New fossil billfish species named in honour of Otago palaeontologist

Billfish are large predatory fish, such as marlins and swordfish, known for their long, spear-like upper jaws, which they use to catch prey. Photo / Supplied

A new species of fossil billfish has been named after a world-leading palaeontologist from the University of Otago.

A paper recently published in the journal Gondwana Research describes two large, rare fossil billfish skulls from the early Eocene period, about 50 million years ago, found in Otago, New Zealand.

Billfish are large predatory fish, such as marlins and swordfish, known for their long, spear-like upper jaws, which they use to catch prey.

Lead author of the paper, Dr Seabourne Rust, said the two skulls found represent early, now extinct forms of billfish.

“The more complete skull belongs to a new genus and species that we have named Zealandorhynchus fordycei, after the late Professor Fordyce,” he said.

Professor Ewan Fordyce was a vertebrate palaeontologist who had a 40-year career in the University of Otago’s department of geology before passing away in 2023.

The second fossil skull mentioned in the paper was discovered by co-author Morne Wium, and both species are now housed in the Earth Science New Zealand National Paleontological Collection.

Due to their large size, the pair are believed to have come from adult billfish, estimated to be several metres in length.

“These billfish specimens represent notable additions to a rather sparse Early Eocene fish macrofossil record from New Zealand,” Rust said.

“They hint at ancient diversity and widespread southern distribution reached by early billfishes during the Eocene – this is very significant as previously known distribution was considered to be nearly exclusive to the northern hemisphere.

“Ewan gave so much to his students; his well-illustrated lectures and legendary field trips brought the subject to life.

“He was a guiding mentor for me and many other budding palaeontologists. He has left such a legacy with his work on fossil vertebrates from Southern Zealandia, in particular.

“Many important discoveries were made during fieldwork in North Otago and Canterbury to recover ancient whales and dolphins, Ewan’s specialty, and subsequent long hours preparing the fossils unveiled insights into the creatures living in our area millions of years ago.

“My colleagues and I felt very privileged to honour Ewan’s memory by naming our new fossil billfish taxon after him.”