geologic timescale

• Stromatolites are layered mounds, columns, or sheet-like structures formed by the growth of cyanobacteria

  
• Stromatolites are the oldest known fossils on Earth, dating back 3.7 billion years
• Trilobites are an extinct group of arthropods that lived in the oceans from the Cambrian to the Permian periods, a span of about 270 million years

  
• Trilobites were the dominant marine animals during their time and are important index fossils for dating sedimentary rocks
• Fossils provide the primary source of information about the history of life on Earth
• Fossils are remnants, impressions, or traces of animals or plants from a past geological age that have been preserved in the Earth's crust
• The age of a fossil is determined through relative dating and absolute dating
• The geologic time scale is a system of classifying and measuring time in Earth's history based on the rock record and the fossil record
• The geologic time scale is divided into eons, eras, periods, and epochs, with eons being the largest units of time and epochs the smallest
• The Precambrian Eon lasted for 4.5 billion years, about 88% of Earth's history
• The Phanerozoic Eon includes the Cenozoic, Mesozoic, and Paleozoic Eras
• The Paleozoic Era marks the explosion of diverse marine life and the largest mass extinction of marine organisms
• The Mesozoic Era is known as the "Age of Reptiles" or the "Era of Dinosaurs"
• The Cenozoic Era is the "Age of Mammals" or "Recent Life" and includes the Pleistocene, Holocene, Pliocene, Miocene, Oligocene, Eocene, Paleocene epochs
• Eons Largest division of the geological time scale; half billion - 2 billion of years
• Era is a division that span time periods of tens to hundred of million of year
• Period is a division of geologic history with spans of no more than 100 million years
• Epochs is the smallest division of the geological time scale
• Cambrian period

  The era began with a spectacular burst of life. Organisms that exists here are the following:

  Echinoderms - prehistoric sponges

  Arthropods - Trilobites
• Ordovician period

  • The ocean was filled with many invertebrates
  • The first fish evolved
  • Plants colonized the land for the first time, but animals remained in the water example: moss
• Silurian period

  • In the ocean, corals appeared and fish continued to evolve
  • On land, vascular plants appeared. With special tissues to circulate water and other materials.
• Devonian Period

  • The first seed plant evolved. Seeds have a protective coat and food to help them survive.
  • Fish with lobe fins evolved. They can breathe air when they raise their heads above water.
• what period does the illustration show

  Devonian Period

  
• what period does the illustration show?

  Devonian period

  
• carboniferous period

  • Wide spreading of forest left deposits of carbon that turned into coal
  • The first amphibians & reptiles colonized land.
• what period does the illustrations show?

  carboniferous period

  
• Permian period

  • All major land masses collided to form Pangea
  • Temperatures were extreme and the climate was dry
  • Plants evolved with waxy leaves, while animals evolved with leathery skin to avoid water loss.
• Mesozoic era

  • age of reptiles
  • the era of dinosaurs
• TRIASSIC PERIOD

  • First dinosaurs colonized the land, air, and water huge seeds, ferns, conifers dominated the forests, and modern corals, fish, and insects.
  • The Pangea started to separate into Laurasia & Gondwanaland
  • It ended with another mass extinction.
• Laurasia is found in the north

  Gondwanaland is found in the south
• what does the image shows

  Triassic period

  
• Jurassic Period

  • “Golden Age of Dinosaurs”
  • The earliest birds and mammals evolved
  • First-flowering plants and new insects (pollinators)
  • Continents continued to move (Volcanic Activity)
• what period does the illustration shows?

  Jurassic period

  
• cretaceous period

  • Dinosaurs’ peak in size and distribution
  • Earth’s climate was warm; the poles lacked ice; Continents were close to their present locations
  • Ended with the extinction of the dinosaurs
• Cenozoic Era

  Age of Mammals

  “ Recent Life”
• tertiary period

  • The climate was generally warm and humid
  • Mammals evolved (Increase in size)
  • Primates evolved (human ancestors)
  • Modern rainforests and grassland appeared
  • Flowering plants and insects are numerous
• Paleocene epoch

  • First rodents, rabbits, primates, and carnivores.
  • Small mammals became larger by late Paleocene epoch
• Eocene epoch

  • Hyracotherium, echinoids abundant
  • Whale-like mammal, hyena-like mammal
• what epoch do the pictures show?

  Eocene epoch

  
• Oligocene epoch

  • Hominoids (Early Apes)
  • Mesohippus, a basic order of mammals

  present