Exam 4 Flashcards
What class are birds in?
Aves
How many species of birds are there?
10,000
What are birds hypothesized to be very closely related to?
theropod dinosaurs
What theropod in particular is closely related to birds?
velociraptor
Why are birds thought to be so closely related to theropods?
have many skeletal characteristics in common with some theropods
Based on cladistics birds may have actually represented what?
a living dinosaur which is specialized for flight
Where are the earliest fossil birds from the Jurassic sediment from?
Germany
What is considered to be the first bird in the fossil record?
archaeopteryx
What does archaeopteryx mean?
ancient wing
What is a bird with many reptile characteristics?
archaeopteryx
What are some characteristics of archaeopteryx?
feathers
reptile head with teeth and scales
well developed tail vertebrae
What did archaeopteryx have that modern birds do not?
well developed tail with vertebrae
Why is it thought that archaeopteryx could only fly for short distances?
appeared to be relatively heavy
When did birds try to challenge the mammals for dominating the terrestrial environment?
during the tertiary period (early in Cenozoic)
What is gastornis also known as?
diatryma
What is diatryma/gastornis?
large carnivorous flightless bird
How big did diatryma/gastornis get?
7 ft in height
What are some physical characteristics of diatryma/gastornis?
fast runner
large legs and head
short wings
What kind of beak did diatryma have and what was it used for?
large hooked beak for killing prey and tearing meat
How big was the terror bird?
7 ft in height
When did terror bird occur?
about 2 million years ago
Where was terror bird found?
not America from central FL to TX
How are birds skeletal systems adapted for flight?
it is light but sturdy
Birds have pneumatic bones, what are they?
air filled cavities for the larger bones