Animation: Stromatolite Formation

The oldest stromatolites have been dated to _______ years ago.

3.5 billion

Ancient (3 million year old) fossil stromatolites are found on wind-swept alpine ridges at an elevation of 1,800+ meters (6,000+ feet) of elevation in the mountains of Wyoming in the Rocky Mountain Range of the United States. What would be the most likely interpretation to explain this distribution?

Geological uplift elevated previously shallow marine sediments to high altitudes.

There are structures in modern-day Western Australian near-shore habitats that are thought to be living modern equivalents of stromatolite fossils. Which of the following hypothetical observations would disprove this hypothesis?

It is determined that the cells comprising the biological component of the layers have nuclei.

Cyanobacteria

photosynthetic bacteria that are single-celled but often form colonies in the form of filaments, sheets, or spheres and are found in diverse environments (such as salt and fresh water, soils, and on rocks)

Stromatolites are a type of fossil that is made from:

the growth of cyanobacteria and other heterotrophic bacteria entrapped in calcium carbonate and other mineral sediments.