Early Jurassic

E38609

The Early Jurassic was the first epoch of the Jurassic Period, marked by the recovery of life after the end-Triassic extinction and the early diversification of dinosaurs and marine reptiles.

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Statements (50)

Predicate Object
instanceOf geologic epoch
subdivision of the Jurassic Period
associatedWith initial breakup of Pangaea
intense volcanic activity in large igneous provinces
opening of the Central Atlantic Ocean
beganAfter end-Triassic mass extinction
carbonDioxideLevel higher than present atmospheric level
characterizedBy diversification of marine reptiles
dominance of gymnosperm floras
early diversification of dinosaurs
expansion of ammonites
high sea levels
radiation of bivalves
recovery of marine ecosystems
recovery of terrestrial ecosystems
warm greenhouse climate
widespread shallow epicontinental seas
climate generally warm and humid
contains Hettangian
Pliensbachian
Sinemurian
Toarcian
duration about 27 million years
endTime approximately 174.1 million years ago
firstStage Hettangian
floraIncludes conifers
cycads
ginkgophytes
seed ferns
follows Late Triassic
Rhaetian Age
includesEvent Toarcian Oceanic Anoxic Event
lastStage Toarcian
marineFaunaIncludes ammonites
belemnites
brachiopods
ichthyosaurs
plesiosaurs
oxygenLevel near or slightly below present atmospheric level
partOf Jurassic Period
precedes Middle Jurassic
recognizedBy International Commission on Stratigraphy
startTime approximately 201.3 million years ago
stratotypeDefinedBy Global Boundary Stratotype Section and Point for base of Hettangian
terrestrialFaunaIncludes early mammals
early sauropod dinosaurs
ornithischian dinosaurs
pterosaurs
theropod dinosaurs
usedIn geologic time scale

Referenced by (4)

Full triples — surface form annotated when it differs from this entity's canonical label.

Watchung Mountains geologicalPeriod Early Jurassic
breakup of Gondwana startTime Early Jurassic
Jurassic subdividedInto Early Jurassic
Jurassic Period subdividedInto Early Jurassic