermy

use of solar radiation for thermoregulation

Thigothermy

conduction of heat from a substrate for thermoregulation

Kleptothermy

gain heat from metabolic heat production of endotherms

Physiological Thermoregulatory Mechanisms

colour change, circulatory transport, metabolic heat production

Countercurrent Heat Exchange

coupled veins/arteries allow for heat to be lost to body instead of environment

Newton's First Law of Motion

body at rest/in motion will remain so until a force acts upon it

Newton's Second Law of Motion

force = mass*acceleration

Newton's Third Law of Motion

every action has an equal and opposite reaction

Centre of Gravity

the centre of mass of an object

Base of Support

area enclosed by points of contact with the ground

Reaction Force Components

vertical component, propulsive component

Levers: First Class

fulcrum lies between in lever and out lever

Levers: Second Class

fulcrum lies at one end of bar, in force applied at other end, force generated between both ends

Levers: Third Class

fulcrum lies at one end of bar, in force is applied at both ends, out force generated at opposite end from fulcrum

Sprawling Gait Locomotion

lateral undulations combined with alternating limb movements

Semierect Gait Locomotion

limbs more vertical during locomotion

Morphological Specializations for Jumping

long hindlimb elements, ankle independent of foot, pelvic girdle not fused to vertebral column

Lateral Undulation Locomotion

body pushes posterolaterally, generating reaction with forward and lateral components

Concertina Locomotion

anterior and posterior regions take turns anchoring the body while other parts move forward

Sidewinding Locomotion

sections of body are continuously lifted, moved forwards, and set back down

Rectilinear Locomotion

moving forward in a straight line

Undulatory Swimming

undulation based propulsion

Oscillatory Swimming

appendage based propulsion

Morphological Specializations for Burrowing

smooth skin, reduced number of scales, thicker skull bones, reinforced skull sutures

Wet Adhesion

capillary adhesion, relies on surface tension in a lubricating fluid to create an adhesive bond between organism and substrate

Dry Adhesion

lamellae covered in setae bond to substrate via van der waals forces