Bellwork: Mon. Feb 5, 2018 A __________________________ is We are in the _______________ era. A.K.A. the Age of “_______________. ” The Age of “Reptiles” (Dinosaurs) was during the ______________ era with the height of the reign the ______________ period. The “Age of Amphibians” was during the _____________ era- or 300 m.y.a. The ____________________era covers 88% of Earth’s “history” A __________________________ is When many living things become extinct at the same time- there have been ____. http://news.bbc.co.uk/2/hi/science/nature/8496056.stm

K-T Mass extinction 65 million years ago the most recent Chicxulub impact on the Yucatán peninsula of Mexic0 is theorized to have caused the extinction of the dinosaurs. Half of the other species from the planet were destroyed by it. Mammals and birds emerged as dominant land organisms

Wyoming rock with an intermediate claystone layer that contains 1000 times more iridium than the upper and lower layers

NM CO Border: double layer of the K/T boundary is clearly seen NM CO Border: double layer of the K/T boundary is clearly seen. The lower ejecta layer is a light gray claystone that's easiest to spot and contains ejecta from the impact. The upper layer is much darker and contains the extraterrestrial iridium spike from the impactor.

Alberta, Canada

Triassic-Jurassic extinction 200 million years ago, once again almost half of earth’s species perish and dinosaurs become dominant organism for the next 135 mill yrs. Prior to this extinction, the predominant species on planet Earth were the therapsids, which were more similar to the mammals than to the dinosaurs.  This event is believed to have been caused by a massive volcanic eruption at the “Central Atlantic magmatic province” or by an astronomical event. This event happened in less than 10,000 years and occurred just before Pangaea started to break apart.