Leanchoilia Opabinid Arthropod from Chengjiang

Leanchoilia illecebrosa (Chengjiang)

Phylum Arthropoda

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

Size (25.4mm=1 inch): 40 mm long (with antennae) on a 50 mm by 33 mm matrix

Fossil Site: Chengjiang Maotianshan Shales, Quiongzhusi Section, Yu’anshan Member, Heilinpu Formation Yuxi, Chengjiang County, Yunnan Province, China

Leanchoilia illecebrosaDescription: This unusual arthropod is known as Leanchoilia. The taxon is known from a number of locations within the Chengjiang region. 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.

This specimen is a member of the “great appendage arthropods” known as the Leanchoilia after Opabinia from the Burgess Shale Fauna. Other members from Chengjiang are Jianfengia and Alalcomenaeus (see my other offerings for examples). The exceptional detail of the appendages is readily apparent in this fine specimen, and is indicative of the fact that this was a strong swimmer. This is a truly exceptional specimen, showing a portion of the flagellate antennae believed to have performed a sensory function, and as such is quite uncommon. The artistic picture of the taxon shows what they likely looked like in life.

Also see: Chengjiang Biota List Chengjiang Fossils

click to enlarge

l Fossil Mall Home l Fossils Science Section l