Stromatolites are
A) fossils of the first organisms to introduce oxygen into the atmosphere
B) fossils of the first multicellular organisms
C) layers of sediment that once contained colonies of ancient microbes
D) fossils of the first eukaryotes

Question

Quizplus · Accepted Answer

Stromatolites are layers of sediment that once contained colonies of ancient microbes. They are formed by the trapping and binding of sediment particles by the sticky mucilage produced by microbial communities, which results in the accumulation of layers over time. They represent some of the earliest evidence of life on Earth, but they are not fossils of the first organisms to introduce oxygen into the atmosphere or the first multicellular organisms. Stromatolites are also not fossils of the first eukaryotes, as they are formed by prokaryotic microbes.

Stromatolites Are