Test 1 Flashcards
Define Feathers:
• filamentous, soft in texture, flexible, lightweight structures with extraordinarily diverse functions.
• dead structures that wear easily, and they must be replaced regularly through molt.
• Feathers are essential for both temperature regulation and flight. They insulate the body, repel water, and help birds to maintain their high body temperature. Lightweight and strong, the long feathers of the wing generate lift and thrust for flight.
• The wide variety of feather colors and coloration patterns are used by birds for camouflage and for social and sexual communication.
Define Beak
• varies greatly in form and function but is always toothless and covered with a horny sheath
Define gizzard and its function:
•Birds lack teeth that chew food before swallowing. Consequently, the avian digestive system is specialized to process unmasticated food. Instead of teeth, birds have a gizzard.
• The avian gizzard—a functional analogue of mammalian molars—is a large, strong, muscular structure used primarily for grinding and digesting tough food.
Define carpometacarpus
carpometacarpus, or fused hand bones, supports and maneuvers the large and powerful primary flight feathers.
Define Tibiotarsus and Tarsometatarsus
the avian ankle joint is positioned in the middle of the foot (or tarsal) bones. On either side of the ankle, birds have unique, fused leg bones called the tibiotarsus and tarsometatarsus. For stable balance on land, a bird’s center of gravity is positioned directly over and between its feet, particularly when the bird perches, squats, or rises. The equal length of the tibiotarsus and tarsometatarsus of long-legged birds ensures this relation.
Define Hallux:
The large, reversed, opposable first rear toe, or hallux, enhances the ability of birds to grip a branch or prey item and is unique among vertebrates
Define Endothermic:
they are warm-blooded and maintain high body temperatures (40°–44°C) over a wide range of ambient temperatures.
The circulatory and respiratory systems of birds include a powerful four-chambered heart and efficient, unidirectional lungs, which deliver fuel and remove both waste and heat produced by metabolic activities.
Define egg:
that are richly provisioned with a large yolk and protected by a hard shell of calcium carbonate
Define Syrinx
The syrinx of birds is a unique sound-producing structure, and it provides birds with more complex and diverse sound production capabilities than any other animals.
(In contrast with the syrinx, the sound-producing larynx of mammals constrains mammalian vocalizations by its structural simplicity. The larynx is homologous with the avian hyoid apparatus, which became the bony tongue of birds. The syrinx evolved only after the evolution of the avian bony tongue led to selection for a new vocal sound production apparatus.)
What is structure #1
Furcula
What is structure #2
Bill/Beak
What is the structure #3
Uncinate processes
What is structure #4
Keeled sternum
What is the structure #5
Mesotarsal ankle
What is structure #6
Carpometacarpus
What is structure #7
Tibiotarsus
What is structure #8
Tarsometatarsus
What is structure #1
Ankle joint
What is structure #2
Hallux
Define Adaptive Radiation include examples:
A phenomenon where great diversity develops due to the evolution of various species adapting to different ecologies and behaviors
Examples:
Beak sizes and shapes
Leg length
Wing shape…
Define Maxilla and Trabeculae
The bones of the avian beak, jaws, and palate are an engineer’s delight. The upper mandible, or maxilla, is a flattened, hollow, bony cone reinforced internally by a complex system of bony struts called trabeculae.
These struts make the beak much stronger than a hollow mandible but add little weight.
Define Rhamphotheca
The Keratin covering on the beak
Nasofrontal hinge
Responsive for cranial kinesis
Adaptive radiation in morphology, ecology, and life history is the result of a process known as?
Evolutionary adaptation
Natural selection
is the differential survival of individual organisms with advantageous traits.
(If the traits are heritable, then survivial will result in adaptive evolutionary change among generations.
Well adapted individuals live longer and produce more offspring.)
Convergence
the independent evolution of similar adaptations in unrelated organisms
Biogeography
is the study of the geographical distributions of plants and animals. For more than a century, biogeographers have divided Earth into six major faunal regions corresponding roughly to the major continental areas.
