Tens of Millions of Years

Each bead in this yellow string represents ten million years, from the Garden of Ediacara to the present. Descriptions are taken from the short version of the Great Story Timeline. Note that some of the beads are identical to those on the earlier strings that represent the same event.

	56 tens of millions of years ago (tmya) - The GARDEN OF EDIACARA is the time when the first multicellular life forms in the sea evolve distinctive body forms. Multicellularity is an innovation in which the offspring of dividing cells stay in bonded association with one another, resulting in synergies of community. (I mistakenly used the bead representing eukarya here. I'll need to find another to represent multicellular creatures.)
	54 tmya - First true ANIMALS, including jellyfish, sponges, and worms, as well as creatures with hard parts for protection (clams, trilobites) and hard parts for eating (the rasping "teeth" of snails). All of these animals live in the oceans. (This bead is clear and white and lumpy, like a jellyfish.)
	50 tmya - Earliest tabulate and rugose "corals" begin building REEFS, along with older reef-builders such as sponges and calcareous algae. (This metal bead looks like a spine, but it reminds me of a coral.)
	44 tmya - A freshwater green alga and aquatic fungus pool their talents (symbiosis), merging into the first LAND PLANTS. Life thus embarks on the adventure of weather and gravity. The continents grow green with low-lying ancestors of today's MOSSES and liverworts, which lack roots, and so must go dormant in dry conditions.
	41 tmya - in the sea arise the distant ancestors of modern SHARKS. From now on, sharks tend to be the top carnivores of the sea. (Yes, it's a fish, not a shark, but I couldn't find a shark bead.)
	36 tmya - Land plants discovered in the Devonian that by retaining the cells of previous generations and reinforcing these with lignin (WOOD), they can rise to new heights. But now TREES are abundant, having evolved independently in several different lineages (lycopods, horsetails, tree ferns), as plants compete for sunlight by overtopping their neighbors. (This is a piece of fossilized palm tree.)
	29 tmya - PANGAEA forms, a single supercontinent.
	24 tmya - At the end of Triassic, PANGAEA BREAKUP begins. First to split off is Laurasia to the north, which consists of the bedrock foundations of what will one day become North America and Eurasia. To the south, across the Tethys Sea, is the supercontinent of Gondwanaland (South America, Africa, Antarctica, Australia, India). Eventually, as the continents draw apart, Earth will bring forth six times more biodiversity than when all land was together as Pangaea. (This bead is similar to the one representing Pangaea above, but with blue and green patches distributed.)
	21 tmya - DINOSAURS, which originated in the Triassic, become the largest land animals of all time, in the form of the great herbivorous sauropods (e.g. Brachiosaurus, Diplodocus), which reach their zenith in size and diversity during the Jurassic. The first BIRDS (Archaeopteryx) with feathers and teeth, originate. The first FROGS evolve from salamander-like amphibian ancestors.
	14 tmya - Early MAMMALS diversify, but have little ecological presence and get no bigger than squirrel-size.
	6.5 tmya - The "GOLDEN AGE OF TURTLES" in North America, as turtles that could hibernate in the mud may have been the only large vertebrates in North America that made it through the Mexico impact event. This is also the birth of TURTLE ISLAND - a Native American name for North America. The inland sea that had, during the Mesozoic, flooded the middle of the continent from the Arctic to the Gulf of Mexico is now vanished, revealing a single continent. (This bead is hard to see here, but it's a fancifully decorated turtle made of pewter.)
	5.4 tmya - Old World primates evolve. (This is a gorilla, upside down.)
	3.4 tmya - SQUIRRELS originate in North America and co-evolve with NUT TREES.
	2.3 tmya - The global climate warms, but it is still very dry, providing ideal conditions for modern GRASSES to flourish. Woody/grassy savannas spread throughout the world. (Grasses - wheat, barley, rice, maize, oats - will later support the emergence of agriculture.) (This bead has green stripes)
	2.3-.5 tmya - The entire Miocene is the GOLDEN AGE OF MAMMALS, with an astounding diversity of mammalian species on land. Camels, still confined to North America, diversify into forms that resemble African gazelles and giraffes. Many kinds of peccaries fulfill the "pig" niche in North America.

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