This story starts in the high latitudes of the Southern Ocean when the enigma lands on a pitching and windswept deck at the feet of Professor Joanne Whittaker and ends in the cosy study of Dr Erich Fitzgerald and the labs of Museums Victoria.
Professor Whittaker was at the time trying to learn the secrets of a chain of submerged extinct undersea volcanoes by dragging their cliffsides with a giant bucket on board the CSIRO’s flagship RV Investigator.
“The ship has a big metal ring about 40cm x 1m wide attached to a giant bucket. We target the side of an undersea mountain about 2-3km under the ocean (but still 3km above the seafloor) and drag the bucket along the mountainside - and hope.”
“The whole process takes six hours to lower the bucket and bring it back up – sometimes you are bitterly disappointed. It’s a bit of a lucky dip.”
Professor Jo Whittaker.
PHOTO CREDIT: UNIVERSITY OF TASMANIA/CSIRO
On this particular day the bucket’s contents included what scientists call “a biological”.
“We only expect rocks and that’s what we get – it’s highly unusual to find a biological.”
At first the university of Tasmania marine geophysicist thought it was ancient kelp. “I picked it up and it was incredibly dense, discoloured and beginning to fossilise. I thought: that’s not a rock.”
Whale ear bone.
PHOTO CREDIT: CSIRO
After her deck duty, she hits Investigator’s satellite wifi to do some serious Googling. Deciding to “get seriously CSI on its ass”, she emails Senior Curator of Vertebrate Palaeontology at Museums Victoria, and tells him to expect a package.
Back in port the sample is bubble wrapped and shipped to Dr Fitzgerald.
Dr Fitzgerald takes up our story: “I am a palaeontologist uncovering the evolution of whales and dolphins, so sorting out whale bones is my trade.
“When I receive a call to identify a mysterious whale bone from the Deep Sea or Deep Time, I answer that call.
“Within days of receiving the request to identify this find, I arrived at the museum to find a small unassuming cardboard box on my desk.”
Whale ear bone.
PHOTO CREDIT: CSIRO
Opening the box and cupping the ear bone in his hand he could immediately tell from its anatomical quirks that this was the tympanic bulla bone of a beaked whale of the family Ziphiidae.
“Then came the detective work of comparing the bone to others like it in the Museum Victoria’s collection as well as turning the pages of scholarly articles from the 1880s to today.
“At last it became clear that this bony messenger from the Deep is from a Cuvier's beaked whale, which has the formal scientific name Ziphius cavirostris.”
At first he didn't think he and his team would be able to identify this ear bone right down to species.
“But the team is fortunate in that they recovered one of the more distinctive beaked whale ear bones.
“The Cuvier's beaked whale is known to occur in the seas from which the ear bone was plucked, so the presence of this particular ear bone in that part of the world is not too surprising.
“Nevertheless, it is astonishing that we can identify exactly what whale species it was that left its ear bone on the seafloor from the anatomy of the ear bone alone.”
CSIRO RV Investigator.
PHOTO CREDIT: OWEN FOLEY
Professor Fitzgerald says the whole adventure of discovery is proof positive of the power of taxonomy and museum-based scientific expertise to help solve mysteries of nature.
“Whale bones on the seabed give us crucial clues to the past, present and perhaps future of what is going on out there in the places we humans fortunately don't yet have complete mastery over.”
Asked how old the find was, Dr Fitzgerald says: “It could be from a whale that died 2500 years ago, but less than 5000.”
Don't miss the Australian Museum's Whales | Tohora Exhibition - come face to face with the world's largest animals, the giants of the ocean.