#mesoproterozoic

[goodrichthyseskdalensis]

I wonder what it would be like if mesoproterozoic acritarchs had social media...

[goodrichthyseskdalensis]

Hearing people rave about the Ediacaran biota and how mysterious and ancient they are feels kinda odd to me now as someone who is now *VERY* aware of all the weird stuff that existed hundreds of millions to billions of years before that. Don't get me wrong, the Ediacaran biota are great, but there's just so much interesting stuff from before them that hardly gets covered, like the organisms pictured above (except for the bottom one, which is purely Ediacaran), which, speaking of which, I should probably explain.

The top two organisms pictured above are both members of the genus Horodyskia, the string of beads. The top one is the smaller Horodyskia minor, which, if my memory serves correct, has been found from the Ediacaran to the Tonian, sometime prior to 720 million years ago. The middle one is Horodyskia moniliformis, a larger species that I believe spans from the Tonian to at least the Calymmian, specifically sometime around 1480 million years ago (1.48 billion years ago). Both are rather small, with the beads of H. minor typically measuring around 0.1 to 0.8 mm and the beads of H. moniliformis typically measuring around 0.8 to 10 mm. They are reconstructed inside of a gelatinous halo based on well preserved specimens from the Ediacaran and Tonian.

Oh and Jiumenia is a weird thing from the late Ediacaran that also has a halo.

Here are some papers on the subject*:

Tonian carbonaceous compressions indicate that Horodyskia is one of the oldest multicellular and coenocytic macro-organisms - Communications

Carbonaceous compressions of Horodyskia from the Tonian successions reinforce the biogenicity of these macrofossils and indicate that they a

Restudy of string fossils from the Ediacaran-Cambrian Liuchapo Formation in Guizhou Province, South China

String fossils, Horodyskia and Palaeopascichnus are globally distributed in Proterozoic strata. They are composed of uniform segments with s

*unfortunately, the second one requires you to log in via an organisation.

[katborg82]

The Mesoproterozoic era began 1.6 billion years ago and lasted to 1 billion years ago. What little life survived the oxygen catastrophe would continue to diversify and evolve in ways life had not yet seen. The emergence of eukaryotes would pave the way for life as we know it today. They would adapt new ways to survive like decomposition, predation, even sexual reproduction.

From 1.8 to 0.8 billion years ago, is a time period known as "The Boring Billion", named for the relative stability in tectonic activity and the climate, as well as seemingly slow moving evolution, but life will be picking up the pace exponentially in the next few hundred million years.

[geologyjohnson]

#mesoproterozoic #microbial sediments from Northern Territory, Australia, ~1.3 billion years old! #geology #palaeontology #stromatolite (at Oxford University Earth Sciences) https://www.instagram.com/p/B1WOaCiJ56T/?igshid=14vvqr4c8kliz

[geologyjohnson]

"The precious" 1.4 billion year old #sulphide nodule. Contains #pyrite #chalcopyrite #galena #sphalerite and maybe #calcite looks to be a replacement texture and maybe hydrothermal in origin. #sedimentology #Precambrian #mesoproterozoic

[geologyjohnson]

"High risk colouring in" mapping the #mesoproterozoic of the northern territories #Australia #geology #precambrian

[oberlinsciencelibrary]

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[geologyjohnson]

SEM image taken by me of a 1.5 billion year old black shale sample from Northern Australia. More to come soon with a proper write up. :)