Notes 9 - The History of Life (Part 3) Flashcards
Mesozoic Era
(250 mya - 65 mya)
-For a long time, reptile-like creatures (dinosaurs, and others) thrived and ruled the land, while reptiles and fish ruled the seas.
-200 mya next major group of vertebrates were mammals evolved from reptile-like/mammal-like group called Synapsids.
Mammals evolved from what reptile-like/mammal-like group?
Synapaids
Early mammals
-May have had some reptilian charactistics (like Platypus).
-Young are birthed in eggs but are fed with milk from mother’s glands.
-Hair instead of scales or feathers.
Mammals survived and diversified and gave up laying eggs (now had live birth), but remained in the shadows of their more successful dinosaur neighbors.
The most common types of mammals were small rodents.
200 mya during Mesozoic era
Flowering plants evolved.
150 mya during Mesozoic era
Birds evolved from dinosaurs.
What brought the Mesozoic era to an end 65 Mya?
The k/t mass extinction
What ended the reign of the dinosaurs?
A massive asteroid impact
What early mammals had some reptilian characteristics, as seen with what animal
Platypus
Mesozoic Era Timeline
At the beginning of the Mesozoic Era (250 mya), reptile-like creatures (dinosaurs, and others) thrived and ruled the land, while reptiles and fish ruled the seas. Around 200 mya the next major vertebrates were mammals. The mammals evolved from an earlier reptile-like/mammal-like group called synapsids.
Early mammals may have had
some reptilian characteristics,
as seen with the platypus.
Young are birthed in eggs but are
fed with milk from the mother’s glands. Hair instead of scales or feathers. Mammals eventually diversified and gave up laying eggs (live birth) but remained in the shadows of their more successful
dinosaur neighbors. The most common types were rodents. Also, around 200 mya flowering plants evolved. Birds evolved from dinosaurs 150 mya. The mesozoic era ended 65 mya with the K/T mass extinction astroid. Many groups survived but most dinosarus did not.
What is a dinosaur?
A massive group of different species that livedbetween about 250 and 60 mya
Species came and went during this period
Dinos are generally though of as reptilian, but many had characteristics not thought of as
reptilian, for example…
-Give live birth
-Regulate body temperature
-Feathers
Cellular life timeline
Cenozoic Era
65 mya to present
Cenozoic Era called the Age of Mammals
All mammals have
hair and feed their young with milk from mammary glands.
The earliest mammals
Like monotremes of today - eggs laying