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