Very fine particles of solids i . e . sand, crushed shell etc . are trapped by the sticky bacteria, to become cemented with calcium carbonate produced by the bacteria, thereby building up the stromatolite structures.
32.
According to these specimens, species of " Holonema " lived by grazing on stony, horn-shaped, stromatolite-like algae called oncholite, apparently by snipping off the points with a specialized snout.
33.
In the late Archean Eon an oxygen-containing atmosphere began to develop, apparently produced by photosynthesizing cyanobacteria ( see Great Oxygenation Event ), which have been found as stromatolite fossils from 2.7 billion years ago.
34.
There are three basic types of Stromatolite, the sub-tidal ( always under water ) columns and the inter-tidal ( exposed to air and sun during low tides ) anvil or mushroom shapes depicted in most pictures.
35.
In the journal article, the scientists said this strictly nonbiological dynamical model of stromatolite surface growth " calls into question the assumption that organisms _ even if present _ necessarily played an essential role in determining stromatolite morphology ."
36.
In the journal article, the scientists said this strictly nonbiological dynamical model of stromatolite surface growth " calls into question the assumption that organisms _ even if present _ necessarily played an essential role in determining stromatolite morphology ."
37.
Applying the principles of fractal geometry, they could begin to deduce the processes of stromatolite growth, which involved calcium carbonate suspended in water falling to the sea or lake floor, some downslope movement and rearrangement of sediments and other factors.
38.
During the beginning of the Tonian period around 1 billion years ago, there was a decrease in Stromatolite diversity, which may indicate the appearance of grazing animals, since stromatolite diversity increased when grazing animals became extinct at the End Ordovician extinction events, and decreased shortly after the grazer populations recovered.
39.
During the beginning of the Tonian period around 1 billion years ago, there was a decrease in Stromatolite diversity, which may indicate the appearance of grazing animals, since stromatolite diversity increased when grazing animals became extinct at the End Ordovician extinction events, and decreased shortly after the grazer populations recovered.
40.
There are various different micro-organisms that can create them ( generally, the fossil record only preserves the stromatolite, not the bacteria that created it, so it's hard to tell precisely what made them ), but I not sure whether any of them are in our line of descendants.
