Portal:Cretaceous

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

The Cretaceous Portal

Shantungosaurus-v4.jpg

Introduction

The Cretaceous ( /krəˈtʃəs/ krə-TAY-shəs) is a geological period that lasted from about 145 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 geological period of the entire Phanerozoic. The name is derived from the Latin creta, "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation Kreide.

The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth by the end of the Cretaceous, coincident with the decline and extinction of previously widespread gymnosperm groups. (Full article...)

Selected article on the Cretaceous world and its legacies

Artist's reconstruction of Heterodontosaurus.
Heterodontosauridae ("different-toothed lizards") is a family of early ornithischian dinosaurs that were likely among the most basal (primitive) members of the group. Although their fossils are rare, they lived around the globe beginning in the late Triassic Period, and a few late-surviving species persisted into the Early Cretaceous.

Heterodontosaurids were fox-sized dinosaurs less than 2 meters (6.6 ft) in length, including a long tail. They are known mainly for their characteristic teeth, including enlarged canine-like tusks and cheek teeth adapted for chewing, analogous to those of Cretaceous hadrosaurids. Their diet was herbivorous or possibly omnivorous. (see more...)

Did you know?

Cycadeoidea marylandica - National Museum of Natural History - IMG 1978.JPG

Need help?

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

Consider asking it at the Wikipedia reference desk.

Selected image

Fossil of the Early Cretaceous ammonoid Mortoniceras inflatum

A fossil shell of the ammonoid Mortoniceras inflatum. The shell dates back to the Albian age (100.5–~113.0 million years ago) of the Early Cretaceous epoch and is about 20 cm in diameter. It was collected near Ndumu, South Africa and is exhibited by the Museum für Naturkunde in Berlin.
Photo credit: H. Zell

Selected article on the Cretaceous in human science, culture or economics

Geologic map of the US state of Georgia.
The geologic map of Georgia (a state within the United States) is a special-purpose map made to show geological features. Rock units or geologic strata are shown by colors or symbols to indicate where they are exposed at the surface. Structural features such as faults and shear zones are also shown. Since the first national geological map, in 1809, there have been numerous maps which included the geology of Georgia. The first Georgia specific geologic map was created in 1825. The most recent state-produced geologic map of Georgia, by the Georgia Department of Natural Resources is 1:500,000 scale, and was created in 1976 by the department's Georgia Geological Survey. It was generated from a base map produced by the United States Geological Survey. The state geologist and Director of the Geological Survey of Georgia was Sam M. Pickering, Jr. Since 1976, several geological maps of Georgia, featuring the state's five distinct geologic regions, have been produced by the federal government. (see more...)

Geochronology

Epochs - Early Cretaceous - Late Cretaceous
Stages - Berriasian - Valanginian - Hauterivian - Barremian - Aptian - Albian - Cenomanian - Turonian - Coniacian - Santonian - Campanian - Maastrichtian
Events - Cambrian–Ordovician extinction event - Great Ordovician Biodiversification Event - Taconic orogeny - Late Ordovician glaciation - Alice Springs Orogeny - Ordovician–Silurian extinction event

Landmasses - Baltica - Gondwana - Laurentia - Siberia
Bodies of water - Iapetus Ocean - Khanty Ocean - Proto-Tethys Ocean - Rheic Ocean - Tornquist Sea - Ural Ocean
Animals - Articulate brachiopods - Bryozoans - Cornulitids - Crinoids - Cystoids - Gastropods - Graptolites - Jawed fishes - Nautiloids - Ostracoderms - Rugose corals - Star fishes - Tabulate corals - Tentaculitids - Trilobites
Trace fossils - Petroxestes - Trypanites
Plants - Marchantiophyta

Fossil sites - Beecher's Trilobite Bed - Walcott–Rust quarry
Stratigraphic units - Chazy Formation - Fezouata formation - Holston Formation - Kope Formation - Potsdam Sandstone - St. Peter Sandstone

Researchers - Charles Emerson Beecher - Charles Lapworth - Charles Doolittle Walcott
Culture - Animal Armageddon - List of creatures in the Walking with... series - Sea Monsters

Quality Content

Things you can do


Here are some tasks awaiting attention:

Current Cretaceous FACs - none currently

Related content

Associated Wikimedia

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