Lecture 5 Flashcards
Tetrapods Mammals and Birds
class mamamalia
Development of hair - insulation/sensory
– Development of homeothermy
– Mammary glands - feed and take care of young
– Enlarged brain (began in therapsids) - intelligence
– Dentary-squamosal jaw articulation - three ear ossicles
do the quadrate and articular articulate in the mammal
yes!
subclasses in class mammalia
Subclass Prototheria, Subclass Theria
order in subclass prototheria
– Order Monotremata
infraclasses in subclass theria
Infraclass Metatheria
Infraclass Eutheria
order in infraclass metatheria
Order Marsupialia
orders in infraclass eutheria
Order Primates (lemurs, monkey, humans)
* Order Carnivora (cats, dogs, seals, bears)
* Order Artiodactyla (even toed ungulats-deer, moose)
* Order Perissodactyla (odd toed ungulates-horses)
* Order Cetacea (porpoises and whales)
* Order Chiroptera (bats and flying foxes)
* Order Rodentia (mice, rats, squirrels, beaver)
* Order Lagomorpha (hares and rabbits)
Order Monotremata
Class Mammalia
Subclass Prototheria
Monotremes all in Australian and New Guinea
– Duck-billed platypus and spiny echina
Traits of Monotremes:
– Oviparous – lays eggs
– Mammary glands, but no nipples
Cloaca - a common opening for the digestive and urogenital tracks
Order Marsupialia
Subclass Theria, Infraclass Metatheria
Marsupium = pouch - kangaroo
Nipples
All viviparous
Infraclass Eutheria
Class Mammalia
Subclass Theria
Eutherian Mammal traits:
– All viviparous, all form placenta
– Nipples
therian evolution is
mesozoic
earliest monotremes seen in
triassic to early jurassic in australia
earliest marsupials in
jurassic in N and S america
earliest placentals in
Cretaceous in asia
Eutherians arrived in Australasia about ___ via
5-15 million years ago; (bats, rats)
Modern mammals arose from
Therapsids
Class aves
Subclass Sauriurae, Infraclass Archaeornithes
The most representative fossil for Class Aves is Archaeopteryx.
Found in Germany and a few other places – Late Jurassic.
Infraclass Archaeornithes
Archaeopteryx lithographica, earliest bird in the fossil record - from Late Jurassic
Saurischian features:
– jaws with teeth
– small forelimbs with three claws
– long bony tail
– a head covered with scales
– body, wings, and tail covered with feathers
feathers similar to modern
birds (flight feathers), light bones
Infraclass Neornithes
class aves
Modern Avian Traits:
– Extensive air sacs – cooling, less weight, better oxygen movement in and out of lungs
– Loss of teeth – less weight
– Loss of tail – replaced by feathers
origins of flight
Possible Origins of Flight
* Cursorial Theory (Williston, 1879)
– Birds were first runners, feathers helped birds to glide.
* Arboreal Theory (Marsh, 1880)
– Birds were arboreal and feathers helped them from limb to limb or glide.
* Predatory Theory (Ostrom, 1974)
– Birds were first insect eaters and feathers were used as a net to catch insects.
origins of feathers
Feathers are modified epidermal scales found in birds and some fossil reptiles
* Functions:
– Insulation – prevent heat loss or gain
– Coloration – aposematic or cryptic
– Flight
Development of hair - insulation/sensory
– Development of homeothermy
– Mammary glands - feed and take care of young
– Enlarged brain (began in therapsids) - intelligence
– Dentary-squamosal jaw articulation - three ear ossicles
class mamamalia
yes!
do the quadrate and articular articulate in the mammal
Subclass Prototheria, Subclass Theria
subclasses in class mammalia
