Valeria lophostriata

Overview

Valeria lophostriata is a microfossil with concentric striations preserved on its wall. Follow the lines on a small wall fragment to explore the very ancient world of the Mesoproterozoic.^[1]

Key facts

Fossils do not preserve only fully opened forms. Examining partly rolled walls alongside walls still splitting reveals different states of preservation under the same name.^[1]

Time and place

It appears in research on the early Mesoproterozoic Roper Group. The locality is in present-day Northern Territory, Australia. The study examined minute traces of life preserved in thick sedimentary rocks there.^[1]

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

Size, form and skeleton

The vesicle wall characteristically bears striations that appear to encircle a center. Specimens beginning to split through the middle were presented alongside ones whose walls had partly rolled after splitting.^[1]

The sac-like fossils presented in a 2022 study are approximately 60–250 µm in diameter. Converted to millimeters, these small fossils measure about 0.06–0.25 mm.^[4]

Habitat and reproduction

The Roper assemblage studied was most diverse in nearshore settings. Microfossils interpreted as eukaryotes were also abundant in shales of the nearshore continental shelf.^[1]

Fossil discovery

The researchers recorded slide numbers together with coordinates so that the same microfossils could be located again. Several slides of U6 material preserve different states of Valeria.^[1]

References

1. Javaux·Knoll — Early microscopic life of Australia’s Roper Group
2. Loron (2016) — Organic-walled microfossils from the Tonian of Sweden
3. Javaux·Knoll — Early microscopic life of Australia’s Roper Group
4. A case for an active eukaryotic marine biosphere during the Proterozoic era

Research questions

Javaux and Knoll’s 2017 study compared 34 taxa in the Roper assemblage. By combining the forms and environments of small fossils, it explored the diversity of early eukaryotes.^[1]

Observation

In the illustration, examine the curve of the partly rolled wall and then the concentric striations on its surface. Moving your gaze from the open surface to the curled edge reveals differences across a small surface.^[1]