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15 Cards in this Set

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Review vertebrate phylogeny
Bone was the first thing to evolve in the phylogeny of veterbrates.
The first veterbrates w/ jaws was later to appear about 430 MYA.
Next great event was the transistion to living on land about 357 MYA.
And about 20 MYA the amniota and amniotic egg appeared.
Where do major features like jaws, 2 pairs of appendages, legs, lungs, amniotic eggs, mammary glands, and hair evolve on vertebrate phylogeny?
after dinos died 65 mya, they diversified into lineages of small & large herbivores, small & large predators, or marine hunters
What are jawless fishes?
Fish w/out jaws
jaws dev.-490mya
Limited to suspension feeding or deposit feeding
What are cartilaginous fishes?
over 530 mya, steamlined bodies like fish & appear to have had a skull, skeletal elements that reinforced the gills, adn a notochord made of cartilage.
What are bony fishes?
Swam with the aid of a notochord, and that they breathed and fed by gulping water and filtering it through their pharyngeal gill slits.
What are lobe-finned fishes?
It is ancestrol to tetrapod, fins differ in structure well decveloped shoulder, and full articulate joints
What fish group is thought to have given rise to terrestrail vertebrates?
How did circulatory systems evolve across vertebrate phylogeny?
closed systems are the norm in phyla that appear after vertebrates
What is the MOST diverse vertebrate class?
What is the prevailing hypothesis regardin jaw evolution?
The leading hypothesis for the orgin of the jaw proposes that natural selection acted on mutations that affected the morphology of gill arches.
What is a swim bladder; why is it important?
possesed by most bony fishes and it functions as a lung or respiratory aid instead of a hydrostatic organ
What is an amniotic egg? Why is it an important step in vertebrate evolution?
Its the synapomorphy for reptiles and mammals/ key innovation for allowing tetrapods to move on land
What are the major membrane components of an amniotic egg?
-have shell that minimizes water loss
-self contained system
-water tight shell that contains a membrane bound supply of water in a protein rich soup
(membrane bound supply of water, membrane bound supply of food, and waste sac all inclosed in leathery shell)
What goups of vertebrates have an amniotic egg (look at the phylogeny!)?
reptiles and mammals (amniotic egg is key innovation for allowing tetrapods to move on land to reproduce)
What features define the group Mammalia?
-presence of hair or fur
-have mammary glands
-facial muscles and lips
-maintain high body temps