Cephalopods from the Cambrian-Ordovician transition at Black Mountain (Queensland)

The oldest cephalopods in the late Cambrian are generally poorly studied, partly due to the scarcity of their fossils. In this project, I had the chance to investigate a previously undescribed fauna of cephalopods from the late Cambrian to earliest Ordovician of western Queensland, Australia. The specimens were already collected several decades ago by the late Mary Wade, and are unique in their abundance and three-dimensional preservation, allowing a detailed taxonomic description.

In the first paper on this fauna, we described Sinoeremoceras marywadeae and revised the taxonomy of the order Plectronoceratida, showing that due to their unique siphuncle morphology (Fig. 1), they were commonly misinterpreted. We found that the Plectronoceratida is identical with the proposed “Protactinoceratida” and vastly reduced the number of species (from 68 to 11).

Fig. 1. Reconstruction of the three-dimensional morphology of the siphuncle of Sinoeremoceras. From Pohle et al. (2024).

These are not the only cephalopods from this collection, so this is an ongoing project.

References

• Pohle, A., Jell, P. & Klug, C. (2024). Plectronoceratids (Cephalopoda) from the latest Cambrian at Black Mountain, Queensland, reveal complex three-dimensional siphuncle morphology, with major taxonomic implications. PeerJ, 12, e17003. https://doi.org/10.7717/peerj.17003