Global evolutionary relationships of Devonian proetide trilobites

The Proetida likely represent the only trilobite surviving clade past the
Devonian mass extinction event(s). Though members of order Proetida have
long been studied, the global phylogenetic relationships across this
pivotal time are still unresolved. I used a Bayesian phylogenetic approach
to construct a subordinal level tree for members within superfamily
Proetoidea. Two models, a relaxed and strict clock model, were compared
and were used to assess past reconstructions of clades within the order.
The trees from both models highlight key relationships among proetides
across the Devonian and show paraphyly in groups which have been
considered monophyletic in the past. Trees from both models also suggest
that major groups, such as the genus Gerastos and the family Phillispidae
(which represent the most diverse post-Devonian proetide group under
current taxonomic schemes) are polyphyletic. This in turn suggests, in a
paleobiological context, a more complex pattern of survivorship over the
Late Devonian than previously suggested as well as pervasive parallelisms
towards certain "Gerastos" or “phillipsid”
morphotypes.