Vertebrate Biology Flashcards
Monophyletic
CA + all descendants
Polyphyletic
Doesn’t include CA of all groups
Paraphyletic
Group descended from CA but doesn’t include all descendant groups
Chordate features
- Dorsal notochord
- Dorsal nerve chord
- Bilateral symmetry
- Pharyngeal slits
- Endostyle
Lower vertebrates
- Jawless fish
- Chondrichthyes
- Osteichthyes
- Lissamphibia
Higher vertebrates
Amniotes:
- Testudines
- Lepidosauria
- Crocodilia
- Aves
- Mammalia
Vertebrate features
- Postanal tail
- Pharyngeal pouches
- Vertebral column
- Anterior brain
- Craniates
- Closed circulatory circuits
- W-shaped myomeres
- Organ systems
Dorsal fin
Anti-roll stabilising
Pectoral fin
Steering + lift
Pelvic fin
Stabilisers
Caudal fin
Thrust
Types of lift
- Dynamic
2. Static
Chondrichthyes osmoregulatory adaptations
- Isotonic
- High urea and TMAO concentration
- Large glomeruli
- Rectal gland
- Low ion and urea permeability in gills
Scale types
- Placoid
- Cosmoid
- Ganoid
- Ctenoid
- Cycloid
Gas bladder connections
- Physostomus
2. Physoclistous
Fish body locomotion
- Anguilliform
- Carangiform
- Subcarangiform
- Thunniform
- Ostraciforms
Fish fin locomotion
- Tetraodontiform
- Labriforms
- Amiiform
- Gymnotiform
- Balistiform
Types of drag
- Viscous
2. Inertial
Ampullae of Lorenzini
Electroreceptors
Lateral line
Mechanical system
Anguilliform
Whole body movements
Subcarangiform
Tail and posterior sides
Amphibian teeth
Pedicellate
= crown, uncalcified mid section + dentine base
Amphibian Skin glands
- Mucous
- Granular
3 Hedonic (some males)
Amphibian Sound detection
- Basilar papilla: 1200-1600Hz
2. Amphibian papilla: 200-800Hz
Carangiform
More oscillating than sub
Amphibian Skin pigments
- Melanophores - Black,Brown, red
- Iridophores - reflect light
- Xanthophores - yellow, orange, red
Thunniform
Only tail
Ostraciform
Tail movement as body rigid
Tetraodontiformes
Dorsal and anal fins
Labriforms
Pectoral fins
Amiiform
Dorsal fin undulations
Gymnotiform
Anal fin undulations
Balistiforms
Anal and dorsal fin undulations
Tetrapod ancestor
Elpistostegid
Closest tetrapod relative
Tiktaalik = Devonian fossil
Acanthostega
Late Devonian (360 mya) stem tetrapod
Ichthyostega
Late Devonian (360 mya) Atem tetrapod
Terrestrialisation adaptations
- Skeletal
- Zygapophyses
- Lungs
- Kidneys
Temnospondyls
Stem lissamphibians (modern amphibia sister group) until early Cretaceous (130 mya)
Amphibian respiration
Buccalpharyngeal pumping forces air in via positive pressure
Amphibian adult photoreceptors
Rods:
- Red detect green
- Green detect blue
- Purple detect UV (only larval and aquatic)
Cones:
- Single detect yellow
- Double
Snake fangs
- Opisthoglyphous =rear fanged
- Proteroglyphous = permanently erect
- Solenoglyphous = rotate via pterygoid movement
Flexible paedomorphosis in mole salamanders:
- Isotypic
2. Paedotypic
Anuran skeletal modifications
- Reduced vertebral column
- Strong zygapophyses
- Fused vertebrae
- Large leg muscle attachment points
Anuran breeding types
- Explosive
2. Prolonged
Gymnophiona characteristics
- Legless
- Short tails
- Reduced eyes
- Dermal scales
- Annuli
- Protrusible tentacles
Amniotic traits (370mya)
- Keratinised skin
- Kidneys excrete concentrated urine
- Coastal lung ventilation
- Intrinsic muscles
- Teeth
- Amniotic egg
Amniotic egg embryonic membranes
- Amnion
- Chorion
- Yolk sac
- Allantois
Skull morphology
- Anapsid
- Synapsid
- Diapsid
Reptilia
Carboniferous = 360-290mya
Saurischia
Rotate pubis anteriorly
- Sauropodomorphs
- Theropods
Ornithischia
Rotate pubis posteriorly
Main lineages:
- Armoured
- Horned
- Duck-billed
Key testudinian features
- B-keratin Shell:
- Carapace (top)
- Plastron (underneath) - Vertebral column and ribs fused to carapace
- Static lungs
- Diaphragmatic ventilation
Testudines respiratory methods
- Pharyngeal
- Hydrostatic H2O pressure
- Cloacal
Testudines
- Cryptodires - vertical
2. Pleurodires - horizontal
Snake specialisations
- Fossorial (ancestral?)
