Stromatolites are rocky structures that generally form in shallow waters from the binding of sediment by microbial biofilms. stromatolites are typically hypothesized to be formed from the presence of cells that bind these grains together. if the appearance of the stromatolites in the fossil record were to indicate the emergence of life on earth, approximately how old are the oldest stromatolites on earth? a) 2.6 billion years old b) 3.6 billion years old c) 4.6 billion years old d) 400 million years old

Approximately, the oldest stromatolites are 3.6 billion years old on earth.

Explanation:

Stromatolites is not only oldest earths fossil but conspiracy in that they are singular visual portal in deep time on earth. It is defined as laminated accumulation structure that is they stick up above sea floor . Stromatolite buildings includes oldest fossils which are 3.5 billions old when the earth were too unfriendly to support life.The study of  fossil age, evolutionary, method of formation are known as paleontology. These specimens are considered as old fossils which are around 3.4 to 4.1 billions years old.