Death may Die
This most ancient of times towards the end of the Precambiran doesn’t have much to speak of until the Tonian Period. At the start of the Neoproterozoic Era, an intelligent species arrives on the Earth. Their civilization would endure on the Earth for nearly a billion years (stopping short of the era of humans by about twenty million years). Modern archaeologists refer to them as the Old Ones, for they are the eldest intelligences on Earth.
They landed in Rodinia, the major supercontinent of the time. They constructed a city at their landing spot. This city would fall and rise again under the Old Ones, but it was practically sacred to them. Today the city is known as Kadeth, and its ruin remains thirty miles east and one hundred miles south of Dome Argus. It’s from that site that we have a pictorial history of the Earth.
Unfortunately, the time they left those pictorial records was long after this point (relatively close to our own era), and much of their history was mythical. They believed that they actually physically flew from some other world to this one. Evidence, including the fact that they couldn’t repeat the feat to make war with SFS, indicates that they used some form of space craft.
What is clear is that they had heavy emphasis on biotechnology. SFS and Old One pictorial records confirm this. Their manipulations affected much of evolution on Earth. It seems clear that the majority of terrestrial evolution occurred of its own accord, but several major events occurred due to their interventions over time. They may have also attempted to cool the Earth. It would appear that the Old Ones preferred cold environments, and they may have attempted to sustain a Snowball Earth.
At this time, it seems that most of their biomechanism was single-cellular, although the pictorial record depicts these ancient Old Ones as having large, polymorphous biocomputers designed for industrial use. These biocomputers could operate construction by forming themselves into shapes conducive to the construction effort. However, these were likely artifacts of later development. At this time, the Old Ones seemed to confine themselves, either of need or of choice, to single-celled operational platforms.