The Erniettomorphs are a form of Ediacaran fossil consisting of rows of airbed-like tubes arranged along a midline with a glide symmetry, vaguely resembling plant leaves in shape.

[1] Undisputed Erniettomorphs were Ediacaran, but the species Erytholus, Rutgersella, and Protonympha, who have by some been included in this group but are by no means clear members, are found through to the Late Devonian.

Their affinity is uncertain; they probably form a clade and are most likely a sister group to the rangeomorphs, which bear a similar (though fractal) construction.

Placements within the metazoan crown-group have been rebutted, and it is most likely that these peculiar organisms lie in the stem group to the animals.

[2] Such a lifestyle requires a very high surface area to volume ratio – higher than is observed in fossils.