- Epigean
- Aquatic
Snake locomotion
- Lateral undulations
- Rectilinear
- Concertina
- Sidewinding
Squamate sex determination
- Genotypic
- Temperature
- Behavioural
Squamata thermoregulation
- Morphological
- Behavioural
- Physiological
Bird- reptile similarities
- Occipital condyl
- 1 middle ear bone
- Nucleated erythrocytes
- Heterogametic females
- Jointed hind limbs at tarsal bones
Bird - mammal differences
- Mammals have 3 middle ear bones
- Mammals have non-nucleated erythrocytes
- Male mammals are heterogametic
- Mammals have jointed hind limbs between tibia and tarsi
Theories of bird origin
- Thecodont
2. Theropod
Bird wing features
- Airfoil shape
- Angle of attack
- Slotting
- Alula
Archaeopteryx
Bipedal reptile with both reptilian and bird features
Semi arboreal
Sinornis
Early Cretaceous
Intermediate between Archaeopteryx and modern bird features
Confusciornis
Late Jurassic/ early Cretaceous
Modern beak but no keel
Sinornithosaurus
Dinosaur
Flight pre-requisites but not feathers
Unenlagia
Late Cretaceous
Half bird
Sinosaurapteryx
Proto-feathers and melanosomes
Protoarchaeopteryx
Late Jurassic/ early Cretaceous therapod
Caudipteryx
Late Jurassic/ early Cretaceous coelurosaur therapod
Remiges and retrices but no flight
Basal tyrannosaurid
Early Cretaceous
Protofeathers
Epidexipteryx
New basal avian?
Bird features
- Furcula
- Sideways flexing wrists
- Feathers
- Keel
- Nesting behaviour
- Hollow bones
- Rapid growth rates - cartilage discs
Avian wing structure
- 2 vs 10 free carpals
- 3 hand digits = equivalent to mammal 2,3,4 but same mesenchymal condensations
- Fused hand and finger bones
Progenesis
Last structured to develop are lost first
Eg digit reduction of 1 and 5
Flight theories
- Arboreal - parachuting/ gliding
- Cursorial - jumping
- Wing-assisted incline running (WAIR)
- Ontogenetic Transitional Wing (OTW) (Dial et al.)
Bird aerodynamics
- Net lift due to differences in distance travelled by air over feathers
- Laminar flow
- Minimise turbulence
- Increase wing curvature but too steep = turbulence
- Stall if AOA too steep
Drag
- Profile
2. Induced
Flight adaptations
- Pneumatic bones
- Toothless bill
- Feathers - symmetrically and asymmetrically vaned. Remiges and rectrices
- Deep keel
- Rigid thorax
- Pectoral girdle forms triangular strut system
- Wings: powerful tendons, flexibility, large joint surface
Bird wings
- Primary feathers
2. Secondary feathers
Primary feathers
Generate thrust on downstroke
Over hand
Friction barbules
Secondary feathers
Generate lift
Attached over ulna, radius and humerus
Bird muscles
- Pectoralis - thrust generator kn downward stroke
- Supracoracoideus- take off and pulls wing up for recovery stroke
- Dorsal elevator muscles
Bird wing shape
- Elliptical
- High speed
- High aspect ratio (active soaring)
- Slotted high lift (passive soaring)
- Hovering
Flight without flapping
- Gliding
2. Soaring
Soaring
- Static - thermals or obstruction currents
2. Dynamic
Flapping flight
- Flap-gliding
2. Flap-bounding
Static aerodynamics
Total lift for each part of the flap cycle
Ratites
Flightless birds
Raft-like sternum
Palaeognathous palate
Carinates
Keeled sternum
Neognathous palate
Pelycosaur features
Late Carboniferous/ early Permian mammal
- Primitive heterodonty
- Parasagittal gait
- Dorsal sail with elongated neural spines
- Parietal foramen
Therapsid features
Late Permian mammal
- More upright stance
- Rib reduction
- Larger temporal fenestra
- Differentiated teeth
Cynodont features
- Lumbar ribs lost
- Diaphragm
- Secondary hard palate
- Enhanced thermoregulation
- More heterodonty
- Zygomatic arch
- Sagittal crest
