Rare Isoxys Death Assemblage from Chengjiang

Isoxys auritus

Phylum Arthropoda

Geologic Time: Early Cambrian (~525 million years ago)

Size (25.4mm=1 inch): 24-31 mm long by 7- 11 mm tall on a 60 mm by 68 mm matrix

Fossil Site: Chengjiang Maotianshan Shales, Quiongzhusi Section, Yu’anshan Member, Heilinpu Formation, Mafang Village, Anning, Kunming, Yunnan Province, China

Isoxys auritusDescription: This unusual arthropod is known as Isoxys auritus. The species is known mostly from the distinctively–pointed bivalved carapace. 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. Isoxys

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. With FOUR nearly perfect shells, this is the ONLY multiple example I have yet been able to secure

click to enlarge

l Paleontology & Fossils l Paleobiology and Geologic Timeline l
l Fossil Amber l Ammonite Fossils l Dinosaur and Reptile Fossils l Fossil Kits l
l Crinoids and Echinoderms l Fish Fossils l Fossil Dealers l Insect Fossils l Invertebrate Fossils l
l Plant Fossils l Stromatolites l Trace & Ichnofossils l Trilobite Fossils l Vertebrate Fossils l