vertebrate Flashcards
Some of the extinct Cynodonts had no what ?
lumbar ribs
what mammalian blood vessel is homologous with the 4th branchial artery in fish ?
aorta
The articular and quadrate bones are part of the cynodants jaw what are they apart of in mammals ?
middle ear
What characterises true seals (phocidae)
hindlimbs that cannot be brough forward
where did the marsupials first evolve
north america
What is an alula ?
a group of 3 feathers inserted over the first digit of the avian forelimb
What are feathers formed from ?
epidermal cells
What is the only extant species of jawless vertebrates ? and what class are they in ?
Petromyzontoidea (lampreys)
Myxinoidea (hagfish)
Agnatha
The incubation pouch of the echidna is convergent with what ?
marsupial pouch
What are PM4/M1 with regards to felids and canids ?
carnassial pair of teeth
Monotremata exhibit maternal care through ?
lactation
What interlocks in the tetrapod vertebrae ?
zygapophyses
Name a group that is paraphyletic.
reptiles
What order are goats and sheep in ?
artiodactyla
list three common features of vertebrates
vertebral column
myomeres (muscle segments)
closed loop circulatory system
list the 5 pelagic zones in order top to bottom.
Epipelagic mesopelagic (little light) bathypelagic Abyssopelagic Hadopelagic
What is the perfect shape for locomotion ? What us the length depth ratio?
Fusiform 3:7
What are the 2 sub classes of chondrichthys?
Elasmobranchs-sharks skates rays
Holocephali-ghost sharks and rat fishes
What is the main difference between the 2 sub classes of chonrichthys ?
elasmobranchs have an upper jaw that is not fused to brain case and 5-7 gills
Holocephali have a fused upper jaw with one gill slit covered by operculum
What are the two main differences between skates and rays ?
rays have reduced dorsal fin and are viviparous
What does epicercal mean and what is the opposite of this ?
The upper lobe is longer in the caudal fine.
hypocercal
what is homologous with the dermal denticle scales
teeth
how do sharks create static lift due to the lack of swimbladder ?
Cartilage instead of bone
Storage of oil (lift does not vary with pressure)
What is the spiracle used for in sharks and rays ?
Used to provide oxygenated blood to the eye and brain and in rays it is more developed allowing it to actively pump water over gills