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BIOL 2030 Lecture Notes - Pennaceous Feather, Feather, Cervical Vertebrae

Course Code
BIOL 2030
Scott Kelly

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A subclass of primitive reptile-like fossil birds including archaeoptyrex
Birds, a class of bipedal homoiothermic vertebrates having the body clothed in feathers
and front limbs modified as wings, and the skin of the jaw forming a horny bill (beak).
They are descended from the extinct archosaurian reptiles.
One of the delicate threadlike structures extending from the shaft of a feather and
forming the vane
Lateral projection from barb of feather, serving to hold barbs together to form an
unbroken vane
Contour Feathers
Outermost feathers that cover the body of birds
Down Feathers
The first fluffy feathers of young brids, with a short quill and with barbules not
interlocking to form a flat vane. Some birds retain a down layer under adult plumage
Delicate hair-like feather with long axis and a few free barbs at apex
Sheath of epithelium surrounding hair or feather root
The united clavicles of birds, the wishbone
Hand, or part of forelimb corresponding to it, as present in amphibians, reptiles, and
Superorder of “new jaw”-ed birds, mainly flying
Subclass of birds, including all extant modern birds
The ratites, flightless birds of the subclass Neornithes such as the kiwis, cassowaries,
and strich, which are secondarily flightless
Breast muscle connecting breastbone with humerus, much enlarged in birds where it is
a main flight muscle
Pelvic Girdle
In vertebrates, a skeletal support in the hip region for attachment of hind-fins or
hindlimbs, made of a hoop of cartilages or bones
Having air cavities
A compressed upturned bone at end of vertebral column in birds, composed of fused
The central shaft of a feather
Stalk of feather or hair
Breastbone in vertebrates
A flight muscle in birds, running indirectly from breast bone to humerus and responsible
for raising the wing
Mass of fused vertebra supporting the pelvic girdle of birds
Unciate Process
A hook shaped process on the lateral borders of the superior surface of vertebral bodies
of the third to seventh cervical vertebrae
The web of a feather, consisting of the thread-like barbs
Air Sacs
Spaces filled with air and connected with lungs in birds
Organ specialized for the respiratory uptake of oxygen directly from air and release of
carbon dioxide to air
In birds, the main trunk of a bronchus giving rise to secondary bronchi
One of numerous small tubules in lungs of birds, connecting dorsobronchi and
ventrobronchi, and in which respiratory gas exchange takes place
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Brief Breakdown **SPECIES POINT**
Archaeoptyrex ~147myo, connective link between birds & dinosaurs
o A class of both reptiles & birds
o @ caudal region, vertebra runs to the very tip (see pic farther down)
Definitive morphology: SHAPED 4 FLIGHT
Little size difference, 2g min vs 20g max
Teratorn sp. [~80kg!] extinct
Flight imposes restrictions weight-
reduction & other physiological factors
ONLY IN BIRDS: defining characteristic
Contour Feathers [body & flight feathers]
o Aerodynamic contour: streamlines body surface, lightweight, strong covering
o Quill (from skin follicle), Shaft (continuation of quill, supporting barbs), Barbs (arranged in
parallel, spread diagonally from shaft ASYMMETRICAL vanes), Barbules link adjacent barbs by
overlapping hooks
o Preening (running beak parallel to barb axis) reattch barbules
o Asymmetrical + can rotate slightly
o @ downstroke air resistance, @ upstroke reduced resistance
o Homologous to reptile scales little elevation first forms, then follicle
o Dev. From epidermal elevation (supplied by dermal core)
o Roll into cylinder & sink to follicle, growing the feather
Pigments added, shaft/barbs keratinize [strength]
Protective sheath splits open
o Ordered moulting [symmetrical shedding of few pairs, & grow, repeat 4 other]
o exception: WATER FOWL (shed all @ once & hide b4 regrowth]
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