Paleo-biogeographyPaleo-biogeographyPaleobiogeography is an exciting (and re-emerging) fieldthat involves knowledge of paleo-geology, paleo-climates, paleo-vegetation, and paleo-florasWe will examine the rise of land vegetation and florasand specifically in N. America and the Great Lakesregion by using information from paleobiogeography• paleo floras - plantsmoving onto land over400 mya andbecoming thedominant set ofterrestrial organisms• modern floras -diversification of landplants and especiallyflowering plants overthe last 100 my• ice age events(Pleistocene - last 2.5my) and the assemblyof vegetation and florain Great Lakes regionduring recent times(Holocene)Paleo-biogeographyExtant Land PlantsGreen Plants are hereThe story of paleo-biogeography on earthinvolves “land plants”and so we will excludegreen algae from ourreview of extant landplantsExtant Land PlantsPhyla with “issues”!Bryophyta - bryophytes • 16,000 species• nonvascular plants, most primitive landplants, gametophyte dominant• comprising 3 main groups (now 3phyla)liverwortsmosseshornwortsExtant Land PlantsBryophyta - bryophytes hornwortsExtant Land Plants• hornworts are sister to all otherland plants• liverworts are the firstdiverging land plantsliverwortsLycopodiophyta - lycopods • 1,150 species• vascular plants, most primitivevascular plants• sporophyte dominant; free sporing• comprising 3 familiesspikemossquillwortclub mossExtant Land PlantsExtant Land Plants• lycopods sister to all other vascular plantson earthEquisetophyta - horsetails, scouring rushes • 15 species in Equisetum• vascular plants, reduced leaves, terminal sporangia• sporophyte dominant; free sporing• now considered part of the derived fern phylumExtant Land PlantsExtant Land Plants• horsetails are just funny fernsPsilophyta - whisk ferns • 6 species in two genera• vascular plants, leafless green stemmed, lateralsporangia• once considered most primitive extant land plant• now considered part of the derived fern phylumExtant Land PlantsExtant Land Plants• whisk ferns are just reduced fernsPolypodiophyta – ferns (or Pteridiophyta) • 11,000 species• diverse in habit and habitat• spores produced in specialized sporangia• now includes horsetails and whisk fernsExtant Land PlantsPinophyta - gymnosperms • 870 species• seed plants but seeds naked or exposed• often divided into 4 phylaconifersExtant Land Plants• 870 species• seed plants but seeds naked or exposed• often divided into 4 phylacycadsExtant Land PlantsPinophyta - gymnosperms• 870 species• seed plants but seeds naked or exposed• often divided into 4 phylaginkgoExtant Land PlantsPinophyta - gymnosperms • 870 species• seed plants but seeds naked orexposed• often divided into 4 phylagnetophytesExtant Land PlantsPinophyta - gymnosperms Magnoliophyta - angiosperms, floweringplants• 275,000 species• tremendous adaptive radiation on land• seed plants with seeds encased in ovaryExtant Land PlantsExtant Land PlantsMagnoliophyta - angiosperms, floweringplants• 275,000 species• tremendous adaptive radiation on land• seed plants with seeds encased in ovary• flowers a “key innovation”?Earth TimeAge of the earth = 1 calendar year4.6 billion years = 365 days Earth forms at 4.6 bya= January 1, 12:00 a.m.A different perspective before takinga look at the rise and fall of florasand faunas through time . . .First evidence of life? - 3.8 byaOldest fossils, cyanobacteria- 3.5 bya= late March (1/4 of earth time )Age of the earth = 1 calendar year4.6 billion years = 365 days Stromatolites - CaCO3 ppt by cyanobacteria= photosynthesis!Earth TimeO2 accumulates in atmosphere -2.0 bya= late July (>1/2 of earth time)Age of the earth = 1 calendar year4.6 billion years = 365 days CO2 + H2OStarch+O2reducingatmosphereoxidizingatmosphereanaerobeextinctionaerobeevolutionEarth TimeFirst eukaryotes - 1.5 bya= early September (2/3 of earthtime gone)Age of the earth = 1 calendar year4.6 billion years = 365 days Earth TimeFirst abundant fossils in Cambrian“explosion” - 560 million yaMany phyla of animals= early NovemberAge of the earth = 1 calendar year4.6 billion years = 365 days Burgess ShaleEarth TimeFirst land life in Ordovician - 460mya (a liverwort?)= November 15 (7/8ths of earthtime gone!)Age of the earth = 1 calendar year4.6 billion years = 365 days Spore TetradEarth TimeFirst flowering plant - 135 mya =December 22Age of the earth = 1 calendar year4.6 billion years = 365 days Earth TimeEarliest civilization of Homosapiens and assembling of GreatLakes flora - 13,000 ya= December 31, 11:59 p.m.Age of the earth = 1 calendar year4.6 billion years = 365 days Conifers enter Great Lakes regionEarth TimeGeological Time Scale - the Fossil RecordPaleobiogeography relies not only oncorrect identification of fossils but also onsequential strata of rock or alluvial matterthat can be dated - such as in the GrandCanyonIn such cases, detailed chronologies offossil taxa can be assembled and,importantly, compared to fossil beds inother regions of the worldGeological Time Scale - the Fossil RecordGeological Time Scale - the Fossil Recordland plant study - andtherefore all of land life -begins around 460 mya in thePaleozoic Era of thePhanerozoic (“visible”) Eonland plant study - andtherefore all of land life -begins around 460 mya in thePaleozoic Era of thePhanerozoic (“visible”) Eon• begin with the CambrianPeriod of the Paleozoic Era• track the change ofvegetation and flora over theMesozoic and Cenozoic Eras• Basic events of each periodfrom the Cambrian to theQuaternary will be explored.Geological Time Scale - the Fossil RecordPeriods will be theimportant part of thegeological time scale toreference changes invegetation and floraGeological Time Scale - the Fossil RecordKnow1. the sequence of thePeriods,2. the general time inmillion of years,3. and importantevents and plantsCambrian Period (540 - 505 mya)• most phyla of animals seen exceptchordatesExtinct Land Plants - the Fossil Record• most phyla of animals seen exceptchordates• lime secreting algae in marine water• fungi diversifying (starting at about 600mya)• no life on land!Extinct Land Plants - the Fossil RecordCambrian Period (540 - 505 mya)But maybe so!Extinct Land Plants - the Fossil RecordCambrian Period (540 - 505 mya)Cryptospores from Upper Cambrian in Tennessee:Algal? Algal-land plant?