Giant Prehistoric Fish From Ancient Supercontinent Found Under Road
A giant prehistoric fish from an ancient supercontinent has been discovered underneath a rural road in South Africa.
The fossil was excavated from a roadside near Waterloo Farm in the south of Makhanda. Findings from the discovery have been published in a study in the journal Plos One.
The study revealed the fossil is from the tristichopterid family—an extinct group of huge, lobe-finned fish that lived during the Devonian period, 419 million years ago. Scientists found the majority of the dermal skull, lower jaw, gill cover and shoulder girdle during the excavation. The new species has been named Hyneria udlezinye.
This particular fish would have been at least 8 feet long, the study said. This was the average size for these fish.
Rob Gess, paleontologist and research associate of South Africa's Albany Museum and co-author of the study, told Newsweek: "This is an entirely new species, as yet only known from the Waterloo Farm site. Although the related Hyneria lindae from Pennsylvania has previously been characterized by description of isolated bones and associations of bones, this is the first time that a reconstruction of the skull and shoulder girdle of a Hyneria has been achieved."
The tristichopterid family were the fish species most closely related to tetrapods—animals with four limbs. They are often used as examples of the pre-tetrapod ancestral form.
It is believed that these giant Tristichopterids evolved in Gondwana—a large landmass that formed 550 million years ago, often referred to as a supercontinent. Scientists think the species then migrated to Euramerica—another ancient continent.
This was because all but one genus of giant Tristichopterid was formally known from Gondwana, including some that are also found in Euramerica.
"Until recently there was one mysterious exception, Hyneria lindae, from North America. The discovery of a closely related species Hyneria udlezinye from southern Gondwana strongly supports the idea that these giants all originated in Gondwana. It represents an important missing piece of the puzzle," Gess said.
This newly identified species, Hyneria udlezinye, is thought to be the only Tristichopterid from the polar regions.
Most other known Gondwanan Tristichopterids come from modern-day Australia, which was on the tropical northern coast of Gondwana and has a far better-understood fossil record, Gess said.
The study said that the Hyneria udlezinye was likely to have been the top freshwater predator in the Waterloo Farm area.
"The tetrapod remains from Waterloo Farm are generally found associated on the same slabs as Hyneria remains. Undoubtably the Hynerias would have been the chief predators of the tetrapods," Gess said. "The tetrapods were adapted to hunting in shallow water, which was out of reach to the deep bodied Hyneria, however when they crossed stretches of open water they would have been easy prey for the lie-in-wait predatory Tristichopterids."
The Waterloo Farm excavation site provides the best record of the late Devonian ecosystem in southern Africa.
"In 1985 the black shale was first revealed in a roadcutting when a new bypass was constructed south of Makhanda. Excavations in the mid-1990s revealed a rich fossil record, however by the late nineties the cutting became unstable and had to be cut back," Gess said.
"Some of the Hyneria material was recovered at that time but most of the specimens were discovered subsequently during careful excavation of the rescued blocks, over many years. In many cases several examples of each bone have been collected. Careful analyses of these bones and scatters of associated bones has allowed reconstruction of almost the entire skull and shoulder girdle of this enormous fish."
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