Second era of the Phanerozoic Eon: ~252–66 million years ago
Mesozoic Era
251.902 ± 0.024 – 66.0 Ma
Pha.
Proterozoic
Archean
Had.
Chronology
−260 —
–
−240 —
–
−220 —
–
−200 —
–
−180 —
–
−160 —
–
−140 —
–
−120 —
–
−100 —
–
−80 —
–
−60 —
P h a n e r o z o i c
Paleozoic
M e s o z o i c
Cenozoic
Triassic
Jurassic
Cretaceous
An approximate timescale of key Mesozoic events. Axis scale: millions of years ago.
Etymology
Name formality
Formal
Nickname(s)
Age of Reptiles, Age of Conifers
Usage information
Celestial body
Earth
Regional usage
Global (ICS)
Time scale(s) used
ICS Time Scale
Definition
Chronological unit
Era
Stratigraphic unit
Erathem
Time span formality
Formal
Lower boundary definition
First appearance of the Conodont Hindeodus parvus.
Lower boundary GSSP
Meishan, Zhejiang, China 31°04′47″N119°42′21″E / 31.0798°N 119.7058°E / 31.0798; 119.7058
Lower GSSP ratified
2001
Upper boundary definition
Iridium enriched layer associated with a major meteorite impact and subsequent K-Pg extinction event.
Upper boundary GSSP
El Kef Section, El Kef, Tunisia 36°09′13″N8°38′55″E / 36.1537°N 8.6486°E / 36.1537; 8.6486
Upper GSSP ratified
1991
The Mesozoic Era[3] is the second-to-last era of Earth's geological history, lasting from about 252 to 66 million years ago, comprising the Triassic, Jurassic and Cretaceous Periods. It is characterized by the dominance of gymnosperms and of archosaurian reptiles, such as the dinosaurs; a hot greenhouse climate; and the tectonic break-up of Pangaea. The Mesozoic is the middle of the three eras since complex life evolved: the Paleozoic, the Mesozoic, and the Cenozoic.
The era began in the wake of the Permian–Triassic extinction event, the largest mass extinction in Earth's history, and ended with the Cretaceous–Paleogene extinction event, another mass extinction whose victims included the non-avian dinosaurs, pterosaurs, mosasaurs, and plesiosaurs. The Mesozoic was a time of significant tectonic, climatic, and evolutionary activity. The supercontinent Pangaea began to break apart into separate landmasses. The climate of the Mesozoic was varied, alternating between warming and cooling periods. Overall, however, the Earth was hotter than it is today.
Dinosaurs first appeared in the Mid-Triassic, and became the dominant terrestrial vertebrates in the Late Triassic or Early Jurassic, occupying this position for about 150 or 135 million years until their demise at the end of the Cretaceous. Archaic birds appeared in the Jurassic, having evolved from a branch of theropod dinosaurs, then true toothless birds appeared in the Cretaceous. The first mammals also appeared during the Mesozoic, but would remain small—less than 15 kg (33 lb)—until the Cenozoic. Flowering plants appeared in the Early Cretaceous and would rapidly diversify through the end of the era, replacing conifers and other gymnosperms (sensu lato), like ginkgoales, cycads and bennettitales as the dominant group of plants.
^Jones, Daniel (2003) [1917], Peter Roach; James Hartmann; Jane Setter (eds.), English Pronouncing Dictionary, Cambridge: Cambridge University Press, ISBN 978-3-12-539683-8
^There are several ways of pronouncing Mesozoic, including IPA: /ˌmɛzəˈzoʊ.ɪk,-zoʊ-,ˌmɛs-,ˌmiːz-,ˌmiː.s-/MEZ-ə-ZOH-ik, MEZ-oh-, MESS-, MEE-z-, MEE-s-.[1][2]
The Mesozoic Era is the second-to-last era of Earth's geological history, lasting from about 252 to 66 million years ago, comprising the Triassic, Jurassic...
approximately 145 Mya. The Jurassic constitutes the middle period of the Mesozoic Era and is named after the Jura Mountains, where limestone strata from...
the National Geographic Society in Washington. Nigersaurus was dubbed a "Mesozoic cow" in the press, and Sereno stressed that it was the most unusual dinosaur...
to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest...
Period 201.4 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction...
of the Mesozoic is an American musical group founded in Boston, Massachusetts, United States, in 1980. The music of Birdsongs of the Mesozoic is almost...
Western Interior Seaway split the continent of North America in two. In the Mesozoic era, Laramidia was an island land mass separated from Appalachia to the...
The Mesozoic marine revolution (MMR) refers to the increase in shell-crushing (durophagous) and boring predation in benthic organisms throughout the Mesozoic...
Coast consists of Triassic, Jurassic and Cretaceous cliffs, spanning the Mesozoic, documenting 185 million years of geological history. The site can be best...
was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica...
dinosaurs. Dinosaurs were the dominant terrestrial vertebrates of the Mesozoic Era, especially the Jurassic and Cretaceous periods. Other groups of animals...
birds, as well as the extinct parareptiles, dinosaurs, pterosaurs and Mesozoic marine reptiles) Synapsids (mammals as well as all their extinct relatives...
Antarctica (/ænˈtɑːrktɪkə/ ) is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded...
This list of Mesozoic birds is a comprehensive list of all Mesozoic dinosaurs that have been assigned to the clade Avialae (birds, in the broadest sense)...
Phanerozoic. The Phanerozoic is divided into three eras: the Paleozoic, Mesozoic and Cenozoic, which are further subdivided into 12 periods. The Paleozoic...
similar early mammaliaformes. A recent review of the Southern Hemisphere Mesozoic mammal fossil record has argued that triosphenic mammals arose in the Southern...
expansive facility, designed by Graham Gund Architects. Giants of the Mesozoic, on display in the atrium of Fernbank Museum, features a 123-foot (37 m)...
of films that feature non-avian dinosaurs and other prehistoric (mainly Mesozoic) archosaurs, pterosaurs, and marine reptiles such as mosasaurs and plesiosaurs...
(2002), Palaeobiogeography and Biodiversity Change: The Ordovician and Mesozoic–Cenozoic Radiations, Geological Society Special Publication, Geological...
adaptations was necessary for feeding on highly fibrous plant materials. In the Mesozoic, some theropod dinosaurs such as Tyrannosaurus rex are thought probably...
last era of the Proterozoic Eon) and ends 251.9 Ma at the start of the Mesozoic Era. The Paleozoic is subdivided into six geologic periods (from oldest...
the mud volcanoes in Kai Island, indicating Mesozoic deposition in the subsurface (Charlton, 1992). Mesozoic macrofossils were studied in Misool Island...
the largest exposure of this craton. From the Late Paleozoic to Early Mesozoic eras, North America was joined with the other modern-day continents as...
(flowering plants). It is the latest of three geological eras, preceded by the Mesozoic and Paleozoic. The Cenozoic started with the Cretaceous–Paleogene extinction...
An impact event is a collision between astronomical objects causing measurable effects. Impact events have been found to regularly occur in planetary systems...
Global Information