Mark A. S. McMenamin (born c. 1957) is an American paleontologist and professor of geology at Mount Holyoke College.He has contributed to the study of the Cambrian explosion and the Ediacaran biota.. He is the author of several books, most recently Deep Time Analysis (2018) and Dynamic Paleontology (2016). His earlier works include The Garden of Ediacara: Discovering …

The Cambrian explosion, Cambrian radiation, Cambrian diversification, or the Biological Big Bang refers to an interval of time approximately in the Cambrian Period when practically all major animal phyla started appearing in the fossil record. It lasted for about 13 – 25 million years and resulted in the divergence of most modern metazoan phyla. The event was accompanied by …

Gewervelden of vertebraten (Vertebrata) vormen een onderstam van chordadieren.Gewervelde dieren kenmerken zich door de aanwezigheid van een wervelkolom.Dit zijn de prikken, vissen, amfibieën, reptielen, vogels en de zoogdieren.De gewervelden maken het grootste deel uit van de Chordata, dieren die een chorda of ruggenmergstreng hebben. Tot de Chordata behoren …

Die Triskele, auch der oder das Triskel (von griechisch τρισκελής triskelḗs, deutsch ‚dreibeinig‘), ist ein Symbol in Form von drei radialsymmetrisch angeordneten Kreisbögen, offenen Spiralen, ineinander verschachtelten Dreiecken, Knotenmustern, menschlichen Beinen oder anderen Dreifach-Formen.Weitere Bezeichnungen sind Dreibein und Triquetra.

The Bruneau-Jarbidge caldera (sometimes called a supervolcano) [citation needed] is located in present-day southwest Idaho.The volcano erupted during the Miocene, between ten and twelve million years ago, spreading a thick blanket of ash in the Bruneau-Jarbidge event and forming a caldera.Animals were suffocated and burned in pyroclastic flows within a hundred miles of the …

Greensand or green sand is a sand or sandstone which has a greenish color. This term is specifically applied to shallow marine sediment that contains noticeable quantities of rounded greenish grains. These grains are called glauconies and consist of a mixture of mixed-layer clay minerals, such as smectite and glauconite mica. Greensand is also loosely applied to any …

The timeline of the evolutionary history of life represents the current scientific theory outlining the major events during the development of life on planet Earth.Dates in this article are consensus estimates based on scientific evidence, mainly fossils.. In biology, evolution is any change across successive generations in the heritable characteristics of biological populations.

Synonyms; Pomoria Fedonkin, 1980. P. corolliformis Fedonkin, 1980; Tribrachidium heraldicum is a tri-radially symmetric fossil animal that lived in the late Ediacaran (Vendian) seas. In life, it was hemispherical in form. T. heraldicum is the best known member of the extinct group Trilobozoa. [citation needed

List of Ediacaran genera; List of Late Quaternary prehistoric bird species; List of quaternary mammalian fauna of China; List of vertebrate fauna of the Maastrichtian stage; See also. Lists of extinct animals; List of transitional fossils; Palaeontology; Prehistory

The Avalon Peninsula is a noted region for Precambrian fossils, and many Lagerstätten of the diverse Ediacaran biota are found on the peninsula. Mistaken Point is the original location of the first documented Ediacaran , Aspidella terranovica (which gets …

The Cordilleran ice sheet was a major ice sheet that periodically covered large parts of North America during glacial periods over the last ~2.6 million years. This included the following areas: Western Montana; The Idaho Panhandle; Northern Washington state down to about Olympia and Spokane; All of British Columbia; The southwestern third or so of Yukon Territory

The Long Mynd (Welsh: Cefn Hirfynydd) is a heath and moorland plateau that forms part of the Shropshire Hills in Shropshire, England.The high ground, which is common land and designated as an Area of Outstanding Natural Beauty, lies between the Stiperstones range to the west and the Stretton Hills and Wenlock Edge to the east. Much of it is owned by the National Trust, and …

The Wolstonian Stage is a middle Pleistocene stage of the geological history of Earth from approximately 374,000 until 130,000 years ago. It precedes the Eemian Stage in Europe and follows the Hoxnian Stage in the British Isles.. It is also approximately analogous to the Warthe and Saalian stages in northern Europe; the Riss glaciation in the Alps; and the Illinoian Stage …

The Paleogene (/ ˈ p eɪ l i. ə dʒ iː n,-l i. oʊ-, ˈ p æ l i-/ PAL-ee-ə-jeen, -⁠ee-oh-, PAY-lee-; also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period 66 million years ago to the beginning of the Neogene Period 23.03 Mya. It is the beginning of the …