Cenozoic Era

Cenozoic era

66 million years ago to the present day

Divided into 3 different periods:

Climate?

Quaternary Period

Neogene Period

Paleogene Period

At the beginning of this era the polar regions had little to no ice. The last 50 million years began to cool with lower temperatures, increased alpine glaciation, a stormier climate.

2.5 million years long

42 million years long

20.5 million years long

Fun Facts:

Living Organisms?

Marine and terrestrial life flourished during this era. Some organisms that lived included many types of angiosperms, small and some large mammals, birds, reptiles, and amphibians. This era also marked the beginning of human evolution!

Shifting Tectonic Plates

Evolution of Humans

The Age of Mammals

Major events:

• Azolla event
• Paleocene-Eocene thermal maximum (PETM)
• Grande Coupure or the “Great Break"

PresentDay

Timeline

Eocene Epoch

Miocene Epoch

Pleistocene Epoch

Holocene Epoch

Beginning of era

Pliocene Epoch

Paleocene Epoch

Oligocene Epoch

Event details:

• The PETM was one of the most intense and abrupt intervals of global warming in the geological record. It occurred between the Paleocene and Eocene epochs. It consisted of the earth warming over 5 oC within just 10,000 years. This led to an increase in atmospheric CO2 levels and some organisms were unable to adapt to rapidly changing environmental conditions and became extinct.
• The Azolla event occurred during the Eocene Epoch in the Arctic Ocean. It consisted of when a freshwater carbon-fixing fern, known as Azolla, repeatedly spread across the surface forming mats of vegetation. The large quantity started using up a significant amount of the atmosphere's carbon dioxide which triggered the climate to change from a greenhouse effect to an "icehouse".
• The Grand Coupure consisted of global cooling and drops in sea level, in Eurasia, the environmental impacts led to a mass extinction of marine organisms, plants, and land animals. It occurred in between the Eocene and Oligocene Epochs.

• This era is known as the age of mammals because it is when mammals came to be a dominant and large life form, including human ancestors.
• Tectonic shifts were significant, the biggest change being the closing of the Tethys Sea with collisions such as the Alps, Zagros, and Himalayas, a collision that started about 57 million years ago, and continues today. Another significant tectonic feature that occurred in the Cenozoic of North America was the conversion of the west coast of California that went from a convergent boundary subduction zone to a transform boundary
• Hominids (human-like primates) started in eastern Africa, where the climate went from jungle to savannah. Where the fossil of "Lucy" was also found.

What do these facts entail?

The beginning:

66 million years ago is when this era began. It started with the end of the Cretaceous-Paleogene extinction event at the close of the Cretaceous period that wiped out the remaining non-avian dinosaurs. The Paleogene period is divided into three epochs, the first being the Paleocene Epoch which was 66-55 mya.

Cenozoic Era Breakdown:

• Paleogene Period: consists of 3 different epochs, the Paleocene, Eocene, and the Oligocene. This period lasted around 42 million years in total.
• Neogene Period: consists of 2 different epochs, the Miocene and the Pliocene. This period lasted around 20.5 million years in total.
• Quaternary Period: consists of 2 different epochs as well, the Pleistocene and the Holocene. Altogether this period so far has lasted around 2.5 million years but is still occurring to the present day.

References:

Brantley, Callan, et al. “2.8: Phanerozoic Eon - Cenozoic Era.” Geosciences LibreTexts, Libretexts, 9 Sept. 2023, geo.libretexts.org/Bookshelves/Geology/Historical_Geology_(Bentley_et_al.)/02%3A_A_Brief_History_of_Earth/2.08%3A_Phanerozoic_Eon_-_Cenozoic_Era. Callaghan, Michael L, and Lana Williams. “Chapter 2.” Exploring Our World Biological and Archaeological Principles of General Anthropology, Pressbooks, pressbooks.online.ucf.edu/ant2000/chapter/chapter-2/. Accessed 18 Feb. 2024. Richard E. Zeebe, Lucas J. Lourens,Geologically constrained astronomical solutions for the Cenozoic era,Earth and Planetary Science Letters,Volume 592,2022,117595,ISSN 0012-821X,https://doi.org/10.1016/j.epsl.2022.117595. Zhang, Wei et al. “A Timeline of the Cenozoic Tectonic–Magmatic–Metamorphic Evolution and Development of Ore Resources in the Himalayas.” Geological journal (Chichester, England) 58.10 (2023): 3772–3789. Web. Zimmermann, Kim Ann. “Cenozoic Era: Facts about Climate, Animals & Plants.” LiveScience, Purch, 9 June 2016, www.livescience.com/40352-cenozoic-era.html.