Blue Shark


Taken from the Times Globe, Monday, June 21/99

Scientist find shark-infested waters
Rare Discovery: The oldest complete shark fossil in the world, found near Atholville 3 years ago, finds its way to world experts on early fossil fish

Curator, Randy Miller
Randy Miller, a curator at the New Brunswick Museum,
holds part of the oldest fossilized complete shark skeleton in the world.

By Erin Dwyer
Times Globe staff writer

    New Brunswick Museum geologist Randy Miller knew from the moment he examined the fossil closely that he had a rare find.
    The piece of rock that a student discovered on this expedition didn't just contain another fossilized shark's tooth. Many samples of these and other fish remains had been found in the Devonian rocks near Atholville ,since the late 1800s.
    Looking at the area where it came from, Dr. Miller, curator of geology at the Saint John-based museum, realized that he and his team had found something special. He later learned it would be the oldest complete shark fossil in the world.
    Last week the find - made nearly three years ago - was presented to world experts on early fossil fish gathered in Flagstaff, Arizona by two of Dr. Miller's colleagues.
    Scientists from around the world got a chance to see the 395-million year-old fossil, which represents about one-third of the body of the shark. Earlier fossilized scales and denticles belonging to sharks have 'been found, but until now the oldest ,relatively complete shark that has been described is a 382-million-year old specimen found in Antarctica.
    "We came across the specimen which is unusual in that sharks usually fall apart when they fossilize, the teeth .and the scales and things disarticulate and they get scattered through the sediment and that's usually what you ,find," Dr. Miller said yesterday in an interview.
    "So the earliest sharks are only represented by scales and this specimen is relatively complete for a shark fossil. "
    It was July, 1997, and Dr. Miller, two students and his six-year-old son were in the Atholville area to re-examine sites where significant fossil 'finds had been made more than a hundred years ago. Dr. Miller was hoping the expedition would boost the museum's collection since most of the specimens collected there earlier in the century had been donated to the Scottish Museum in Scotland and the British Museum in London.
    The team had split up. Dr. Miller and his son were poking through rocks in one area when summer student Jeff McGovern came across something unusual.
    "He came strolling over with a big grin on his face and said, 'We haven't seen one of these before' and I guess he wasn't exactly sure what it was," Dr. Miller said.
    "Then we puzzled over it for a minute and looked at it and it was the part of the jaw, and I took out the magnifying glass and I could see the teeth in the jaw. We had already found the teeth so we knew that there were sharks there; we knew what we were looking for but they are so rare that we didn't expect to find one.
    "I went over and looked at it, and sure enough you could see the gill slits lined up in the little v-shaped patterns in the sediment. So we spent the next few hours excavating this. It was pretty neat actually. We didn't expect to see one that was held together like this because we knew that they are pretty rare. "
    The shark would have measured about half a metre long and likely lived in a low-saline estuary or lagoon. Looking at the fossil, you can see teeth still intact in the jaw, gill slits and the scales that made up the texture of the shark's skin.
    The fossil, which is about 10- to 15-million years older than the Antarctica specimen, provides another piece of the puzzle in the evolution of the shark.
    "Anything we learn pushes things back a little further," he said.
    Dr. Miller said this fossil does shed new light on the evolution of the shark. It indicates the shark had spines along its pectoral fins - fins located on either side of the shark and used to steer.
    "This may well be the first occurrence of a paired spine," he said.
    "Little details like this by themselves don't sound like much but they are all sort of little details about what did sharks evolve from and what did they have in their early stages. What sort of features did they have?"
    Scientists will also be able to look at its association with other fish and scorpions from the Devonian period.
    "Sometimes you find specimens in museum drawers that you don't know what they were collected with," he said. "In this case, we collected it and so we know exactly where it was. "
    In fact, it was found about a metre away from the fossilized skeleton of a big sea scorpion, which would have looked similar to a two-metre long lobster.
    Dr. Miller has a preliminary theory on the close proximity of the two fossils, one that will require more study. He said the scorpions could have travelled to the lagoon or back water to molt - shed their skin - much like lobsters do today.
    "It may be a time when they are fairly vulnerable," he said. "It could be that the sharks were there because it was feeding time.