LOWER (4.6 billion year) TIMELINE
Ga Source
4.566 Birth of Solar System, 4,566 ±2 Ma; accretion over first ~8 Ma, Earth formed over first ~120 Ma Z+R
4.02 Earth's oldest known rock (NW Territories.,Canada) TM
~3.9 Meteoritic bombardment of Moon forms major craters, many of which are later filled with mare basalt GGM; PS
3.4 First stromatolites [Onverwacht] H+
3.1 Cooling of lunar mantle ends voluminous volcanism on Moon GGM
2.5 End of oxygen-poor Archean [& start of Proterozoic] GGM
2.2 Peak of banded iron formation (95% are 1,900 to 2,500 Ma) BW
2.1 First microbial structures (Gunflint Formation [chert]) H+
1.3 Oldest megascopic algae [Belt Group] H+
1 Formation of Rodinia, oldest known supercontinent WGM
0.8 Youngest lunar volcanism (?) PS
0.6 Explosion of multicellular life [dawn of Cambrian (& Phanerozoic) time]
(see expanded timeline above)
0.17 Oldest rock known from modern sea floor [Hole 801c, E of Marianas, 162 Ma (Pringle'92)] ODP
0.13 Homo sapiens (modern) RP
0 Today
UPPER (550 million year) TIMELINE
Ma Source
530 Oldest shelled organisms; trilobites followed by other invertebrates DE
500 First vertebrates (jawless fish)? H+vE; BP
463 First land plants [(sensu lato) H+ says 440 Ma, WP 417 ??] H+vE
458 Scotese map [Late Ordovician] CS
439 First jawed fish [early Silurian; H+ 425] BP
410 First wingless insects [WP 402, H+ 387] CL
405 Iapetus ocean (ancestral-Atlantic) closed; H+vE
390 Scotese map [Early Devonian] CS
356 First amphibians; first seed plants [both late Devonian, 363 (9?] BP;BD
306 Scotese map [Late Carboniferous] CS
292? First reptiles [end Carboniferous] BP
270 Pangea break-up starts 4.6 by!
251 Massive biotic extinction (including last trilobites) [end Paleozoic] DE
237 Scotese map [Early Triassic] CS
230 First dinosaurs [H+ 245, WP 240] DE
210 Early mammals [WP 1st mammals 215] H+
200 Beginning of rifting between N. America & Africa [H+ 210 ?] H+vE
0.17 Oldest rock known from modern sea floor [Hole 801c, E of Marianas, 162 Ma (Pringle'92)] ODP
152 Scotese map [Late Jurassic] CS
150 First birds [H+vE 145, H+ 148 ?] H+vE
130 Separation of India from Australia-Antarctica [H+ 135 ?]; first flowering plants H+vE; SW
125 First placental mammals [4/'02 Science, H+vE, H+ 134] BP+
90 Australia separates from Antarctica H+
67 First primates [H+ 60] BP
66 Scotese map [K/T Boundary] CS
65 Chicxulub; last dinosaurs H+vE, H+
55 India first collides with Asia [H+ puts start at ~51 Ma] H+vE
52? First horses [52? WP 49, H+ 55] (& rodents) [H+ 45] BP
20 Main Himalayan mountain building H+
9 Red Sea opens H+vE, H+
6 First Hominids RP
4.9 Gibralter closing (& Mediterranean salinity crisis) [deleted by space constraints] H+vE
3 Panama closes; Arctic glaciation begins H+vE
0.13 Homo sapiens (modern) RP
0.018 Scotese map ["Last Glacial Maximum"] CS
0 Today
+50? Future? - projected Scotese paleogeographic map CS
Sources:
BW = Windley, 1995, "The Evolving Continents" (3rd edition), Wiley, NY
CS = Scotese paleomap project (see References)
GGM = Geology, Gems, & Minerals, 1997, SI-NMNH exhibit
H+ = Harland, et al, 1989, "A Geologic Time Scale", Cambridge Univ Press
H+vE = Haq & Van Eysinga, 1998, 5th Ed "Geologic Time Table" [poster] Elsevier Science B.V.
ODP = Ocean Drilling Program, Leg 127
PS = Spudis, 2000, "Volcanism on the Moon", in "Encyclopedia of Volcanoes", AP-San Diego
WP = Poag, 1999, "Chesapeake Invader" [impact], Princeton Univ Press
Z+R = Zanda & Rotaru, 2001, "Meteorites: their impact on science and history", Cambridge Univ Press
4.6 by! = Exhibit proposal - SI-NMNH-Paleobiology, 2003
SI-NMNH colleagues:
BD = Bill DiMichele - Paleobiology
BP = Bob Purdy - Paleobiology
CL = Conrad Labandeira - Paleobiology
DE = Doug Erwin - Paleobiology
RP = Rick Potts - Anthropology
SW = ScottWing - Paleobiology
TM = Tim McCoy - Mineral Sciences
WGM = Bill Melson - Mineral Sciences
TS 2/11/03