- Reduced articular-Quadrate jaw
Tinamous
Palaegnathous
Keeled sternum
Bird feather composition
Beta-keratin
Melanin
Carotenoid pigments
Feather types
Neossoptiles:
- Down = insulation
- Powder down
Teleoptiles:
- Contour
- Bristle = sensory and protection
- Filoplume = Monitor movement and position via receptors
- Semiplume = Insulation and courtship
- Flight = retrices and remiges
Feather arrangement
- Pterylae
2. Apteryia
Uropygial glands
At tail base
Aka preen gland
Secretes oils
Feather development
Dermal condensation
Support system - reabsorbed by follicles at the end
Anchored in follicle
Apoptosis
Feather evolution
- Scale elongation
- Rachis development
- Vane differentiation into barbs
- Barbules and barbicels
Moulting types
- Ptilopaedic
2. Psilopaedic
Key bird life events
- Breeding
- Moulting
- Migration
Migrant types
- True
2. Partial
Navigational cues
- Innate vector orientation
- Solar
- Landmarks
- Stellar/ lunar compass
- Olfaction
- Magnetic compass
- Genetic
Bird respiratory adaptations
- Air sacs
- Aerodynamic valving
- Rigid lungs
- Continuous unidirectional airflow
- Cross current exchange: air and blood via arterioles
- Counter current exchange: blood and air at organ level
Bird thermoregulatory Methods
- Downy feather presence/ absence
- Feather colour
- Blood flow to feet
- Arteriovenous shunt
Types of bird young
- Precocial
- Semi-precocial
- Semi-altricial
- Altricial
Mammalian characteristics
- Mammary glands
- Synapsid skull
- Hair
- Heterodonty
- Dentary- squamosal jaw articulation
- 3 middle ear bones
- Enamelled teeth
- Placenta
- Tribosphenic cheek teeth and occlusion
Why did endothermy evolve?
Sustain increased locomotion and metabolic rates
What does the haderian gland do in mammals?
Produce waterproofing oil for hair. Gland is by the eye
Mammalian teeth features
- Crown
- Base
- Dentine
- Pulp
- Cement
- Enamel
Dental formula
Incisor: canine: premolar: molar
Types of mammalian cheek teeth
- Bunodont
- Lophodont
- Hypselodont
- Polyphyodont
- Hypsodont
- Selenodont
- Sectorial
Types of fermenters
- Foregut
2. Hindgut
Characteristics of antlers
- Live tissue - require blood and have nerves
- Shed annunally
- Males
- Skull extension - outgrowth of frontal bone
- Lobes - tines
Characteristics of horns
- Both sexes
- Outgrowth of frontal bone
- Bone and keratin
- No lobes
Stance types
- Plantigrade
- Digitigrade
- Unguligrade
- Graviportal
Types of unguligrade
- Perissodactyla ie odd toed
2. Artiodactyla ie even toed
Fossorial types
- Rapid scratch diggers
- Rotation thrust diggers
- Chisel tooth diggers
Mammalian Locomotor types
- Cursorial
- Fossorial
- Arboreal
- Volant
- Amphibious
- Aquatic
Types of mammalian distribution
- Vicariance
2. Dispersal
Great American Biotic Interchange
When the America’s rejoin 2.5mya via Panamanian isthmus enabling movement between N and S America of marsupials and placentals
Ecomorphological equivalence
Independently derived features that are anatomically different but functionally similar
Types of cladistics
- Morphological - form and function
2. Molecular - mtDNA
Homology
Similar characteristics due to a CA
Homoplasy
Similar characteristics but not because of a CA eg convergent evolution
Mammalian convergent evolution
- Monotreme and marsupial pouches
- Dietary and niche specialisations
- Amphibious forms and adaptations
- Marsupial and placental placenta
- Marsupial and placental astragalus bone
- Heterodonty
- Placental herbivores and cursorial locomotion
- Placental echolocation
Monotreme features
- Non therians
- Lay eggs and incubate externally
- Mammary hairs
- Cheek teeth replaced by bill
