Fedomia

When described, Fedomia was noted to bear similarities to the Cambrian genus Eiffelia from the Burgess Shale, as well as the similarly aged Vaveliksia, and was thus interpreted to be a sponge-grade organism with organic spicules.^[1] Although, the researchers did make note that during the description, some called for caution in this placement, due to their being no preserved three-dimensional form known, no wall deformation in any fossil specimens, and the variable size of the star-shaped structures, which are possibly a result of cavities within Fedomia being in-filled during burial.^[1] A later study by some of the same researchers would note that a sponge affinity cannot be ignored, it is hard to place it into any Phanerozoic taxa, reiterating the previously mentioned points, although comparisons can still be made.^[2]

Although, come 2014, Antcliffe et al. would publish a study that re-analysed all named sponge-like organisms from the Ediacaran at the time, which included Fedomia. The researchers noted that the original description did not provide any arguments for the sponge affinity, and also the difficulty of discerning any sponge-like features in Fedomia. Tihs would lead them to mention that Fedomia does not pass their criteria for being a sponge-like organism due to these reasons, but instead is more likely to be a microbial colony, or a macro-algal sheath.^[3] A few years later in 2017, a study published would make a quick mention of Fedomia being reported as spiculate, although not to a convincing amount, and making note of the previously mentioned criteria set out by Antcliffe et al. the previous year.^[4]

• List of Ediacaran genera