Reconstruction of the retiolitines

Retiolitids are one of the group of graptolites with collagenous skeleton (rhabdosome) formed mostly by a network of lists. In the paper the morphology of the skeleton of the Paraplectograptus was recognised thanks to 3D-preserved specimens (430 million years old) from the Arctic Canada and Poland and their detailed study uder SEM. The thecal fusellar wall was reconstructed despite its fragmentary preservation. Paraplectograptus is among the first retiolites showing some morphological features that afterwards were characteristic for all members of the group after the lundgreni Event. The presented models are by Nancy Kirk.