- Internal testes
- Single hole - cloaca
Marsupial features
- Therians
- Viviparous
- Nipples and mammary hairs
- Tribosphenic molars - monophyodont
- No sclerotic cartilage
- Separate anus and urogenital sinus
- Testes outside body wall
- Paired virginae and bifid penis
- Choriovitelline placenta
- No tympanic bulla
Placentals features
- Therians
- Viviparous
- Nipples but no mammary hairs
- Tribosphenic molars - diphyodont
- No sclerotic cartilage
- Chorioallantoic placenta
- Medial vagina and simple penis
Types of placenta
- Choriovitelline
2. Chrorioallantoic
General marine mammal adaptations
- Morphological eg paddle like limbs, elongated phalanges, vestigial hindlimb, no zygapophyses
- Blubber/ fur
- Positively charged myoglobin
- Countercurrent heat exchangers
- Remove salt from food and don’t drink sea water
Mysticeti families
- Balaenidae
- Neobalaenidae
- Balaenopteridae (roquals)
- Eschrichtiidae
Odontoceti families
- Delphinidae
2. Phocoenidae
Humpback whale groups
- Female, calf + escort
2. Bachelor herds
Advantages of large group sizes
- Dilution effect
- Group attack
- Reduced individual vigilance time
- Mates
- Cooperative foraging
Disadvantages of large group sizes
- Competition
- Inbreeding
- Disease
Phocidae species
- Monk - Hawaiian, Mediterranean
- Antarctic - Ross, Leopard, Crabeater, Weddell
- Elephant - N and S
- Northern Hemisphere - 10 species
Otariidae species
- Fur seals - 10 species
2. Sea lions - 5 species
Odobenidae
Walrus
Definition of lango
Otariid baby fur
What is chorionic gonadotropin and what does it do?
A placental hormone which blocks ovulation and maintains pregnancy in Pinnipeds
Foraging issues faced by marine mammals
- Navigation - “featureless”
- 3D prey distribution - often uneven
- Environmental factors
- Physiology
Marine environmental features
- Oceanography
- Surface circulation - gyres and wind patterns
- Great Ocean Conveyor Belt
- Coastal Upwelling
- Bathymetry
- Fronts
- Eddies
- Sea Surface Temperature (ENSO)
Foraging behaviour factors
- Prey species
- Bathymetry
- Time of day
- Time of year
- Physical condition
- Diel prey migration
Marine mammal dentition
- Piercing
- Spikes
- Cage-like
- Conical
Foraging strategies
- Mesopelagic
- Benthic
- Epipelagic
Dive shapes
- Soft square
- V/U
- Hard square
- Skewed right
- Skewed left
Elephant seal dive types
- Foraging
- Processing
- Travelling
O2 stores for diving mammals
- Lungs
- Blood
- Muscle
Deep diver adaptations
- Haematocrit
- O2 more loosely bound to haemoglobin
- Greater blood volume
- Enlarged spleen with O2-rbc
- Sphincter for gradual O2-blood distribution
- Hepatic sinus
- Increased body size
- Larger O2 stores
- Reduced metabolic rate
Hypometabolism techniques
- Vasoconstriction
- Increased hypoxia tolerance
- Bradycardia
Diving response characteristics
- Increased anaerobic reliance
- Reduced metabolic rate
- Reduced cardiac output
Processing lactate
- Oxidise at surface
- Recycle to glucose at surface
- Oxidise during subsequent dives
- Recycle during dives
Desert adaptations
- Furred feet
- Water conservation
- Concentrated urine
Defence mechanisms
- Spikes
- Horns
- Hiss-puff
- Stripes
- Warts
Scansorial adaptations
- Hindfeet point straight back
- Prehensile tail
- Textured footpads
- Shortened limbs
Water-based adaptations
- Webbed feet
- Elongated lungs
- Valvular eyes and nostrils
- Fur
- Paddle-like tail
- Large body mass
- Nictating membranes
- Vibrissae
- Reduced olfaction (marine mammals)
Dietary/ feeding adaptations
- Mandibular fossa
- Echolocation
- Cheek pouches
- gape-limited predator
- tweezer-like teeth
- tool usage
- Locking jaws