Habitable marine environments for the first forms of complex life may have been more extensive than thought during the Marinoan glaciationbetween 654 and 635 million years ago, according to an article published in the journal Nature Communications.
The findings suggest that habitable conditions in the open sea could have persisted even into the mid-latitudes during “Snowball Earth,” when the continents and part of Earth’s oceans would have been covered by a thick layer of ice.
According to the researchers, this time of freezing would have been more like a “ball of earth” hail”, so that some organisms were able to survive in certain places.
Some complex organisms may have lived in ocean shelters during the global ice age
About how complex life was able to survive during the ice age Marinoan Snowball Earth It has been a hotly debated topic. It is believed that oceanic refuges existed that allowed marine organisms to survive during this event. However, the environmental conditions that allowed this survival are still not well known.
The team led by Huyue Songfrom the Wuhan University of Geosciences (China), analyzed the geochemical composition of fossil-rich sediments from the Nantuo Formation, in southern China, dated from 654 to 635 million years ago, towards the end of the Cryogenic period. Scientists found fossils resembling photosynthesizing algae They lived on the seabed.
The investigation found possible fossils of algae that would have survived in the Nantuo Formation, China
Furthermore, the presence of hierro He told them that the deep waters were poorly oxygenated, but the aerobic process of nitrogen was probably taking place in the oxygenated surface waters. During the last ice age of Snowball Earth, these sediments were deposited from 30 to 40 degrees northmuch further north than would be expected in an unfrozen ocean.
The authors suggest that these mid-latitude oceanic reservoirs they served as refuge to complex organisms that survived periods of near-global freezing, allowing life to persist until conditions became more favourable.
Reference:
Song H. et al. “Mid-latitudinal habitable environment for marine eukaryotes during the waning stage of the Marinoan snowball glaciation”. Nature Communications (2023)
Fuente: SINC
Rights: Creative Commons.