Eastern Cape home to earliest known coelacanth fossil

More than 30 specimens of a new fossil species of coelacanth have been found near Grahamstown in the Eastern Cape, according to the University of the Witwatersrand.

An article describing the new species was published in the Zoological Journal of the Linnean Society of London on Monday.

Here are five interesting facts about the discovery:

1) This is a new species of Coelacanth

The specimens of Serenichthys kowiensis were collected by palaeontologist Dr Robert Gess from a 360 million year-old fossil estuary.

It was described by him, together with Professor Michael Coates from the University of Chicago.

Gess did the research while completing his PhD at the Evolutionary Studies Institute at the university.

2) The fossils indicate that the Serenichthys kowiensis specimens were ‘juveniles’

“Remarkably, all of the delicate whole fish impressions represent juveniles. This suggests that Serenichthys was using a shallow, waterweed-filled embayment of the estuary as a nursery, as many fish do today,” Gess said.

“This earliest known record of a coelacanth nursery foreshadows a much younger counterpart, known from the 300 million year old Mazon Creek beds of Illinois in the United States.

“This glimpse into the early life history of ancient coelacanths raises further questions about the life history of the modern coelacanth, Latimeria, which is known to bear live young, but whether they, too, are clustered in nurseries remains unknown.”

3) The fossils came from black shales originally disturbed by roadworks at the nearby Waterloo Farm.

Gess originally identified coelacanth remains from the locality whilst carrying out excavations at Waterloo Farm in the mid-1990s under the supervision of Dr Norton Hiller, from the Rhodes University Geology Department.

Those fossils were not preserved enough to be reconstructed and described.

Gess’s excavation of the shale salvaged during the more recent roadworks led to discovery of the new specimens, which were preserved in detail.

4) This new species was discovered near the spot where a modern coelacanth was found in 1938. Until that date the coelacanth was thought to have become extinct over 65 million years ago.

The new species was discovered 100km from the mouth of the Chalumna River, off which the Latimeria chalumnae – the first discovered modern coelacanth – was caught in 1938.

In keeping with the naming of its living relative, the species name of the new fossil form, kowiensis, is after the Kowie River and the genus name, Serenichthys, honours Serena Gess, who provided land for the storage of more than 70 tons of black shale rescued from the roadworks.

5) Coelacanths are believed to have arisen during the Devonian Period – about 419 million years ago

Only five species of reconstructable Devonian coelacanths had previously been described. This was in addition to a number of fragmentary remains. None of these came from Africa, but rather from North America, Europe, China and Australia.

The new species gives important additional information on the early evolution of coelacanths.

“According to our evolutionary analysis… it is the Devonian species that most closely resembles the line leading to modern coelacanths,” Gess said.

Ahmed Areff, News24