Mesoproterozoic

The Mesoproterozoic is a geologic era which lasted from 1,600 million years ago (mya) to 1,000 mya.

The major events of this era are: 
the breakup of the Columbia supercontinent ~1,500 mya;
the assembly of the Rodinia supercontinent ~1,100 mya;
the evolution of sexual reproduction.

Evidence of a eukaryotic red algae, Bangiomorpha pubescens, has been identified from  ~1200 mya old rocks in the Hunting Formation (Somerset Island, Canada). This is the oldest known sexually reproducing organism and therefore the earliest known complex multicellular organism.Butterfield N.J. 2000. Bangiomorpha pubescens n. gen., n. sp.: implications for the evolution of sex, multicellularity, and the Mesoproterozoic/Neoproterozoic radiation of eukaryotes. Paleobiology 26, 386–404. 

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