A new gyracanthid (stem Chondrichthyes) from the Late Devonian (Famennian) of the Eastern Cape, South Africa

ABSTRACT

A new gyracanthid Gyracanthides riniensis is described from the Famennian (latest Devonian) Waterloo Farm Lagerstätte in the Witpoort Formation, near Makhanda/Grahamstown, South Africa. The new species is based on disarticulated remains including pectoral, pelvic, and median fin spines, endoskeletal shoulder girdle elements, and squamation patches preserved on or close to the same bedding plane. The new taxon is distinguished by having a relatively large, ornate median spine, and arrowhead-shaped tubercular ornament on the spine ridges. The species shows closest resemblance in pectoral spine proportions to Gyracanthides murrayi from the earliest Carboniferous of Australia, and in spine tubercular ornament to its Laurussian contemporary “Gyracanthus” sherwoodi. It differs in spine proportions and ornament from the older (Givetian) and younger (early Carboniferous) gyracanthids found in nearby localities.

http://zoobank.org/urn:lsid:zoobank.org:pub:ADF4869C-45DC-4854-9F27-37D490F6D388

ACKNOWLEDGMENTS

We thank C. Reddy and R. Nel (DEP) for preparing and whitening casts. John Almond is thanked for loan of the cast of the specimen examined by Chaloner. Insightful comments by Reviewers and the Editor were very helpful in revising the manuscript. RG is funded by the Millennium Trust, GENUS (DSI-NRF Centre of Excellence in Palaeosciences) and the NRF of South Africa.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the author(s).

AUTHOR CONTRIBUTIONS

Both authors designed the project and drafted the manuscript.