Revelations in the Primal Fossil Record

"New actinopterygian fossils from the Tournaisian provide an opportunity to improve our understanding of earliest Carboniferous faunas and test whether other osteichthyan lineages follow the tetrapod pattern. Here, we describe a new genus of actinopterygian from a three-dimensionally preserved partial skull from Blue Beach, Nova Scotia, a locality in the Tournaisian Horton Group. This locality has previously yielded a diverse tetrapod fauna, as well as undescribed actinopterygian and sarcopterygian material [8,15,17]. Mirroring trends in the tetrapod fauna of this locality, this specimen demonstrates close affinity to taxa more typical of the Devonian, with clear implications for end-Devonian extinction survivorship among vertebrates."

A primitive actinopterygian braincase from the Tournaisian of Nova Scotia

Conrad D. Wilson, Jason D. Pardo, Jason S. Anderson

Published 16 May 2018.DOI: 10.1098/rsos.171727 

Avonichthys manskyi gen. et sp. nov. Photograph and interpretive drawing of specimen in dorsal view. Scale bar = 10 mm. br.psp, broken dorsal surface of parasphenoid; dsph, dermosphenotic; ?esc, indeterminate extrascapular; f, frontal; hm, hyomandibular; ifc, infraorbital canal; it, intertemporal; mx, maxilla; nIII, foramen for oculomotor nerve; p, parietal; por, post-orbital process; st, supratemporal.

"The old politics of the Devonian extinction is very much in debate. This is essentially a road map of new opportunities for young researchers who can work at this for many years...."

"The actual shape and patterns of evolution are not so clear."

"This highly dynamic environment [Bay of Fundy's Minas Basin], over four kilometres in length, creates unique opportunities for discoveries that would otherwise be very difficult to make."

"Nature does the digging here."

"These were findings and a paper generated from a single fossil, so we can only imagine how much more there is to be learned in the upstairs of Blue Beach Fossil Museum."
"There needs to be a new paleontology centre developed here to establish a permanent foothold for this fossil collection. It's a world-class collection and right now we have a private home-based, ma-and-pa museum. The collection has outgrown its home."

Chris Mansky, fossil researcher, curator, Blue Beach Fossil Museum

"There's nothing extraordinary about that moment [happening upon the fossil in question] at all. I was just literally walking along looking at the ground, kicking rocks, and I found one that was the shape of a bone. I didn't even know it was a fossil."

"It wasn't until a few months later that I actually put it under a microscope."

"... is it an artifact of preservation, the fact that we just don't have very many fossils of this age? Now that we're actually actively exploring, will we start filling in more of these lineages? Or is this one real lucky one that managed to squeak through [surviving mass extinction]?"

"We need to get a better idea of what other fish lived at that time, and in other places at the same time, and that will tell us more about how severely vertebrates were impacted by the mass extinction." 

Jason Anderson, vertebrate paleontologist, University of Calgary

Back in 2015 Dr. Anderson happened to be walking along a Nova Scotia beach. The area is known world-wide for the unique tides that wash the shoreline, the highest recorded in the world. As such, and as Dr. Mansky pointed out, those incessant tides and the force of the water scraping the shoreline has eroded it in a manner that reveals the presence of the fossils that appear to proliferate there. It is even possible that the fossil Dr. Anderson came across; the brain case of an ancient species of fish, might have washed ashore from another point in the area known as Blue Beach.

Out of the scientific record on ancient primal species and periods of development of the Earth and its creatures, the investigative team of Wilson, Pardo and Anderson zeroed in on the fish taxonomy recognizing its features and the fact that it was 350 million years ago that the creature lived, presumably in abundance. It is identified as an early Carboniferous fish, and the paleontological ichthyologists compared its features to other fish known to be related, on the same family tree.

 

Fish fossils found at Blue Beach, N.S., can help fill in evolutionary gaps between fish and four-legged creatures, such as this early tetropod which was fish-like, with tail fins, gills and up to eight fingers. (Richard Hammond)

Both Dr. Anderson's research and that of the scientists of the Blue Beach Fossil Museum appear to indicate that the lineage of which the discovered fish's skull is an example may be a survivor of an extinction that took place during the ancient Devonian period, indicating to the scientists that not all members of that branch of the group were entirely wiped out. The newly-discovered and identified species was named Avonichthys manskyi, named in honour of Dr. Mansky as well as the nearby Avon River. Dr. Mansky being honoured in view of years of avid collecting and exhibiting the Blue Beach-discovered fossils.

The findings of the team was published in the Royal Society Open Science journal, a British peer-reviewed scientific journal. Dr. Mansky emphasizes the uniqueness of the fish, that its discovery will lead researchers to begin observing and interpreting evolution in a different way. "It paves the way for future researchers. It gives us new theory and it upsets the old theory" [of evolutionary biology], he noted. Despite the investigation's conclusions in an exciting new find requiring an altered perception in judging the fossil record, there remain a multitude of questions to which there are no obvious answers.

Questions such as how many of the fish of this species or others like them of a different branch of the same species might possibly have managed to survive the mass extinction. Blue Beach is a generous fount of fossil discovery, given its constant erosion activity related to the high tides in the Minas Basin of the Bay of Fundy, reaming out the shoreline to reveal disturbed fossils, as examples of aquatic life forms vastly predating the appearance of homo sapiens in any of its proto-human forms.

 

Blue Beach, near Nova Scotia's Annapolis Valley, is the site of a discovery of fish species that lived 350 million years ago, casting new light on a little-understood time period. (Canadian Press)