''Temnoxa molluscula (Temnoxa molliuscula)'' is a small creature approximately 8 mm wide found in the

Ediacaran period The Ediacaran Period ( ) is a geological period that spans 96 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 538.8 Mya. It marks the end of the Proterozoic Eon, and th ...

(558-555 Ma) in Russia. The ''Temnoxa'' has a resemblance to a vertically cut penny bun mushroom. Due to the lack of information regarding the fossils of this organism, researchers are unable to place ''Temnoxa molluscula'' into any known phylum. The genus was originally discovered by Russian paleontologist Andrey Yu. Ivantsov in 2004. Due to its body lacking

metameric In biology, metamerism is the phenomenon of having a linear series of body segments fundamentally similar in structure, though not all such structures are entirely alike in any single life form because some of them perform special functions. In ...

(linear series of body segments) appendages, it's highly hypothesized that this creature was closest related to mollusks. However, there are opposing theories regarding the accuracy of this categorization because its unsegmented body and U-shaped head is far too large to be considered a mollusk. It also lacks a single shield-like mantle, although a mantle-like structure appeared to slip away from a dorsal side of the body in the holotype. ''Temnoxa molluscula'' also appeared to lack a respiratory and sensory processes. This creature may have had a crawling foot. Its bilateral symmetry suggests motility in ''Temnoxa''. Another reason scientists hypothesize mobility for this organism is because in 2017, researchers from around the world observed the way that water flowed around its shell. It was discovered that they were able to face the direction of the water current using their U-shaped heads, and are most likely the oldest known species to have this capability. They may have been able to attach themselves to substrate using their sticky foot. This organism is compact yet flexible, able to enclose a visceral mass. Nevertheless, no direct fossil evidence exists for internal organs (Ivanstov et al. 2012). ''Temnoxa'' shares certain features with other Ediacaran creatures, ''

Kimberella ''Kimberella'' is an extinct genus of bilaterian known only from rocks of the Ediacaran period. The slug-like organism fed by scratching the microbial surface on which it dwelt in a manner similar to the gastropods, although its affinity with t ...

'' and ''

Parvancorina ''Parvancorina'' is a genus of shield-shaped bilaterally symmetrical fossil animal that lived in the late Ediacaran seafloor. It has some superficial similarities with the Cambrian trilobite-like arthropods. Etymology The generic name is derived ...

''.

References

{{Taxonbar, from=Q85805526 Enigmatic prehistoric animal genera Ediacaran life White Sea fossils Fossil taxa described in 2004

See also

References