Geologic Timescale

Precambrian

• Precambrian is the oldest and longest part of Earth's history, lasting from 4.6 billion to 541 million years ago.

• Precambrian period lasted from about 4.6 billion years ago to the beginning of the Cambrian Period, 541 million years ago, setting the stage for the explosion of life.

• The first multicelled animals appeared in the fossil record almost 600 million years ago. Known as the Ediacarans, these bizarre creatures bore little resemblance to modern life forms. They grew on the seabed and lacked any obvious heads, mouths, or digestive organs

Cambrian

• Cambrian period saw the emergence of the first predators like Anomalocaris and the first eyes in trilobites.

Permian

• Permian period was the last and longest of the Paleozoic Era, lasting 47 million years and ending in a cataclysmic extinction event.

Paleozoic

• Paleozoic Era was a time of amazing changes and diversity in life on Earth, from the first animals to the first reptiles and plants.

Ordovician

• Ordovician period had mostly barren land with some algae, fungi, and primitive plants, and the only continent was Gondwana.

Triassic

• Triassic period is the first period of the Mesozoic Era, starting 252 million years ago and ending 201 million years ago.

Four Eras

• Precambran

• Paleozoic

• Mesozoic

• Cenozoic

Paleozoic Era

• Paleozoic Era began 541 million years ago with the Cambrian explosion and ended about 252 million years ago with the end-Permian extinction, a significant event in Earth's history.

Cambrian Explosion

• Cambrian Explosion occurred about 545 million years ago, leading to a sudden diversity in life forms and the creation of major animal groups.

Mesozoic Era

• Mesozoic Era, the age of dinosaurs, lasted almost 180 million years from approximately 250 to 65 million years ago, including the Triassic, Jurassic, and Cretaceous periods.

Triassic Period

• Triassic period began 252 million years ago and ended 201 million years ago, marked by the supercontinent of Pangea and the rise of marine reptiles.

Jurassic Period

• Jurassic period succeeded the Triassic period, with major landmasses forming Pangea and the rise of marine reptiles and corals.

• plate tectonic activity picked up, and a period of continental rifting began. On the margins of the continents, shallow seas, which had dwindled in area at the end of the Permian, became more extensive

• sea levels gradually rose, the waters of continental shelves were colonized for the first time by large marine reptiles and reef building corals of modern aspect.

Cretaceous Period

• Cretaceous period was the last and longest segment of the Mesozoic Era, lasting approximately 79 million years and marked by the development of flowering plants.

• The oldest angiosperm fossil that has been found to date is Archaefructus liaoningensis found by Ge Sun and David Dilcher in China

Cenozoic era

• Cenozoic Era, known as the Age of Mammals, is the most recent era, but the diversity of life during this time is wider

Geologic Time scale

• Late Proterozoic

  • First skeletal elements

  • first soft-bodies metazoans

  • First animal traces

• Cambrian

  • First fishes

  • First Chordates

• Ordovician

  • Sudden diversification of metazoan families

• Silurian

  • First vascular land plants

• Devonian

  • First amphibians

  • Jawed fishes diversify

• Pennsylvanian

  • First reptiles

• Mississippian

  • Scale trees

  • seed ferns

• Permian

  • Major extinctions

  • Reptile diversify

• Triassic

  • First mammals

  • First dinosaurs

• Jurassic

  • First birds

  • Dinosaurs diversify

• Cretaceous

  • Extinction of dinosaurs

  • first primatees

  • first flowering plants

• Paleogene/Neogene

  • Mammals diversify

• Quaternary

  • Evolution of humans

Iba pa

• Cyanobacteria

  • First Bacteria

• Anomalocaris

  • First Predator

• Alfred Wegener

  • Continental Drift

• Pangea became gondwana and laurasia

• Ediacaran