Vertebrates 1 Flashcards
Approximately … of animals are vertebrates
1%
Around half of vertebrates are … and half are …
amniotes, fish (mainly actinopterygiii)
The amniotes and the non-amniotes separated in the…
late Devonian
How many orders of mammals are there?
27
How many orders of birds are there?
41
How many reptile orders are there?
4
How many amphibian orders are there?
3
There is … wherever you look on the phylogenetic tree
asymmetry
- e.g numbers of orders, number of species within each order or group (half of all bird species are passerines yet this is only 1 of 41 orders)
550MYA there were…
separate continents
300MYA there was…
one single continent called pangaea, formed from the merging of other continents through continental drift - pangaea is the main birthplace of terrestrial vertebrates
150MYA…
pangaea broke apart
The number of vertebrate species reached a maximum around…
12 million years ago
What is the smallest vertebrate?
Paedophryne amauensis - 7mm long frog
What is the largest vertebrate?
Blue whale - 33m
What depth have snailfish been found at?
8000m
Barheaded geese have been seen flying…
over the Himalayas at over 8000m of altitude
What is the fastest reproducing vertebrate?
Killifish - life cycle takes 2 weeks
… animals are usually vertebrates as an … … existence requires different feeding modes
large, energetically expensive
Most vertebrates … … whereas some … … to … …
lay eggs, give birth, live young
Vertebrates play important … roles, and are often at the … of most … chains
ecological, top, food
We know much more about vertebrates than invertebrates as they have been studied more for longer.
Correct
Give an e.g. of convergent evolution (analagous characteristics)
Shark, ichthyosaur, dolphin
Give an example of divergent evolution (homologous characteristics)
Human hand, horse hoof, dolphin fin, bat wing
For each living species of vertebrate there may be as many as … extinct species
100