The Ediacaran is a geological period of the Neoproterozoic era that spans 96 million years from the end of the Cryogenian period at 635 Mya to the beginning of the Cambrian period at 538.8 Mya. It is the last period of the Proterozoic eon as well as the last of the so-called "Precambrian supereon", before the beginning of the subsequent Cambrian period marks the start of the Phanerozoic eon, where recognizable fossil evidence of life becomes common.
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 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.
Paleontology, also spelled palaeontology or palæontology, is the scientific study of life that existed prior to the start of the Holocene epoch. It includes the study of fossils to classify organisms and study their interactions with each other and their environments. Paleontological observations have been documented as far back as the 5th century BC. The science became established in the 18th century as a result of Georges Cuvier's work on comparative anatomy, and developed rapidly in the 19th century. The term has been used since 1822 formed from Greek παλαιός, ὄν, and λόγος.
The PaleozoicEra is the first of three geological eras of the Phanerozoic Eon. Beginning 538.8 million years ago (Ma), it succeeds the Neoproterozoic and ends 251.9 Ma at the start of the Mesozoic Era. The Paleozoic is subdivided into six geologic periods :
The Precambrian is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time.
The Phanerozoic is the current and the latest of the four geologic eons in the Earth's geologic time scale, covering the time period from 538.8 million years ago to the present. It is the eon during which abundant animal and plant life has proliferated, diversified and colonized various niches on the Earth's surface, beginning with the Cambrian period when animals first developed hard shells that can be clearly preserved in the fossil record. The time before the Phanerozoic, collectively called the Precambrian, is now divided into the Hadean, Archaean and Proterozoic eons.
The Triassic is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago (Mya), to the beginning of the Jurassic 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 events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic.
Paleoclimatology is the scientific study of climates predating the invention of meteorological instruments, when no direct measurement data were available. As instrumental records only span a tiny part of Earth's history, the reconstruction of ancient climate is important to understand natural variation and the evolution of the current climate.
The Proterozoic is the third of the four geologic eons of Earth's history, spanning the time interval from 2500 to 538.8 Mya, the longest eon of the Earth's geologic time scale. It is preceded by the Archean and followed by the Phanerozoic, and is the most recent part of the Precambrian "supereon".
Synapsida is one of the two major clades of vertebrate animals in the group Amniota, the other being the Sauropsida. The synapsids were the dominant land animals in the late Paleozoic and early Mesozoic, but the only group that survived into the Cenozoic are mammals. Unlike other amniotes, synapsids have a single temporal fenestra, an opening low in the skull roof behind each eye orbit, leaving a bony arch beneath each; this accounts for their name. The distinctive temporal fenestra developed about 318 million years ago during the Late Carboniferous period, when synapsids and sauropsids diverged, but was subsequently merged with the orbit in early mammals.
Therapsida is a clade composing of a major group of eupelycosaurian synapsids that includes mammals and their ancestors and close relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more underneath the body, as opposed to the sprawling posture of many reptiles and salamanders.
The Mesoproterozoic Era is a geologic era that occurred from 1,600 to 1,000 million years ago. The Mesoproterozoic was the first era of Earth's history for which a fairly definitive geological record survives. Continents existed during the preceding era, but little is known about them. The continental masses of the Mesoproterozoic were more or less the same ones that exist today, although their arrangement on the Earth's surface was different.
The Cryogenian is a geologic period that lasted from 720 to 635 million years ago. It forms the second geologic period of the Neoproterozoic Era, preceded by the Tonian Period and followed by the Ediacaran.
Peter Douglas Ward is an American paleontologist and professor at the University of Washington, Seattle, and Sprigg Institute of Geobiology at the University of Adelaide. He has written numerous popular science works for a general audience and is also an adviser to the Microbes Mind Forum. In 2000, along with his co-author Donald E. Brownlee, he co-originated the term Rare Earth and developed the Medea hypothesis alleging that multicellular life is ultimately self-destructive.
Dawkins vs. Gould: Survival of the Fittest is a book about the differing views of biologists Richard Dawkins and Stephen Jay Gould by philosopher of biology Kim Sterelny. When published in 2001 it became an international best-seller. A new edition was published in 2007 to include Gould's The Structure of Evolutionary Theory finished shortly before his death in 2002, and recent works by Dawkins. The synopsis below is from the 2007 publication.
The Cambrian explosion is an interval of time approximately 538.8 million years ago in the Cambrian period of the early Paleozoic when there was a sudden radiation of complex life, and practically all major animal phyla started appearing in the fossil record. It lasted for about 13 to 25 million years and resulted in the divergence of most modern metazoan phyla. The event was accompanied by major diversification in other groups of organisms as well.
This timeline of natural history summarizes significant geological and biological events from the formation of the Earth to the arrival of modern humans. Times are listed in millions of years, or megaanni (Ma).
The Avalon explosion, named from the Precambrian faunal trace fossils discovered on the Avalon Peninsula in Newfoundland, eastern Canada, is a proposed evolutionary radiation of prehistoric animals about 575 million years ago in the Ediacaran period, with the Avalon explosion being one of three eras grouped in this time period. This evolutionary event is believed to have occurred some 33 million years earlier than the Cambrian explosion, which had been long thought to be when complex life started on Earth.
Attenborough: 60 Years in the Wild is a three-part BBC documentary series chronicling the 60 years career making wildlife programmes of Sir David Attenborough. The first hour-long programme, titled "Life on Camera" was broadcast on Friday 16 November 2012 on BBC Two at 9pm. The second part, "Understanding the Natural World" and third and final part, "Our Fragile Planet" were broadcast on following Fridays, 23 and 30 November 2012.
"The Lost Worlds of Planet Earth" is the ninth episode of the American documentary television series Cosmos: A Spacetime Odyssey. It premiered on May 4, 2014 on Fox, and aired on May 5, 2014 on National Geographic Channel. The episode was directed by Brannon Braga, written by Ann Druyan and Steven Soter, and featured the voice of Amanda Seyfried as geologist Marie Tharp. The episode explores the history of the Earth starting with the period of the Late Heavy Bombardment, approximately "3.8 to 4.1 billion years ago during which the Moon, Mercury, Venus, and the Earth were battered by space debris." Host Neil deGrasse Tyson then delves into the biography of the Earth, expressed "in its continents, oceans and life living on and in them, saying 'the past is another planet,'" alluding to how plate tectonics have shaped the Earth over millions of years.
