Activity

Cambrian – (570 – 500 million years ago) – The Cambrian is unique in its unusually high proportion of lagerstätte sedimentary deposits, sites of exceptional preservation where “soft” parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Cambrian biology surpasses that of some later periods. The Cambrian marked a profound change in life on Earth; prior to the Cambrian, the majority of living organisms on the whole were small, unicellular and simple; the Precambrian Charnia being exceptional. Complex, multicellular organisms gradually became more common in the millions of years immediately preceding the Cambrian, but it was not until this period that mineralized—hence readily fossilized—organisms became common.
Plate reconstructions suggest a global supercontinent, Pannotia, was in the process of breaking up early in the period
With a lack of sea ice – the great glaciers of the Marinoan Snowball Earth were long melted. the sea level was high, which led to large areas of the continents being flooded in warm, shallow seas ideal for sea life.