9 A fast-swimming ancient mackerel-like fish from Abbotsford

Osteichthyes, Scombriformes: Scombrinus dunedinensis

In the early 1930s Professor William Noel Benson took a small collection of fossil material to a fossil fish expert Frederick Chapman in Australia (read more about this here: Dawn barracouta from Dunedin studied across time). One of the specimens that Professor Benson had with him was a crushed but still impressive partial skull with a row of ferocious teeth. The skull measures about 18 cm tall, 17 cm long and around 12 cm wide. The fossil preserves 16 teeth but a full set would have comprised 36 teeth. The fossil is embedded in a marly greensand matrix. Chapman would eventually describe this skull as a new species of ancient mackerel-type fish.

Professor Benson had borrowed the skull from the ‘Marshall collection’, a subset of fossils within the University of Otago Geology Museum that had been curated by Professor Patrick Marshall. From 1901 to 1906 Marshall was a lecturer, and then professor, in the Otago School of Mines, the predecessor to the Department of Geology.

When Chapman described the fossil skull he used the name “Portheus”, which is no longer used. Instead the specimen is now named Scombrinus dunedinensis while it awaits new and more detailed study.  Scombrinus is an extinct genus of mackerel-like bony fish that lived during the Eocene. The specimen is unlike any other fossil or living fish known from Aotearoa New Zealand and most closely resembles mackerel-like fish collected from the Eocene London Clay, on the other side of the world from Ōtepoti Dunedin.

—Written by Daphne E Lee and Jeffrey H Robinson