Kimberella quadrata

Overview

Kimberella quadrata is an Ediacaran organism described as having three connected body regions. A smooth outer band, a scalloped middle boundary, and a wrinkled inner region are known. The different surfaces within one body are intriguing.^[1]

Key facts

The surface changes in appearance from the outside inward. Beyond the smooth band are a scalloped boundary and inner wrinkles. The regions are studied as a single connected body.^[1]

Time and place

It was studied in an original paper on Ediacaran fossils. The Ediacaran was roughly 640–540 million years ago. Its unfamiliar body divisions raise questions about the construction of very ancient organisms.^[1][2]

The time range describes source context, not the complete duration of this species.

Size, form and skeleton

The description distinguishes three regions: outer, middle, and inner. The outer band is smooth, the middle boundary is scalloped, and the inside has wrinkles. One end is rounded, and a simple projection is interpreted at the opposite end.^[1]

The shield-like covering over Kimberella’s back was reported to reach about 15cm in length in large specimens. The broad foot underneath could extend beyond it, so the size of the covering should be distinguished from that of the whole body.^[10]

Habitat and reproduction

Did the three regions serve the same function? The researcher discussed the body’s construction based on its surfaces, boundaries, and the shapes of its ends. Research on such ancient organisms begins by asking which end was the front and which surface is exposed.^[1]

Fossil discovery

The original paper described projections and wrinkles in different specimens. Each specimen reveals different parts and adds information for comparison. The study examined the broad body outline alongside small surface features.^[1]

References

1. Original research — Three body regions of Kimberella
2. International Commission on Stratigraphy (2024) — Geological time chart
3. Original research — Three body regions of Kimberella
4. International Commission on Stratigraphy (2024) — Geological time chart
5. Evans et al. (2017) — Growth of Dickinsonia costata
6. Highly regulated growth and development of Dickinsonia costata
7. NASA — Feeding traces on the Ediacaran seafloor
8. Nilpena fossil site — Dickinsonia
9. South Australian Museum — Ancient fossil beds at Nilpena
10. Fedonkin et al. (2007) — The body and life of Kimberella

Research questions

How would interpreting the exposed fossil surface as the back or belly change our understanding of the body? Such questions of orientation are important in Kimberella research. They encourage us to begin with the connections among the preserved regions rather than first assuming a familiar animal body plan.^[1]

Observation

Move your gaze from the smooth outer band to the scalloped middle boundary and inner wrinkles. Looking separately at the rounded end and the projection at the other end reveals the different body regions.^[1]