Lecture 16 Diversity of Vertebrates Flashcards
(12 cards)
notochord
long flexible rod that provides support in vertebrates which later turns into vertebral column that allows animals to get larger
pharyngeal slits
used for filter feeding and later turns into gills and later lungs
pharyngeal jaw
the first two gill arches within a fish fused together to create a jawbone allowing for the mouth to open and close to push water over jaws
Identify the four traits that are unique to animals in Phylum Chordata, and describe the advantage of each trait.
Notochord - long, flexible rod provides support which developed into the spine
Dorsal nerve cord - hollow nerve cord develops into advanced sensory systems
Pharyngeal slits - used for filter feeding and developed into gills for more O2 intake to get big
Postanal tail - powers movement in water and balance of large animals on land
What characteristics of early fishes allowed them to become more active and start swimming up off the bottom?
Developed paired fins and jawbone
When jaws first evolved, what was their function?
Jaws were derived from modified gill arch that open and close rapidly to ventilate gills. This increased O2 intake because they could open their mouths and let water rush over their gills
How did the Placoderms shape the evolution of both sharks and bony fishes?
Sharks fulfilled their role by becoming a predatory species while bony fishes avoided them and began developing lungs to breathe more O2
What is the most diverse group of vertebrates?
Ray-finned fish
Describe how the structure of their fins allows ray-finned fishes to achieve a high level of maneuverability while swimming.
Developed swim bladders that reduce water density and individual muscles for each bone to fine tune the shape of their fins to change or maintain direction
Describe the adaptations that ray-finned fishes have to effectively feed in water.
Developed flexible oral jaw and skull and pharyngeal jaw in order to aid in their suction of water
Why would lobe-finned fishes have been more successful than ray-finned fishes when bony fish first evolved and were living in shallow water?
They developed pectoral fin bones in order to improve their locomotion regarding navigating structures within the waters
In what animal did we first see the one bone-two bone-many bone structure that is found in vertebrate forelimbs today, and what advantage did that animal gain from this bone structure?
Tiktaalik, able to go onto land
