Study Pits Man v Machine in Piecing Together 425-Million Years Old Jigsaw

Nov 16, 2009
The palaeontologists’ puzzle - each of these conodont teeth is less than a millimetre long. Working out how the different shapes fitted together, and which were parts of the same skeleton is a complex problem.

(PhysOrg.com) -- A new study pitting academic expertise against a computer in recreating a 425 million-year old jigsaw puzzle has discovered that there is no substitute for wisdom born out of experience.

The research tested the reliability of expert identification versus in reconstructing fossils. The investigation, based on from extinct vertebrates, found that the most specialized experts provided the most reliable identifications.

University of Leicester researcher Dr Mark Purnell said: “Being a palaeontologist can be fun, but sometimes it isn’t easy. Take vertebrates, the group to which we belong. When a vertebrate animal dies, whether it’s a fish, a sabre-tooth cat or a dinosaur, the flesh rots away and the bones of the skeleton are usually scattered before being fossilised. In order to interpret them correctly, the palaeontologist must piece them back together, or at least work out which bits are which.

“This is difficult enough when you have modern relatives for comparison; but what if there’s nothing alive today that’s remotely like the extinct animal you need to analyse? It’s exactly like doing a jigsaw puzzle without a picture.”

This is what faces palaeontologists who study conodonts. Lead author David Jones, who carried out the study while at the University of Leicester, explains: “Earth’s oceans teemed with conodonts for 300 million years; they were the most common vertebrates around, and they were the first to evolve teeth. In fact the conodont skeleton was all teeth: a basket of hacksaw-shaped blades which was extended out of the mouth to grab prey, behind which lay pairs of slicing blades and crushing teeth - a set of gnashers straight out of Alien.”

Ancient marine rocks are often packed with hundreds or thousands of scattered conodont teeth, with many species jumbled up together.

“To make matters worse, within any one animal, teeth from different parts of the skeleton looked almost identical! Now we have a jigsaw puzzle with no picture, where each piece could go in different places. But just so it’s not too easy, conodont teeth are also microscopic, “said Dr Purnell, of the Department of Geology.

Traditionally, experts would wrestle with this puzzle based on their previous experience and comparison with more complete skeletons, but researchers investigated whether there is another way?

Four different types of conodont teeth from different species- pieces from different puzzles - mounted on a pinhead.

For the new study, published in the latest issue of the journal Palaeontology, David Jones and Mark Purnell, from the University of Leicester, teamed-up with Peter von Bitter from the Royal Ontario Museum, Canada, to bring sophisticated statistical techniques to bear on solving this skeletal jigsaw. They used material from a 425 million year old rock deposit in Ontario, Canada which, unlike almost all other deposits in the world, preserves both scattered teeth and complete skeletons of conodonts. This material allowed them to compare the success rate of experts in placing the teeth in the correct positions within the skeleton, with the success rate of computer-based methods.

So how do the experts stack up against the machines? “Pretty well” says Jones. “This is reassuring for palaeontologists! but the computer-based approach did at least as well and was also consistent; experts disagreed amongst themselves, and less experienced palaeontologists, not surprisingly, made more mistakes.

“The statistical techniques therefore allow us to test and verify the conclusions drawn by palaeontologists, greatly increasing the confidence with which we can reconstruct the skeletons of extinct vertebrates. But it’s not time to retire the experts; at least not yet...” say the researchers.

More information: The paper, “Morphological criteria for recognising homology in isolated skeletal elements: comparison of traditional and morphometric approaches in conodonts” by David Jones, Mark Purnell and Peter von Bitter is published in the current issue of Palaeontology.

Provided by University of Leicester (news : web)

Explore further: New branch added to European family tree

add to favorites email to friend print save as pdf

Related Stories

'Evolutionary leaps' questioned

May 18, 2005

New evidence from fossil fish, hundreds of millions of years old, casts doubt on the latest ideas about evolutionary theory. The research, by Dr Philip Donoghue of the University of Bristol and Dr Mark Pur ...

Biologists find gene network that gave rise to first tooth

Feb 10, 2009

A paper in this week's PLoS Biology reports that a common gene regulatory circuit controls the development of all dentitions, from the first teeth in the throats of jawless fishes that lived half a billion years ago, to the ...

Dino tooth sheds new light on ancient riddle

Jun 29, 2009

Microscopic analysis of scratches on dinosaur teeth has helped scientists unravel an ancient riddle of what a major group of dinosaurs ate- and exactly how they did it!

Teeth: a future renewable natural resource?

Nov 21, 2006

Most vertebrates have continuous tooth generation, meaning that lost teeth are replaced with new teeth. Mammals, however, including humans, have teeth that are generally only replaced once, when milk teeth are replaced with ...

Dinosaur reclassified as crocodile

Jun 23, 2005

University of California-Berkeley researchers say complete skeletons prove that Revueltosaurus callenderi was a relative of crocodiles -- not dinosaurs.

Recommended for you

New branch added to European family tree

13 hours ago

The setting: Europe, about 7,500 years ago. Agriculture was sweeping in from the Near East, bringing early farmers into contact with hunter-gatherers who had already been living in Europe for tens of thousands ...

'Hidden Treasure of Rome' project unveiled

Sep 16, 2014

For more than a century, hundreds of thousands of historical artifacts dating back to before the founding of Rome have been stored in crates in the Capitoline Museums of Rome, where they have remained mostly untouched. Now, ...

NOAA team reveals forgotten ghost ships off Golden Gate

Sep 16, 2014

A team of NOAA researchers today confirmed the discovery just outside San Francisco's Golden Gate strait of the 1910 shipwreck SS Selja and an unidentified early steam tugboat wreck tagged the "mystery wreck." ...

User comments : 0