User:Abyssal/Portal:Quaternary

Portal topics: Activities; Culture; Geography; Health; History; Mathematics; Nature; People; Philosophy; Religion; Society; Technology; Random portal

The Quaternary prehistory Portal

Introduction

The Quaternary (/kwəˈtɜːrnəri, ˈkwɒtərnɛri/ kwə-TUR-nə-ree, KWOT-ər-nerr-ee) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ago to the present. As of 2023, the Quaternary Period is divided into two epochs: the Pleistocene (2.58 million years ago to 11.7 thousand years ago) and the Holocene (11.7 thousand years ago to today); a third epoch, the Anthropocene, has recently been proposed, but it is not officially recognised by the ICS.

The Quaternary Period is typically defined by the cyclic growth and decay of continental ice sheets related to the Milankovitch cycles and the associated climate and environmental changes that they caused. (Full article...)

Show new selections below (purge)

edit

Selected article on the Quaternary prehistory world and its legacies

The woolly mammoth (Mammuthus primigenius) was a species of mammoth, the common name for the extinct elephant genus Mammuthus. Its closest extant relative is the Asian elephant. The appearance and behaviour of this species are among the best studied of any prehistoric animal because of the discovery of frozen carcasses in Siberia and Alaska, as well as skeletons, teeth, stomach contents, dung, and depiction from life in prehistoric cave paintings. The mammoth was identified as an extinct species of elephant by Georges Cuvier in 1796.

The woolly mammoth was roughly the same size as modern African elephants. Males reached shoulder heights between 2.7 and 3.4 m (9 and 11 ft) and weighed up to 6 tonnes (6.6 short tons). Females averaged 2.6–2.9 metres (8.5–9.5 ft) in height and weighed up to 4 tonnes (4.4 short tons). The woolly mammoth was well adapted to the cold environment during the last ice age. It was covered in fur, with an outer covering of long guard hairs and a shorter undercoat. The colour of the coat varied from dark to light. The ears and tail were short to minimise frostbite and heat loss. It had long, curved tusks and four molars, which were replaced six times during the lifetime of an individual. The diet of the woolly mammoth was mainly grass and sedges. Its habitat was the mammoth steppe, which stretched across northern Eurasia and North America. (see more...)

More articles...

edit

Selected article on the Quaternary prehistory in human science, culture and economics

The history of paleontology traces the history of the effort to study the fossil record left behind by ancient life forms. Although fossils had been studied by scholars since ancient times, the nature of fossils and their relationship to life in the past became better understood during the 17th and 18th centuries. At the end of the 18th century the work of Georges Cuvier ended a long running debate about the reality of extinction and led to the emergence of paleontology as a scientific discipline.

The first half of the 19th century saw paleontological activity become increasingly well organized. This contributed to a rapid increase in knowledge about the history of life on Earth, and progress towards definition of the geologic time scale. As knowledge of life's history continued to improve, it became increasingly obvious that there had been some kind of successive order to the development of life. After Charles Darwin published Origin of Species in 1859, much of the focus of paleontology shifted to understanding evolutionary paths.

The last half of the 19th century saw a tremendous expansion in paleontological activity, especially in North America. The trend continued in the 20th century with additional regions of the Earth being opened to systematic fossil collection, as demonstrated by a series of important discoveries in China near the end of the 20th century. There was also a renewed interest in the Cambrian explosion that saw the development of the body plans of most animal phyla. (see more...)

More articles...

edit

Selected image

A neanderthal skeletal mount at the American Museum of Natural History.
Photo credit: Claire Houck

More pictures...

edit

Did you know?

Artist's restoration of an Columbian mammoth.

... that the first Columbian mammoth (artist's restoration pictured) found at the Snowmastodon site, an Ice Age fossil dig near Denver, was initially dug out by a construction worker using a bulldozer?
... that Urocyon progressus, a species of extinct fox, was formally described after two bones and a tooth were found?
... that Carletonomys, a rodent related to modern rice rats, is known only from one incomplete upper jaw from over 1 million year old silt deposits in Argentina?
... that Krijn is the common name for the first Neanderthal discovered in the Netherlands?
... that the 45,000-year-old remains of Ust'-Ishim man are the oldest modern human genome to be fully sequenced to date?