 Plants consisted mostly of green and red algae.  It is said that the first land plants evolved from algae.  Besides algae, another type of plant was moss.  There has been found evidence tetrahedral spores that are similar to those of primitive land plants, suggesting that plants invaded the land at this time.

 The Ordovician was the period of the marine animals.  Some of the animals are: primitive fish, cephalopods, corals, crinoids, and gastropods.  There are two types of cephalopods: Cloeoidea and the Nautiloidea.

 During the Ordovician, many of the landmasses were aligned in the tropics.  This likely caused the mass extinctions that characterize the end of the Ordovician period, in which 60% of all marine invertebrate genera and 25% of all families went extinct.  While also being a source of abundant fossils and in some regions major reservoir of oils and gasses.  It is the second of six periods of the Paleozoic era, lying between the earlier Cambrian period and the later Silurian period.

 Climate was fairly warm during the first few parts  From the early to middle Ordovician, the earth experienced a milder climate in which the weather was warm and the atmosphere contained a lot of moisture.  When Gondwana finally settled on the South Pole during the Late Ordovician, massive glaciers formed causing shallow seas to drain and sea levels to drop.  At the end of the Ordovician period, the climate eventually grew very warm and then, even hotter.

 Nearly all life on Earth was in oceans.  Mass extinction, in which 60% of all marine invertebrate and 25% of all families went extinct.  Large meteorite impact may have been responsible for the mass extinction marking the end of the Cambrian Period and the start of the Ordovician Period

w and- finds.com/ordovicianperiod h 880/Ordovician-period-as-discussed-in- Earth h tion/ordmass.html w an_period.aspx h about/Geology-in-the-Ordovician-Period