What are the 6 major faunal regions
Nearctic, Neotropical, Palearctic, Afrotropical, Indomalayan, Australasian
Endemic
Each faunal region has its characteristic birds: so-called endemic taxa or species, which are found nowhere else, and other birds that represent major adaptive radiations of more widespread taxa
What characteristics do birds and reptiles share?
• Scales
• Lay eggs
• Skull of both articulate with the 1st neck vertebrae by means of a single ball and socket device- the Occipital Condyle
• Simple middle ear with/ one ear bone - the Stapes
•Ankle is located in the middle of the tarsal bones (foot)
Occipital Condyle
Skull of both articulate with the 1st neck vertebrae by means of a single ball and socket device
Simple middle ear with/ one ear bone
Stapes
Tarsal bones
Avifaunas
regional assemblages of bird species—are mixtures of species of varied ages and origins.
Archaeopteryx lithographica
the earliest known fossil bird
1877: Feathered reptile found fossilized in ancient coastal lagoon in Germany
Crow-sized, bipedal reptile with tiny reptilian teeth and bony tail, but also had feathers on wings and tail with a backwards pointing toe called a Hallux.
Archeopteryx’s primary (flight) feathers had asymmetrical vanes.
Vanes are the planar surfaces of feathers, on either side of the feather shaft.
Most modern birds that fly have asymmetrical vanes, especially strong fliers
Archosaurs
are a specific group of reptiles that include alligators and crocodiles, dinosaurs, and pterosaurs
All archosaurs have:
• Distinctive hole in side of skull, in front of eye socket, called antorbital fenestra
• Advanced parental care behavior
Antorbital fenestra
a distinctive hole in the side of the skull in front of the eye socket
Vanes
the planar surfaces of feathers, on either side of the feather shaft.
Phylogenetic Tree
is a diagram that depicts evolutionary relationships (a phylogeny) among organisms
• Branches represent historic species evolving through time
•Nodes are points where branches split off, indicating a speciation event producing new lineages
• Clades represent all descendents (living or extinct) with a common ancestor.
Clades
Represent all dependents (living or extinct) w/ a common ancestor
Homologs
Similarities inherited from a common ancestor
Examples:
Wings of all birds are homologs
Pygostyle
a special bone created by a fusion of the vertebrae at the tip of the tail (important for flight)
Theropods
The phylogenetic sister group to the sauropods are the bipedal, meat-eating dinosaurs called theropods, which include the famous Allosaurus, Tyrannosaurus rex, Oviraptor, and Velociraptor. Birds are living theropod dinosaurs that are most closely related to the dromaeosaurs like Deinonychus and Velociraptor and to Troodon (see Figure 2–4).
Quill knobs
Where the feathers meet the ulna
Archaeopteryx evolved in what period?
What are some of their shared characteristics with birds?
Late Jurassic period
Shared characteristics of birds and Archeopteryx:
Reversed hallux
Unserrate teeth
25 or fewer tail vertebrae
Birds evolved definitive characteristics during mesozoic period that are found in the fossil records including?
Greatly reduced tail
Eventual loss of teeth
Fused tarsometatarsus in leg
Fused carpometacarpus in wing
Changes in feathers, wings, and shoulders that allowed for advanced flight strokes
Mesozoic birds ranged in size from sparrow-like to vulture-like.
The evolution of feathers and flight
Feathers
NOT unique to birds
Were found in fossil evidence of theropod dinosaurs
Found on more than a dozen non-avian theropod dinosaurs
Feathers did not originate in concert with flight
Flight
Avian flight evolved AFTER the origin of complex, vaned feathers
Two basic theories of flight:
Arboreal (Gliding)
Cursorial (Running)
However, Archaeopteryx likely employed BOTH behaviors
Two basic theories of flight:
Arboreal (Gliding)
Cursorial (Running)
