Fossils from Bacon Cove could rewrite history of squid, octopus
A set of fossils found in Bacon Cove, N.L. — and now housed permanently in the province's natural history collection — could rewrite the evolutionary history of deep-sea creatures like squid and octopus.
The tiny specimens, just a few millimetres in length, may well be the remains of the planet's oldest cephalopods.
"They roll back by about 30 million years the origins of cephalopods," said Nathalie Djan-Chékar, natural history collections manager at The Rooms, who gave CBC/Radio-Canada a first-hand look at the fossils in December.
"By law, any significant fossils have to end up here," Djan-Chékar said while holding one of the specimens, a razor-thin slice of limestone preserved on a microscope slide.
"The idea is that we keep these specimens in the province so people can see them and study them," she said of the thousands of fossils, but also taxidermied caribou heads and row upon row of bottled tentacles housed in the collection, an unmarked bunker on Merrymeeting Road in St. John's.
522 million years old
Last March, German researchers Anne Hildenbrand and Gregor Austermann of the University of Heidelberg announced in Communications Biology they had discovered the cone-shaped fossils at Bacon Cove, Conception Bay, in a layer of rock 522 million years old.
"If they should actually be cephalopods, we would have to backdate the origin of cephalopods into the early Cambrian period," said Hildenbrand, last March, when she and Austermann released their findings. "That would mean that cephalopods emerged at the very beginning of the evolution of multicellular organisms during the Cambrian explosion."
The Cambrian period lasted some 56 million years, ending with the beginning of the Ordovician Period about 485 million years ago.
Slicing the fossils into thin sections was necessary in order to identify them, said Djan-Chékar.
"In order to identify a mollusc as a cephalopod, they had to look at characteristics inside the organism. In paleontology, the way in which we do that is to make a very thin cut in the rock, which allows us to look inside," she said.
"Sometimes, the external structure is enough for identification, sometimes it's the internal structure that we really need to see."
More research is still needed to confirm the fossils are indeed the earliest known cephalopods in existence, according to the findings released in last March.
CBC/Radio-Canada attempted for months to speak with the two researchers behind the discovery, to no avail.