Quantcast

Geologic time scale Reference Libraries

Page 1 of about 20 Articles
Palaeovespa
2014-04-18 16:08:43

Palaeovespa is a genus of wasps that holds seven species, all of which are extinct. Two of the species were discovered in Baltic amber deposits from Europe dating back to the middle Eocene era, while the other five were found in Florissant Formation amber from the Priabonian stage era in Colorado in the United States. This genus, and four of its species, was first described in 1906 by Dr....

Australopithecus africanus
2013-11-29 10:55:07

Australopithecus africanus was an early hominid, an australopithecine that lived between roughly 3.03 and 2.04 million years ago in the later Pliocene and early Pleistocene. Au. africanus was of slender build and was thought to have been a direct ancestor of modern humans. Fossil remains signify that Au. africanus was considerably more like modern humans that Au. afarensis, with a more...

Tenontosaurus
2013-01-29 09:53:30

Image Caption: Head of Tenontosaurus, Institut de paléontologie humaine, Paris, France. Credit: Rémih/Wikipedia (CC BY-SA 3.0) Tenontosaurus, meaning “sinew lizard”, is a genus of medium to large sized ornithopod dinosaur. The genus is known from the late Aptian to Albian ages of the middle Cretaceious period sediments of western North America, dating roughly between 115 to 108 million...

Neoproterozoic
2012-11-18 19:10:56

The Neoproterozoic is the third of three subdivisions of the Proterozoic Eon (occurring from 1 billion years ago to 542 million years ago). This terminal era of the Proterozoic is itself divided into three sub-periods called the Tonian, Cryogenian, and Ediacaran Periods. The most severe glaciation known in the geologic record occurred during the Cryogenian Period, when ice sheets reached the...

Paleoproterozoic
2012-11-18 19:08:04

The Paleoproterozoic is the first of three subdivisions of the Proterozoic Eon (occurring from 2.5 billion to 1.6 billion years ago (Ga). This period is marked by the first stabilization of the continents, and also when cyanobacteria--a type of bacteria that uses biochemical processes of photosynthesis to produce oxygen--evolved. Experts have found paleontological evidence that during at...

Archean
2012-10-22 14:17:38

The Archean (formerly Archaeozoic) is a geologic eon between the Hadean and Proterozoic eons. The Archean Eon begins at roughly 3.8 billion years ago (Ga) and ends at about 2.5 Ga. But unlike all other geological ages, which are based on stratigraphy, The Archean eon is defined chronometrically. The lower boundary of 3.8 Ga has also not been officially recognized by the International Commission...

Hadean Eon
2012-06-26 19:51:17

The Hadean is the unofficial geological period of time that lies just before the Archean time period. The Hadean began with the formation of the Earth roughly 4.5 billion years ago (Ga) and ended about 3.8 Ga; the latter date varies according to different sources. Hadean is derived from Hades, Greek for “underworld,” referring to the hellish conditions on the planet at the time. The term...

Sharpirhynchia sharpi
2014-01-12 00:00:00

Sharpirhynchia sharpi is a species of extinct brachiopod named after fossil collector Samuel Sharp (1814-1882). This species lived during the Lower Bathonian of the Middle Jurassic Period. It is found only in the United Kingdom, and numerous specimens have been taken from several sites, the first from Limekiln Quarry in Northampton, England. S. sharpi is roughly a half-inch long, with a...

Atrypa
2014-01-12 00:00:00

Atrypa (lampshell) is an extinct genus of brachiopod from the Late Ordovician stage (444 million years ago) to the Carboniferous stage (318 mya). It occurs abundantly as fossils in marine rocks. Fossils have been found on all continents except Antarctica. This animal has distinctive concentric growth lines and is unusual in that in some Devonian beds there are numerous remains of the pedicle...

Sauroposeidon
2012-03-21 22:48:02

Sauroposeidon, meaning “earthquake god lizard,” is a genus of sauropods dinosaur from the Aptian and Albian ages of the Early Cretaceous Period (110 million years ago). It was discovered in the southeast region of Atoka County, Oklahoma, not far from the border of Texas, in a claystone outcrop. The fossils were initially misidentified as pieces of petrified wood when they were found in...

Word of the Day
ramage
  • Boughs or branches.
  • Warbling of birds in trees.
Related