Isoxys auritus Chengjiang Arthropod with Preserved Eye

Description: This unusual arthropod is known as Isoxys auritus. The species is known mostly from the distinctively–pointed bivalved carapace, but this specimen has the eye preserved in great detail, the FIRST such example I have been able to obtain.

The diversity of soft-tissue fossils from Chengjiang 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 taxon is only rarely preserved with any soft parts evident. Based upon the few known examples, it had a long segmented body, forwardly-projecting stalked eyes, and short antennae. The swimming appendages and most other soft parts only protruded slightly from their protective shell. This taxon is known only from the Chengjiang Biota, but other members of the genus are found in deposits in Europe, Australia, and North America. It is likely that a bit more is preserved at the posterior and lower edge of the shell, still obscured by matrix.