Fine Fuxianhuia protensa, an Unusual Arthropod from Chengjiang

Description: This unusual arthropod is known as Fuxianhuia protensa. The species is known from several hundred examples, with this one being a large example. The diversity of soft-tissue fossils is astonishing: algae, medusiforms, sponges, priapulids, annelid-like worms, echinoderms, arthropods (including trilobites), hemichordates, chordates, and the first agnathan fish make up just a small fraction of the total. Numerous problematic forms are known as well, some of which may have represented failed attempts at diversity that did not persist to the present day.

The systematic position of this taxon is still under debate, with some considering it a basal euarthropod. The discoverer of the Chengjiang Biota and a coworker erected a new family and a new superclass called Proschizoramia which was characterized as a group at any early stage in the evolution of arthropods with biramous limbs. The taxon is unknown outside the Chengjiang Biota.