Enduring evolutionary embellishment of cloudinids

The Ediacaran–Cambrian transition and the following Cambrian Explosion are
among the most fundamental events in the evolutionary history of animals.
Understanding these events is enhanced when phylogenetic linkages can be
established among animal fossils across this interval and their trait
evolution monitored. Doing this is challenging because the fossil record
of animal lineages that span this transition is sparse, preserved
morphologies generally simple, and lifestyles in the Ediacaran and
Cambrian quite different. Here we identify derived characters linking some
members of an enigmatic animal group, the cloudinids, which first appeared
in the late Ediacaran, to animals with cnidarian-affinity from the
Cambrian Series 2 and the Miaolingian. Accordingly, we present the first
case of an animal lineage represented in the Ediacaran that endured and
diversified successfully throughout the Cambrian Explosion by embellishing
its overall robustness and structural complexity. Among other features,
dichotomous branching, present in some early cloudinids, compares closely
with a cnidarian asexual reproduction mode. Tracking this morphological
change from late Ediacaran to the Miaolingian provides a unique glimpse
into how a primeval animal group responded to the Cambrian Explosion.