Stunning Detailed Eoredlichia intermedia Trilobite from Chengjiang
"fossils of the Cambrian Explosion"

Eoredlichia intermedia

Trilobites Order Redlichiida, Family Redlichiidae

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

Size: Trilobite is 20 mm long and 17 mm across on a 41 mm by 41 mm matrix

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

Description: This trilobite is a member of the Order Redlichiida, Family Redlichiidae from the Early Cambrian Heilinpu Formation deposits near Anning, in Kunming County, Yunnan Province, China, known as Eoredlichia intermedia. The species is one found in several locations within Yunnan Province in what is termed the Chegjiang Biota by Hou Xian-guang in 1984. 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 Redlichioids of this type are considered to be the sister-group comprising all of the “higher” (non-Olenelloid) trilobites by Richard Fortey. Eoredlichia is thought to have lived on or close to the seafloor. Based upon its spinose limb bases and braced hypostome, it is thought by some researchers to have led a predatory existence. Missing only the axial spine, this is a highly desirable specimen due to its association with the Chengjiang Biota that made up a glimpse of the Cambrian Explosion some 5-10 million years before the Burgess Shale fauna came into being. Notice the sweeping spines that have been preserved. I have included an artist’s (my daughter’s) rendition of its appearance in life.

click fossil pictures to enlarge

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