Triassic+Period

8th


 * The start of the Triassic period (and the Mesozoic era) was a desolate time in Earth's history.
 * But it was also a time of **tremendous change and rejuvenation**
 * By the end of the period 199 million years ago, tectonic forces had slowly begun to split the supercontinent in two.
 * The oceans teemed with the coiled-shelled ammonites, mollusks, and sea urchins that survived the Permian extinction and were quickly diversifying. The **first corals appeared**
 * But perhaps the biggest changes came with the **evolution of dinosaurs and the first mammals** in the late Triassic, starting around 230 million years ago.
 * The global climate in the Triassic was mostly hot and dry, but the Earth became cooler and wetter as Pangaea drifted apart.

The **Triassic** is a [|geologic period] and [|system] that extends from about 250 to 200 [|Mya] (million years ago). As the first period of the [|Mesozoic Era], the Triassic follows the [|Permian] and is followed by the [|Jurassic]. Both the start and end of the Triassic are marked by major [|extinction events]. The extinction event that closed the Triassic Period has recently been more accurately dated, but as with most older geologic periods, the rock beds that define the start and end are well identified, but the exact dates of the start and end of the period are uncertain by a few million years. The Triassic began in the wake of the [|Permian–Triassic extinction event], which left the Earth's biosphere impoverished. The early half of the period witnessed life's slow recovery, while the latter half is characterized by the [|archosaurs]' rise to dominance ([|dinosaurs] did not actually become dominant until the Jurassic[|[][|4][|]]). The first true [|mammals] also evolved during the Triassic, as well as the first flying vertebrates, the [|pterosaurs]. The vast [|supercontinent] of [|Pangaea] existed until the mid-Triassic, after which it began to gradually rift into two separate landmasses, [|Laurasia] to the north and [|Gondwana] to the south. The global climate in the Triassic was mostly hot and dry, but the Earth became cooler and wetter as Pangaea drifted apart.

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