Taxa >> Kimberella quadrata

Updated: 10 Nov 2003

Kimberella quadrata

Abstract

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Keywords: yyy

Introduction

Kimberella quadrata was originally described from late Precambrian rocks of southern Australia. It is also found on the White Sea, in the Ust’ Pinega Formation, mostly in member 9, where is occurs across several facies, throughout the section. Here it is found associated with channels in a clay substrate, associated with Tribrachidium, Dickinsonia, meandering trace fossils, and small algae.

"Reconstructed as a jellyfish, it was later assigned to the cubozoans (‘box jellies’), and has been cited as a clear instance of an extant animal lineage present before the Cambrian. Until recently, Kimberella was known only from Australia, with the exception of some questionable north Indian specimens. We now have over thirty-five specimens of this fossil from the Winter Coast of the White Sea in northern Russia. Our study of the new material does not support a cnidarian affinity. We reconstruct Kimberella as a bilaterally symmetrical, benthic animal with a non-mineralized, univalved shell, resembling a mollusc in many respects. This is important evidence for the existence of large triploblastic metazoans in the Precambrian and indicates that the origin of the higher groups of protostomes lies well back in the Precambrian" (Fedonkin & Waggoner 1997, Abstract).

Morphology

Phylogeny and Evolution

Affinities

Fossil Record

Origins

Evolution

Extinction

Systematics

Phylum Echinodermata

Class unknown

Order unknown

Family unknown

Genus Kimberella Glaessner & Daily 1959 (verify)

Kimberella quadrata Glaessner & Daily 1959

Original Diagnosis: xxx

Description: Kimberella is oval to pear-shaped, bilaterally symmetrical, 3 to 105 mm long, possibly up to 140 mm (the range is continuous, with no apparent ontogenetic variation), possessing several features organised concentrically. The outer parts appear to have been relatively inflexible; the presumably softer interior, particularly the crenellated zone (fig. 1), is more commonly deformed.

Occurrence: xxx

Discussion: xxx

Fig. 1: Kimberella quadrata, from the Winter Coast of the White Sea, Russia. The adjacent parallel lines are trace fossils associated with Kimberella, and are believed to represent infilled feeding scratches through a microbial mat, suggesting that Kimberella possessed feeding structure similar to the molluscan radula [after Erwin & Davidson 2002, fig. 2].

Conclusion

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Further Information

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References

Erwin & Davidson 2002

Fedonkin & Waggoner 1997

Glaessner & Daily 1959

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