Ch. 4 - Evolution of Mammals Flashcards
What are the three eras of the geologic time scale that are relevant to mammalian evolution (in order of oldest to most recent)?
Paleozoic, Mesozoic, and Cenozoic
What are the two periods in the Cenozoic Era (in order of oldest to most recent)?
Tertiary and Quaternary
What are the 5 epochs of the Tertiary Period (in order of oldest to most recent)?
Paleocene, Eocene, Oligocene, Miocene and Pliocene
What are the two epochs of the Quaternary Period (in order of oldest to most recent)?
Pleistocene and Holocene
For mammals, the transition from this period to this period was critical
Cretaceous Period to Tertiary Period
There was increased radiation of these three groups after the End-Cretaceous mass extinction
Mammals, birds, and bony fishes
These three groups suffered huge losses in the End-Cretaceous mass extinction
Dinosaurs, marine reptiles, and marine invertebrates
During this epoch, there was significant mammal radiation, a warm climate, modern-day continent positions, and vast forests to the Arctic Circle
Paleocene Epoch
During this epoch, there was a cooler, more arid climate; a large Arctic ice cap; the first grasslands; diversification of marine mammals; and nearly all modern mammal orders were present
Pliocene Epoch
During this epoch, humans spread to the New World and to oceanic islands, and there were corresponding extinctions of large mammals, carnivores and flightless birds
Holocene Epoch
What is the taxonomic classification for mammal-like reptiles?
Class Reptilia, subclass Synapsida, Order Therapsida, suborder Cynodontia
Was suborder Cynodontia comprised mainly of herbivores?
No (mostly carnivores)
This subclass of reptiles were the dominant land reptiles for 70 million years
Synapsida
This early subclass of Class Mammalia is made up of mammals that are small and nocturnal; non-placental, diphyodont with distinct pre-molars and molars; and have increased dorso-flexion of the spine
Prototheria
This subclass of Mammalia are small carnivores and insectivores; have a single, solid mandible; have distinct inner ear ossicles; have tribisphenic molars; have upright limbs; have a secondary palate; have a reduction in ribs; and are modern mammals
Theria
