Biogeography. Lecture 5 Alexey Shipunov Minot State University January 29, 2014 Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 1 / 34 Outline Palaeogeography Plate tectonics Most important eras and periods Cryogenian period (850–635 Mya) and Snowball Earth Ediacarian period: 635–550 Mya Cambrian period Ordovician, Silurian and Devonian: three ages of fishes Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 2 / 34 Outline Palaeogeography Plate tectonics Most important eras and periods Cryogenian period (850–635 Mya) and Snowball Earth Ediacarian period: 635–550 Mya Cambrian period Ordovician, Silurian and Devonian: three ages of fishes Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 2 / 34 Palaeogeography Plate tectonics Palaeogeography Plate tectonics Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 3 / 34 Palaeogeography Plate tectonics Mantle convection I The driving force of floating continents is a mantle convection I In ocean ridges, new ocean cortex is constantly forming and expanding I In ocean trenches and continental ridges, different plates are colliding and often forming mountains Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 4 / 34 Palaeogeography Plate tectonics Mantle convection Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 5 / 34 Palaeogeography Plate tectonics Mantle convection Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 6 / 34 Palaeogeography Plate tectonics The result of mantle convection Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 7 / 34 Palaeogeography Plate tectonics What is going on now Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 8 / 34 Palaeogeography Plate tectonics Two living examples of continental drift on U.S. territory I Yellowstone hotspot I Hawaiian hotspot Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 9 / 34 Palaeogeography Plate tectonics Yellowstone hotspot Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 10 / 34 Palaeogeography Plate tectonics Hawaiian hotspot Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 11 / 34 Most important eras and periods Cryogenian period (850–635 Mya) and Snowball Earth Most important eras and periods Cryogenian period (850–635 Mya) and Snowball Earth Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 12 / 34 Most important eras and periods Cryogenian period (850–635 Mya) and Snowball Earth Rodinia—the first super-continent I Tectonic plates formed (and will form) one continent several times I 650 Mya this continent—Rodinia was formed right over the South Pole Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 13 / 34 Most important eras and periods Cryogenian period (850–635 Mya) and Snowball Earth Cryogenian continents which formed Rodinia Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 14 / 34 Most important eras and periods Cryogenian period (850–635 Mya) and Snowball Earth Rodinia: view from South Pole Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 15 / 34 Most important eras and periods Cryogenian period (850–635 Mya) and Snowball Earth Marionan glaciation: Snowball Earth I First global glaciation was started because ice started to concentrate over the pole and increase Earth albedo (this is the positive feedback) I And because the configuration of continents blocked the equatorial warm current I And because concentration of oxygen was high but greenhouse gases (like CO2)—small I As a result, from time to time Earth was completely covered with ice sheet 1 km tall! Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 16 / 34 Most important eras and periods Cryogenian period (850–635 Mya) and Snowball Earth Star Wars Hoth—ice planet Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 17 / 34 Most important eras and periods Cryogenian period (850–635 Mya) and Snowball Earth Snowball Earth Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 18 / 34 Most important eras and periods Ediacarian period: 635–550 Mya Most important eras and periods Ediacarian period: 635–550 Mya Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 19 / 34 Most important eras and periods Ediacarian period: 635–550 Mya Rodinia breaks Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 20 / 34 Most important eras and periods Ediacarian period: 635–550 Mya Ediacarian continents Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 21 / 34 Most important eras and periods Ediacarian period: 635–550 Mya Life in Cryogenian and Ediacarian I Before: prokaryotes, included photosynthetic (cyanobacteria), then unicellular eukaryotes I Cryogenian: multicellular eukaryotes, e.g. algae I Ediacarian: first animals Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 22 / 34 Most important eras and periods Ediacarian period: 635–550 Mya Ediacarian life Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 23 / 34 Most important eras and periods Cambrian period Most important eras and periods Cambrian period Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 24 / 34 Most important eras and periods Cambrian period Cambrian map Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 25 / 34 Most important eras and periods Cambrian period Cambrian climate and life I Gradually changed from colder to warmer I Cambrian explosion: appearance of most of animal phyla with skeleton I Little or no terrestrial life I The main driver of animal evolution during Cryogenian–Cambrian was probably oxygenation of water I One theory states that pre-Cambrian ocean water was muddy and rich of organic compounds, animal filtration changed this condition Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 26 / 34 Most important eras and periods Cambrian period Cambrian life Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 27 / 34 Most important eras and periods Ordovician, Silurian and Devonian: three ages of fishes Most important eras and periods Ordovician, Silurian and Devonian: three ages of fishes Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 28 / 34 Most important eras and periods Ordovician, Silurian and Devonian: three ages of fishes Ordovician period I Climate changed from hot to glaciated (Gondwana hits the South Pole) I Marine fauna spread out, especially cephalopods, conodonts and graptolites I In the end, the first great extinction: 85% of marine species extinct Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 29 / 34 Most important eras and periods Ordovician, Silurian and Devonian: three ages of fishes Silurian period I Fluctuating climate I Prospering of marine fauna again I Land colonization started from plants and arthropods! I South Pole still in the Gondwana Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 30 / 34 Most important eras and periods Ordovician, Silurian and Devonian: three ages of fishes Silurian sea Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 31 / 34 Most important eras and periods Ordovician, Silurian and Devonian: three ages of fishes Devonian period I Moderate climate becoming warmer I Exceptionally high sea level I Greatest diversity of marine fauna in Paleozoic (especially fishes) I Terrestrial vertebrates: tetrapods appeared! Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 32 / 34 Most important eras and periods Ordovician, Silurian and Devonian: three ages of fishes Summary I Continents of Earth are constantly changing their position due to the mantle convection (“plate tectonics”) I From Cryogenian to Ordovician, super-continent Rodinia broke and climate on Earth became milder I Most of water-inhabiting animal groups appeared by Ordovician Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 33 / 34 Most important eras and periods Ordovician, Silurian and Devonian: three ages of fishes For Further Reading A. Shipunov. Biogeography [Electronic resource]. 2014—onwards. Mode of access: http://ashipunov.info/shipunov/school/biol_330 Plate tectonics. http://en.wikipedia.org/wiki/Plate_tectonics Shipunov (MSU) Biogeography. Lecture 5 January 29, 2014 34 / 34.