6 . From Meso- to Cenozoic

1. 6. From Meso- to Cenozoic Triassic 250-205Pangaea Jurassic 205-140Laurasia and Gondwana Cretaceous 140-65Formation of present day continents Hot and dryPolar regions moist and temperate Warm and dryNo ice caps at poles Very warm no ice caps at poles. Ocean temperatures about 15-20º higher than today Pangaea

2. Cretaceous 140-65Formation of present days continents Very warm no ice caps at poles. Ocean temperatures about 15-20º higher than today From Müller et al. 2008)

3. Triassic 250-205Pangaea Jurassic 205-140Laurasia and Gondwana Cretaceous 140-65Formation of present days continents Herbivores Archosauromorpha Diplodocus Sauropoda Oviraptor Therapoda Mainly Carnivores Microraptor gui Saurischia Thyranosaurus rex Paraves (Down feathers) Archaeopteryx (Flight / display feathers) Dinosauria Aves Ornithischia Iguanodon Stegosaurus Stegosauria Herbivores Ceratopsia Triceratops Carnivores Nemicolopterus crypticus Pterosauria

4. Mesozoic dinosaur diversity Recent Birds: 1200 genera Mammals: 1135 genera ACE Total 1844 genera Data from Wang, Dodson (2006), Sullivan (2006)

5. Jurassic 205-140Laurasia and Gondwana Cretaceous 140-65Formation of present days continents Basal Theropoda Archaeopteryx Avialae Confuciusornis 1 – 5 kg Yixianornis <1 – 20 kg Aves Troodon(large brain, stereoscopic sight, nocturnal < 1 kg <1 – 60 kg Down feathers Jinfengopteryx Mahakala < 1 kg ParavesFlight / display feathershomoiotherm,Pneumatic bones Rahonavisprobably flight < 1 – 50 kg Deinonychus Dromaeosauridae 10 – 80 kg Velociraptor

6. Cretaceous 140-65 Paleogene 65-23 Neogene 23- Evolution of birds Tinamiformes Struthioniformes Palaeognathae Anseriformes Galliformes Adaptive radiation Neognathae Psittaciformes Apodiformes Others Strigiformes Falconiformes Passeriformes

7. Carboni-ferous 355-290 Permian 290-250 Triassic 250-205 Jurassic 205-140 Cretaceous 140-65 Cycadophyta Gingkophyta Gingko Pinophyta Adaptive radiation Cordaitales Gnetophyta Welwitschia mirabilis Magnoliophyta Amborella trichopoda Archaefructus liaoningensis Nymphaeaceae „Dicotyls” Adaptive radiation „Monocotyls”

8. Mesozoic 250-65 Cenozoic 65- Cretaceous 140-65 Paleogene 65-23 Neogene 23- Adaptive radiation Genetic diversification Adaptive radiation Extant mammalian lineages Cetacea Cetarthiodactyla Perissodactyla Carnivora Laurasiatheria Chiroptera Adaptive radiation Rodentia Lagomorpha Tree shrews Adaptive radiation Primates Euarchontoglires Ant eaters Xenarthra Elephant shrews Afrotheria Elephants Marsupialia Monotremata

9. The rise of insects Devonian Carboniferous Permian Triassian Jurassic Cretaceous Tertiary to recent Palaeodictyoptera Odonata Ephemeroptera Dictyoptera Plecoptera Zoraptera Embioptera Isoptera In the Triassic period all extant taxa already existed Genetic diversification Dermaptera Grylloblatodea Phasmida Orthoptera Mallophaga Psocoptera Thysanoptera Heteroptera Hymenoptera Neuroptera Adaptive radiation Coleoptera Siphonaptera Genetic diversification Mecoptera Diptera Trichoptera Lepidoptera

10. The rise of holometabolous insects Jurassic Cretaceous

11. Cretaceous 140-65 Paleogene 65-23 An early bee The earliest ants An early lacewing An early weevil A weevil in amber The earliest moth A swarm of midges Photos from: http://www.fossilmuseum.net/Fossil_Galleries/Insect_Galleries_by_Order/

12. The Cretaceous –Tertiary impact K-T boundary Walter Alvarez 1940- Luis Alvarez 1911- The Chicxulub Impact structure buried beneath the Yucatan Peninsula has 150 - 300 km in diameter Age dates of melt rock in the structure have at date of 65 Ma. The K-T boundary. The arrow indicates a layer of Iridium rich ash. Iridium is rare on the surface of the earth but much more common in Chondrite meteors

13. The K-T layer is divided into two parts, the Magic Layer (3 mm thick) and the Ejecta Layer (2 cm thick). They contain • Siderophiles contain the rare Earth Elements Os, Au, Pt, Ni, Co, Pd, and Ir. Iridium (Ir) has been found in the K-T layer around the world (New Zealand, Denmark, and Italy). The layer is about 100,000-years-thick. • Tektites are abundant in the K-T layer.They are quartz grains which are vaporized under intense heat and pressure, and cool into glass beads with no crystalline structure. Tektites were probably formed during a meteorite or comet collision. • Shocked quartz - When quartz is put under extremely high pressure, it can cleave in parallel planes. Shocked quartz is found at nuclear bomb sites and known meteorite impact areas. Shocked quartz is abundant in the K-T layer. • Stishovite (Silicon Dioxide) - a form of quartz created under conditions of high heat and pressure. It is used as an indicator of meteor impact. It has been found in abnormally high abundance in the K-T layer. • Glass beads - Kenneth Miller has discovered a two-inch layer of glass beads in the K-T layer near the Bass River in New Jersey, USA, supporting Alvarez' theory.

14. Extinctions at the K-T boundary were not evenly distributed across taxa 15% of all marine families went extinct, 50 % at generic level, maybe 80-90 % of all species. Affected were mainly plankton, marine predators, and shallow water communities. 25 % of terrestrial families and 56 % at generic level went extinct. Nothing bigger than 25 kg survived (predators and herbivores). However, dinosaur diversity declined even before the impact. Probably the impact wiped out the last survivors. Unaffected were higher plants (10% extinction), mammals (rise of 20%), and birds.

15. Cretaceous and Paleogene saw • an enormous diversification of • Angiospermes • Holometabolic insects (Coleoptera, Hymenoptera, Lepidoptera, Diptera) • Mammals • Birds • Gastropods • a decline in diversity of • Gymnospermes • Brachiopods • the extinction of • Ammonites • Belemnites • Dinosaurs Global species richness of dinosaurs Data from Sullivan (2006)

16. Today’s reading The Mesozoic era: http://www.palaeos.com/Mesozoic/Mesozoic.htm http://www.palaeos.com/Mesozoic/Mesozoic2.html The Cenozoic era: http://www.palaeos.com/Cenozoic/Neogene.html http://www.palaeos.com/Cenozoic/Paleogene.html