The Cambrian Period

Refrences:

Cambrian Period

• Secher, Andy. Travels with Trilobites : Adventures in the Paleozoic, Columbia University Press, 2022. ProQuest Ebook Central, https://ebookcentral.proquest.com/lib/ucf/detail.action?docID=6690865.
• R, Cabej, Nelson. Epigenetic Mechanisms of the Cambrian Explosion, Elsevier Science & Technology, 2019. ProQuest Ebook Central, https://ebookcentral.proquest.com/lib/ucf/detail.action?docID=5945706.

The first period of the Paleozoic Era! Took place from 541-485 million years ago.

Began with an Explosion

Breatheable?

On Land

At this time, the amount of oxygen in the environment was 60% less than what it is today, with much higher levels of carbon dioxide!

Before the Cambrian, life on Earth was not nearly as diverse and was much simpler.

Shifting continental masses cause frequent earthquakes and volcanic activity. There isn't any animal life on land yet, but there are some microbial mats near the tides.

When the Cambrian began, life rapidly diversified and evolved greatly in a short period.

Under the sea

Ended with extinction

Animal life

Oceans dominated the Earth at this time, so it only makes sense for the explosive development of life to start there. Trilobites lived through the Paleozoic, from begginging to end, and were common under the sea, along with many other invertabrates. With many ecological niches to be filled, life was exciting and bustling underwater.

Drops in speciation were affecting animals like trilobites, and as the chemistry of the ocean changed, it became harder for these creatures to adjust. Oxygen levels in the ocean had greatly dropped, which likely a cause of this mass extinction event. This caused extrinction for 60% of life at the time.

Diverse creatures of all sizes fill the ocean, finding new niches to fill. Arthropods were greatly outnumbered by soft-bodied animals, but were much better adapted. Trilobites begin to make their way on land and shallow flats. Large Anomalocaris were main predators.