Exam 1: Bird Evolution, Feathers, Anatomy

Name of the dinosaur that provided evidence that birds evolved from reptiles

Archaeopteryx

Theropods

Major subgroup of mostly carnivorous dinosaurs

Phylogeny

Genological tree

Clade

Group of organisms believed to evolve from a common ancestor

Neornithes

The avian crown group which comprises of all living birds and descendants from their most recent common ancestor

Bipedalism

Animal moves by its back two limbs (maybe need to know birds have a reversion of pubis association with forward movement)

Dinosauria

Hingelike ankles, simple filamentous feathers, bipedal posture - reptiles

Endothermic

Warm-blooded

Fossil

Remains or impressions of prehistoric organisms (skeletal remains)

Fercula

Wishbone of a bird, forked bone interclavical

Homology

Biological features including genes and their products that are descended from a feature present in common ancestor

Cretaceous-Paleogene boundary

66 million years ago, mass extinction

Jurassic Period

165-150 million years ago

Cretaceous Period

143.1 - 66 million years ago

Mesozoic ear

Age of reptiles, 251.9-66 million years ago

Ornithischia

Plant eating Dino’s covered in simple hair-like filaments called proto-feather, that are considered to be the earliest stage of feather development

Paleontology

Scientific study of the past mainly but not exclusively through the study of fossils

Speciation

Organisms that can reproduce fertile offspring together and is reproductively isolated from other organisms

Transitional fossil

Fossils that exhibit structural features between two major groups of organisms

Vestigial structures

Feature of an organism considered to have lost much or all of their original function through evolution

Extinction

Eradication of a species

Evolution

Change in a species over time

Aviation radiation

sudden increase in diversity

Adaptation

Becoming suited to an environment through natural selection

fercula

Wish bone - room for flight muscle attachment

Natural selection

Mechanism of evolution, organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided their success

Alula

“Thumb” aids in maneuvering- 3-5 feathers

Archaeopteryx

Transitional fossil - discovery provided evidence that birds evolved from reptiles, not mammals. Not a direct link to all birds.

Keel

Large, flat chest bone for flight muscle attachment

Pygostyle

Fused tailbone

Synsacrum

Fused thoracic, lumbar, sacral and vertebra with pelvic bones

Tarsometeatarsus

Fused ankle / foot bone

Tibiotarsus

Primary elongated bone in leg under femur

Scapula

Blade-like shoulder bone, backward and parallel to spine

Pneumatic bones

Hollow bones that are light but strong

Pectoralis muscle

Flight, pulls down

Supracoracoideus

Flight muscle, wing up

Air sacs

Move / store air

Syrinx

Unique, highly specialized vocal organ

Cross-current

Blood from body moves to extremities for warmth

Crop

Sac off esophagus, holds food

Proventriculus

True stomach, produces gastric acid

Gizzard

Birds for of mammals teeth, grinds food

Cloaca

Exit for poop, semen, eggs, etc

Four chambered heart

Like mammals, keeps oxygenated / deoxygenated blood seperate

Cerebrum

Largest, functions like complex behavior, learning, instinctual actions, and navigation

Cerebellum (hindbrain)

Exceptionally large in birds, coordinates skeletal muscle activity, balanced and motor control

Optic lobes

Distinctly large in birds because sight is dominant sense

Calamus

“Quill” main hollow shaft

Rachis

Upper portion of feathers shaft, supports flat branching vanes

Vane

Flat weblike surface, made up of barbs, barbules, and hooklets

Barb

Individual hair-like strand or branch that extends out from central shaft

Barbule

Extends from barb

hooklet

“Zipper” interlock adjacent branches to create the flat strong wind resistant surface. Comes off barbules

Thermoregulation

Ability to regulate temp

Feather follicle

Where feather originates

Molt

Lose / replacement of feathers

Pin feather

feather surrounded by sheath

Cover the birds body, overlap like shingles to help keep birds dry, base includes downy section for warmth

Contour feathers on their wings (coverts) shape it into an efficient airfoil by smoothing over the region where flight feathers attach to the bone

Contour feather

Airfoil

Winglike structure that produces lift and drag as it moves through the air

Wing / flight feather / remiges

Branched structure that interlocks like Velcro to create a uniform windproof surface allowing lift in flight. Typically asymmetrical with shorter less flexible leading edge that prevents midair twisting

Tail feather (rectrices)

Interlock like Velcro, arranged in a fan shape - create a uniform surface helping birds to steer in flight

Typically 6

Semiplume feather

Fluffy insulated structure with rachis, but no hooklets on the barbules. Hidden beneath other feathers, loose structures used for warmth

Down feather

Loosely branching, short or absent rachis, traps air - good to keep body heat, and also the air helps with bouyancy in waterfowl

Preening

When a bird smooths out its feathers with it beak. Birds guide barbules on their feathers into place so they fully interlock and it also distributes oil throughout the feathers to keep them healthy, flexible, and waterproof

Filoplume

Function like whiskers, short simply feathers with few barbs, rooted with nerve endings that can sense the position of contour feathers

(monitoring to detect shifts in position, pressure, or air currents)

Bristle

Stiff hairlike feathers that lack barb branches found on heads. May Help birds sense touch and vibrations / protect eyes and face

Primaries

9-10 feathers at the far end of wind, outermost 3-5 often get called “fingers” in flying raptors- fused to hand bones

Secondaries

Most of the rest of the wing, with the primaries form a trailing edge, attached to forearm (ulna)

tertials (tertiary feathers)

Couple feathers at the base, close to body. Attach to upper arm (humerus)

Structural coloration

Blue, iridescent greens and purples are generated through the way microscopic air filled structures in the feather refract light

Pigmentation definition / types

Chemical compounds that give bird feathers and skin their color by absorbing specific wavelengths of light.

Melanins (eumelanins, phaeomelanins), carotenoids, porphyrins, and specialized pigments

Melanin (2 types)

Most abundant

Eumelanins - produce deep blacks, grays, and dark browns. Provide structural strength and wear resistance to feathers

Pharomelanins - produce lighter reddish-browns, buffs, tans and pale yellows

Carotenoids

Red, oranges, and yellows

Cannot synthesize themselves

Acquired by consuming plans, algea or prey

2X. Flamingo and crustaceans

Porphyrins

Create flowing bright reds browns and greens

Psittacofulvins

Unique pigment group synthesized exclusively by parrots - reds oranges and yellows