Zool 110 Lec: Non-Avian and Avian Dinosaurs (Lec 34)

Class Aves

what class do birds belong to

1. Saurischians 2. Ornithischians

what are the two groups of dinosaurs (other than birds)

feathers and flight

birds are defined by _____ and _____

Ornithischian Dinosaurs (Bird-Hipped)

pelvis has ilium, ischium, and pubis, the pubis points backward and runs parallel with ischium

ornithopoda (hadrosaurs), iguanodontids, heterodontosaurs, hypsilophondontids, ceratopsia, anklyosauria, stegosauria, pachycephalosauria

what are the groups of ornithischian dinosaurs

Triceratops

a ceratopsian

Pachycephalosaurus

a pachycephalosaur

Kentrosaurus

a stegosaurian

Ankylosaurus

an ankylosaur

Edmontosaurus

a hadrosaur

Saurischian Dinosaurs (Lizard Hipped)

pelvis has an ilium, ischium, and pubis, grasping hand, asymmetrical fingers, more mobile neck, pubis at an angle to the ischium

1. Sauropods 2. Theropods

what are the two major groups of Saurischian Dinosaurs

convergent evolution

the "bird-hipped" condition of ornisthischian dinosaurs is an example of what

Saurischian Dinosaurs

what group of dinosaurs are birds derived from

Notocolossus

a titanosaur

exaptation

the process in which existing structures take on new functions through descent with modification

feathers

what is exaptation within avian and non-avian dinosaurs

Ceolophysis

a theropod dinosaur

Spinosaurus

a theropod dinosaur

Deinonychus

a theropod dinosaur

Archaeopteryx

an extinct early bird, famous fossil , special fused wrist bone (lunate wrist bone), and a fused wishbone (furcula)

theropod

current phylogeny puts birds as branch of _____ dinosaurs

1. feathers 2. furcula (wishbone) 3. pneumatic (hollow) bones 4. tridactyl foot with big toe pointed backward

bird features that had already evolved in dinosaurs

65 million

how many millions of years ago did the end-cretaceous mass extinction happen

Chicxulub Crater

evidence of an impact beneath the yucatan peninsula of Mexico

1. Paleognathous 2. Neognathous

what are the two groups of birds

Paleognathous birds

Neoghnathous birds

everybody else

pygostyle

reduced tail of birds

Bird Skeletal Anatomy

keeled sternum, furcula (wishbone), no teeth, foot with three toes, hollow, air-filled (pneumatic) bones

carpometacarpus, tibiotarsus, and tarsometatarsus

what are the fused bones of the bird skeleton

contour feathers

give the bird shape (central quill that becomes the rachis/shaft, covered with barbs and barbules that form a vane)

Flight feathers

contour feathers that extend beyond the body

down feathers

feathers with no prominent rachis and no hooks on barbules, conserve heat

supracoracoideus (raises the wing) and pectoralis (depress the wing)

what are the two flight muscles

perching muscles

automatically tightening tendons close the toes down around a perch

diet

beak shapes reflect a birds ____

it is the most efficient respiratory system

what is special about the birds respiration system

homologous

is the evolutionary origin of wing structure homologous or analogous

two

how many full respiratory cycles are needed to move air through a birds respiratory system

parabronchi

allow for continuous movement of air

bird excretory system

excretion by metanephric kidneys in form of uric acid, salt glands may supplement kidneys in marine birds

Bird reproductive system

ovary typically present on left side only, enlarges during reproductive season

1. pterosaurs 2. bats 3. birds

flapping (powered) flight evolved three times independently in what three vertebrates

angle of attack and camber

what two features generate lift

1. Elliptical (songbirds) 2. High speed (ducks and swallows) 3. Dynamic soaring (albatross) 4. High-lift or passive soaring (hawks and vultures)

what are the four types of wing forms

oviparous

are birds oviparous or viviparous

deforestation, pesticides, lead poisoning, and housecats

what are the major threats to birds