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Oklahoma was a terrestrial environment for most of the ensuing Mesozoic era. [3] The Late Triassic Dockum Group of western Oklahoma preserved remains of archosaurs and temnospondyls, although its fossil record is restricted to a narrow region of the panhandle and is far sparser than the equivalent records in Texas, New Mexico, and Arizona. [98]
The Cambrian explosion (also known as Cambrian radiation [1] or Cambrian diversification) is an interval of time beginning approximately in the Cambrian period of the early Paleozoic, when a sudden radiation of complex life occurred and practically all major animal phyla started appearing in the fossil record.
Volcanic activity, particularly that of large igneous provinces, has been speculated to have been the cause of the environmental crisis. [3] The emplacement of the Namaqualand–Garies dykes in South Africa has been dated to 485 mya, the time at which the Cambrian–Ordovician extinction event occurred, although there remains no unambiguous evidence of a causal relationship between this ...
180 m; rising to 220 m in Caradoc and falling sharply to 140 m in end-Ordovician glaciations [8] The Ordovician ( / ɔːr d ə ˈ v ɪ ʃ i . ə n , - d oʊ -, - ˈ v ɪ ʃ ən / or-də- VISH -ee-ən, -doh-, - VISH -ən ) [ 9 ] is a geologic period and system , the second of six periods of the Paleozoic Era , and the second of twelve ...
The Great Ordovician Biodiversification Event (GOBE) was an evolutionary radiation of animal life throughout [1] the Ordovician period, 40 million years after the Cambrian explosion, [2] whereby the distinctive Cambrian fauna fizzled out to be replaced with a Paleozoic fauna rich in suspension feeder and pelagic animals.
The Cambrian (/ ˈ k æ m b r i. ə n, ˈ k eɪ m-/ KAM-bree-ən, KAYM-) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. [5] The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordovician Period 486.85 Ma.
The end-Botomian mass extinction event, also known as the late early Cambrian extinctions, refer to two extinction intervals that occurred during Stages 4 and 5 of the Cambrian Period, approximately 513 to 509 million years ago.
The northern end of the Appalachian Basin extends offshore into Lakes Erie and Ontario as far as the United States–Canada border. The province covers an area of about 185,500 square miles (480,000 km 2 ) and is 1,075 miles (1,730 km) long from northeast to southwest and between 20 and 310 miles (30 and 500 km) wide from northwest to southeast.