Evolutionary History of Mammals Flashcards
The study of animals constituting Class Mammalia/Synapsida
Mammalogy
Man whose evolutionary taxonomy classification informs our classification today, uses Neo-Darwinian Synthesis
George Gaylord Simpson
Combination of Mendelian genetics and Darwinian theory (natural selection)
Neo-Darwinian Synthesis
Two subclasses of Mammalia
- Prototheria
2. Theria
Subclass of egg-laying mammals
Prototheria
One order of Subclass Prototheria
Monotremata
Subclass of mammals that give live birth
Theria
Two infraclasses of Subclass Theria
- Metatheria
2. Eutheria
Infraclass of marsupials
Metatheria
Infraclass of placental mammals
Eutheria
Four superorders of Infraclass Eutheria
- Afrotheria
- Xenarthra
- Euarchotoglires
- Laurasiatheria
Superorder of tenrecs, aardvarks, elephants, manatees
Afrotheria
Superorder of armadillos, sloths, anteaters
Xenarthra
Two grandorders of Superorder Euarchoglires
- Archonta
2. Glires
Grandorder of primates, colugos, treeshrews
Archonta
Grandorder of rabbits, rodents
Glires
Four grandorders of Superorder Laurasiatheria
- Lipotyphla
- Ferae
- Euugulata
- Chiroptera
Grandorder of shrews, hedgehogs
Lipotyphla
Grandorder of carnivores, anteaters
Ferae
Grandorder of horses, pigs, deer, whales
Euungulata
Grandorder of bats
Chiroptera
Mammals are part of a group called
Synapsids
Era with oldest fossils of synapsids
Late Paleozoic
No openings in skull behind eye
Anapsid
Examples of anapsids
Turtles, amphibians
Single opening in the skull behind each eye
Synapsid
Two openings in skull behind each eye
Diapsid
Examples of diapsids
Reptiles, birds
Openings in the skull mean more space for increased
Brain size
Mammals and reptiles both arose from the
Ammniotes
Early mammal-like amniotes; large-bodied synapsids with sail supported by vertebrae
Pelycosaurs
Late mammal-like amniotes; mid- to large-bodied, synapsid skull, differentiated teeth (canines)
Therapsids
Two suborders of Therapsids
- Anomodontia
2. Theriodontia
Suborder of Therapsids that tended to be herbivorous
Anomodontia
Suborder of Therapsids that tended to be carnivorous
Theriodontia
Members of suborder Theriodontia, secondary palate arises, premolars and molar arise
Cynodonts
Three early true mammals
- Triconodonts
- Docodonts
- Multituberculates
Early true mammals, small carnivores with 3-cusp molars
Triconodonts
Early true mammals, omnivores, lower molars rectangular with prominent cusps
Docodonts
Early true mammals, small-bodied synapsids with differentiated teeth, multicusp molariform teeth, and procumbent lower incisors
Multituberculates
Teeth sticking out of lower jaw and pointing forward
Procumbent
Three lines produced by synapsids
- Steropodon
- Sinodelphys
- Juramaia
Ancestral monotreme, Australia
Steropodon
Ancestral marsupial, China
Sinodelphys
Ancestral eutherian, China
Juramaia
Point where dinosaurs go extinct and mammals start diversifying
KT Boundary
Four examples of soft anatomy mammalian synapomorphies
- Hair
- Endothermy
- Mammary glands
- Acute sense of smell
Four examples of hard anatomy mammalian synapomorphies
- Synapsid skull
- Diphyodonty and heterodonty
- Large brain
- Three middle ear ossicles