The
Vernanimalcula fossils were interpreted as showing a
triploblastic structure, a
coelom, a differentiated
gut, a mouth, an
anus, and paired external pits that were believed possible
sense organs, making it the earliest known member of the
Bilateria (
animals with
bilateral symmetry, at least as embryos). The appearance of
Vernanimalcula so early in the fossil record was believed to have had important implications if it were really bilaterian. The radiation of animals into many
phyla would have occurred before any animal became much larger than microscopic size, making the sudden appearance of many animal phyla in the
Cambrian explosion an illusion and merely represented a (geologically) sudden increase in size and the development of easily fossilised body parts by
species in existing phyla. The description of
Vernanimalcula as bilaterian has been strongly challenged. Other workers (Bengtson,
Budd and co-workers) in the field have repeatedly claimed that
Vernanimalcula is largely a
taphonomic artefact generated by phosphate growth within a spherical object such as an acritarch, and thus
Vernanimalcula was not even an
animal, let alone a bilaterian. Chen
et al. initially defended their interpretation of
Vernanimalcula against the claims of Bengtson and Budd. Petryshyn
et al. examined additional fossils resembling
Vernanimalcula and concluded that the fossils are "likely biogenic in nature." == See also ==