For a basic 500 square feet project in zip code 47474, the benchmark cost to Insulate Your Home ranges between $0.63 - $1.43 per square foot* . To estimate costs for your project: 1.
So in answer to your question, the oldest fossils are stromatolites, and the life forms that created those fossils were prokaryotic bacteria and algae like cyanobacteria.
What is the first living life form on earth? The first forms of life on Earth were most likely very similar to bacteria or other prokaryotic organisms. What organism provides the earliest evidence for the life on Earth?   The oldest organism ever to appear on the face of the Earth, was probably the Cyanobacteria.