Portal:Mesozoic

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Introduction

The Mesozoic Portal

Diplodocus longus(2).jpg

The Mesozoic Era ( /ˌmɛz.əˈz.ɪk, ˌmɛz.-, ˌmɛs-, ˌm.zə-, -z-, ˌm.sə-, -s-/ mez-ə-ZOH-ik, mez-oh-, mess-, mee-zə-, -⁠zoh-, mee-sə-, -⁠soh-), also called the Age of Reptiles and the Age of Conifers, is the second-to-last era of Earth's geological history, lasting from about 252 to 66 million years ago and comprising the Triassic, Jurassic and Cretaceous Periods. It is characterized by the dominance of archosaurian reptiles, like the dinosaurs; an abundance of conifers and ferns; a hot greenhouse climate; and the tectonic break-up of Pangaea. The Mesozoic is the middle of 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 well-documented 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 era witnessed the gradual rifting of the supercontinent Pangaea into separate landmasses that would move into their current positions during the next era. 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. The flowering plants appeared in the early Cretaceous Period and would rapidly diversify throughout the end of the era, replacing conifers and other gymnosperms as the dominant group of plants. (Full article...)

Selected article on the Mesozoic world and its legacies

Artist's restoration of Gorgosaurus libratus.
Gorgosaurus is a genus of tyrannosaurid theropod dinosaur that lived in western North America during the Late Cretaceous Period, between about 76.6 and 75.1 million years ago. Fossil remains have been found in the Canadian province of Alberta and possibly the U.S. state of Montana. Paleontologists recognize only the type species, G. libratus, although other species have been erroneously referred to the genus.

Like most known tyrannosaurids, Gorgosaurus was a bipedal predator weighing more than two metric tons as an adult; dozens of large, sharp teeth lined its jaws, while its two-fingered forelimbs were comparatively small. Gorgosaurus was most closely related to Albertosaurus, and more distantly related to the larger Tyrannosaurus. Some experts consider G. libratus to be a species of Albertosaurus; this would make Gorgosaurus a junior synonym of that genus.

Gorgosaurus lived in a lush floodplain environment along the edge of an inland sea. It was an apex predator (meaning that it was at the top of its food chain), preying upon abundant ceratopsids and hadrosaurs. In some areas, Gorgosaurus coexisted with another tyrannosaurid, Daspletosaurus. Although these animals were roughly the same size, there is some evidence of niche differentiation between the two. Gorgosaurus is the best-represented tyrannosaurid in the fossil record, known from dozens of specimens. These plentiful remains have allowed scientists to investigate its ontogeny, life history and other aspects of its biology. (see more...)

Selected article on the Mesozoic in human science, culture and economics

Oil shale.
Oil shale geology is a branch of geologic sciences which studies the formation and composition of oil shales–fine-grained sedimentary rocks containing significant amounts of kerogen, and belonging to the group of sapropel fuels. Oil shale formation takes place in a number of depositional settings and has considerable compositional variation. Oil shales can be classified by their composition (carbonate minerals such as calcite or detrital minerals such as quartz and clays) or by their depositional environment (large lakes, shallow marine, and lagoon/small lake settings). Much of the organic matter in oil shale is of algal origin, but may also include remains of vascular land plants. Three major type of organic matter (macerals) in oil shale are telalginite, lamalginite, and bituminite. Some oil-shale deposits also contain metals which include vanadium, zinc, copper, uranium.

Most oil shale deposits were formed during Middle Cambrian, Early and Middle Ordovician, Late Devonian, Late Jurassic, and Paleogene times through burial by sedimentary loading on top of the algal swamp deposits, resulting in conversion of the organic matter to kerogen by diagenetic processes. The largest deposits are found in the remains of large lakes such as the deposits of the Green River Formation of Wyoming and Utah, USA. Oil-shale deposits formed in the shallow seas of continental shelves generally are much thinner than large lake basin deposits. (see more...)

Selected image

Did you know?

Artist's restoration of Pakasuchus kapilimai.

Related portals

Topics

Geochronology - Triassic (Early - Middle - Late) - Jurassic (Early - Middle - Late) - Cretaceous (Early - Late)

Mesozoic landmasses - Pangaea - Gondwana - Laurasia - Africa - North America - South America - Antarctica - Asia - Australia - Europe - Appalachia - Laramidia

Major Mesozoic events - Mesozoic Marine Revolution - Carnian Pluvial Event - Triassic-Jurassic extinction event - Toarcian turnover - Cretaceous Terrestrial Revolution - Western Interior Seaway anoxia - Chicxulub impact - Cretaceous-Paleogene extinction event

Triassic biota appearances - Belemnites - Crickets - Dinosaurs - Earwigs - Ichthyosauromorphs - Pseudosuchians - Pterosaurs - Sauropterygians - Testudinates

Jurassic biota appearances - Ammonitids - Ankylosaurs - Avialans - Caecilians - Carnosaurs - Caudates - Ceratopsians - Ceratosaurs - Coelurosaurs - Cryptodires - Dromaeosaurids - Equisetum - Frogs - Horse-flies - Lepidopterans - Lizards - Mammals - Ornithopods - Pterodactyloids - Sauropods - Snakeflies - Stegosaurs - Tyrannosauroids

Cretaceous biota appearances - Abalones - Anglerfishes - Ants - Bees - Catfishes - Copepods - Cormorants - Crocodilians - Flowering plants - Fowls - Geckos - Hadrosauroids - Hermit crabs - Lobsters - Mosasaurs - Ornithomimosaurs - Oviraptorosaurs - Pachycephalosaurs - Requiem sharks - Sea turtles - Snakes - Squids - Stingrays - Therizinosaurs

Fossil sites - Berlin–Ichthyosaur State Park - Petrified Forest National Park - Dinosaur National Monument - Dinosaur Valley State Park

Stratigraphic units - Chinle Formation - Elliot Formation - Ischigualasto Formation - Kimmeridge Clay - Morrison Formation - Oxford Clay Formation - Solnhofen lithographic limestone - Tendaguru Formation - Crato Formation - Dinosaur Park Formation - Djadochta Formation - Hell Creek Formation - Niobrara Formation - Two Medicine Formation - Wessex Formation - Yixian Formation

History - History of paleontology - Timeline of paleontology - Timeline of ankylosaur research - Timeline of ceratopsian research - Timeline of ceratosaur research - Timeline of dromaeosaurid research - Timeline of hadrosaur research - Timeline of ichthyosaur research - Timeline of plesiosaur research - Timeline of stegosaur research - Timeline of tyrannosaur research

Researchers - William Buckland - Edward Drinker Cope - Jack Horner - Othniel Charles Marsh - Gideon Algernon Mantell - John Ostrom - Sir Richard Owen - Harry Govier Seeley - Samuel Wendell Williston

Culture - Treatise on Invertebrate Paleontology - Vertebrate Paleontology - Walking with Dinosaurs - Jurassic Park

Quality Content

Things you can do


Here are some tasks awaiting attention:

Need help?

Do you have a question about Mesozoic that you can't find the answer to?

Consider asking it at the Wikipedia reference desk.

Associated Wikimedia

The following Wikimedia Foundation sister projects provide more on this subject:

Discover Wikipedia using portals