Jurassic

Jurassic Period
201.3–145 million years ago
Mean atmospheric O
2
content over period duration
c. 26 vol %[1][2]
(130 % of modern level
Mean atmospheric CO
2
content over period duration
c. 1950 ppm[3]
(7 times pre-industrial level)
Mean surface temperature over period durationc. 16.5 °C[4]
(3 °C above modern level)
Key events in the Jurassic
view •  • 
-205 —
-200 —
-195 —
-190 —
-185 —
-180 —
-175 —
-170 —
-165 —
-160 —
-155 —
-150 —
-145 —
An approximate timescale of key Jurassic events.
Vertical axis: millions of years ago.

The Jurassic ( k/; from Jura Mountains) was a geologic period and system that spanned 56 million years from the end of the Triassic Period 201.3 million years ago (Mya) to the beginning of the Cretaceous Period 145 Mya.[note 1] The Jurassic constituted the middle period of the Mesozoic Era, also known as the Age of Reptiles. The start of the period was marked by the major Triassic–Jurassic extinction event. Two other extinction events occurred during the period: the Pliensbachian/Toarcian event in the Early Jurassic, and the Tithonian event at the end; however, neither event ranks among the "Big Five" mass extinctions.

The Jurassic is named after the Jura Mountains within the European Alps, where limestone strata from the period were first identified. By the beginning of the Jurassic, the supercontinent Pangaea had begun rifting into two landmasses: Laurasia to the north, and Gondwana to the south. This created more coastlines and shifted the continental climate from dry to humid, and many of the arid deserts of the Triassic were replaced by lush rainforests.

On land, the fauna transitioned from the Triassic fauna, dominated by both dinosauromorph and crocodylomorph archosaurs, to one dominated by dinosaurs alone. The first birds also appeared during the Jurassic, having evolved from a branch of theropod dinosaurs. Other major events include the appearance of the earliest lizards, and the evolution of therian mammals, including primitive placentals. Crocodilians made the transition from a terrestrial to an aquatic mode of life. The oceans were inhabited by marine reptiles such as ichthyosaurs and plesiosaurs, while pterosaurs were the dominant flying vertebrates.

Etymology

The chronostratigraphic term "Jurassic" is directly linked to the Jura Mountains. During a tour of the region in 1795,[7] Alexander von Humboldt recognized the mainly limestone dominated mountain range of the Jura Mountains as a separate formation that had not been included in the established stratigraphic system defined by Abraham Gottlob Werner, and he named it "Jura-Kalkstein" ('Jura limestone') in 1799.[8][9][10][11] The name "Jura" is derived from the Celtic root *jor via Gaulish *iuris "wooded mountain", which, borrowed into Latin as a place name, evolved into Juria and finally Jura.[9][10][12]

Other Languages
Afrikaans: Jura
Alemannisch: Jura (Geologie)
asturianu: Xurásicu
azərbaycanca: Yura dövrü
বাংলা: জুরাসিক
Bahasa Banjar: Jura (pariuda)
Bân-lâm-gú: Jura-kí
беларуская: Юрскі перыяд
беларуская (тарашкевіца)‎: Юра
български: Юра
brezhoneg: Juraseg
català: Juràssic
čeština: Jura
Cymraeg: Jwrasig
español: Jurásico
Esperanto: Ĵurasio
euskara: Jurasiko
فارسی: ژوراسیک
français: Jurassique
furlan: Zurassic
Gaeilge: Iúrasach
galego: Xurásico
한국어: 쥐라기
Bahasa Indonesia: Jura (periode)
íslenska: Júra
italiano: Giurassico
Basa Jawa: Jura
қазақша: Юра кезеңі
Кыргызча: Юра мезгили
Latina: Iurassicum
latviešu: Jura (periods)
Lëtzebuergesch: Jura (Geologie)
lietuvių: Jura
Limburgs: Jura (geologie)
مازِرونی: جوراسیک
Bahasa Melayu: Jurasik
Mìng-dĕ̤ng-ngṳ̄: Jurassic
монгол: Юрийн галав
မြန်မာဘာသာ: ဂျူယက်စစ် ကာလ
Nederlands: Jura (periode)
日本語: ジュラ紀
norsk nynorsk: Juratida
occitan: Jurassic
oʻzbekcha/ўзбекча: Yura sistemasi
پنجابی: جوراسک
Piemontèis: Giuràssich
Plattdüütsch: Jura (Geologie)
polski: Jura
português: Jurássico
română: Jurasic
Scots: Jurassic
Simple English: Jurassic
slovenščina: Jura
српски / srpski: Јура
srpskohrvatski / српскохрватски: Jura (period)
suomi: Jurakausi
svenska: Jura (period)
Tagalog: Hurasiko
татарча/tatarça: Юра периоды
Türkçe: Jura Devri
українська: Юрський період
Tiếng Việt: Kỷ Jura
文言: 侏羅紀
粵語: 侏羅紀
中文: 侏罗纪