Mesozoic History

Mesozoic History - 4/10/11 1 Mesozoic Life After Permian...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 4/10/11 1 Mesozoic Life After Permian extinction • Seas were dominated by an abundance of mollusks, sea urchins, crustaceans and Fsh & reptiles. • On land, synapsids were replaced by reptiles. – crocodiles, turtles, snakes, lizards and dinosaurs Mesozoic events Mesozoic paleogeography Mesozoic is the "Age of Dinosaurs" • But also ¡ying reptiles and birds. • The earliest mammals were living in the underbrush. • At the end of the Mesozoic, ¡owering plants had become the dominant plant on land. Late Cretaceous Climate 4/10/11 2 Climate • During Mesozoic times, the poles were warm and sea levels were high - so deep ocean circulation was less vigorous. • This led to the preservation of organic Carbon in sediments by reducing the rate of O2 • Evidence supports a greenhouse world in the middle Cretaceous. But where did all this CO2 come from? Volcanoes. • NO ice in the Mesozoic! Icebox v. hothouse ocean Most dramatic change took place in the oceans • No more crinoid meadows. • In their place, the mollusks began to rapidly evolve and Fll in all the empty niches. • In contrast, the brachiopods never produced these adaptations and fell victim to shell crushing predators. • Echinoderms changed their habitat and became armored. • In place of the rugose and tabulates arose the modern or scleractinian corals. Mesozoic ocean life It was also the “Age of Ammonoids” • Great index fossils. • Pelagic w/ global distribution. • Sutures are very important for classiFcation. • Bemenites common as well. Cephalopod sutures • Nautititic • Goniatitic • Ceratitic • Ammonitic 4/10/11 3 WOW! Mesozoic gastropods Rudistid Bivalves belemnites Mesozoic echinoderms Planktic microfossils • The most important change in the oceans. • The base of the food chain 4/10/11 4 Coccolith and Foraminifera Made up of calcareous protists! Dino¡agellates & Diatoms radiolarians Phytoplankton abundance Marine Vertebrates • Cephalopods were the most common swimming animals, • but there was a huge radiation of Fsh....
View Full Document

This note was uploaded on 01/23/2012 for the course GEOL 102 taught by Professor Kysar during the Spring '06 term at George Mason.

Page1 / 15

Mesozoic History - 4/10/11 1 Mesozoic Life After Permian...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online