Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Earliest tracks of 4-legged stroll

05.11.2004


Our four-legged, five-toed ancestors conquered the land earlier and more independently than expected, say paleontologists studying newfound 345 to 359-million-year-old tracks at an eroding beach in eastern Canada.

At least six different kinds of four-limbed reptile-like animals – a.k.a. tetrapods – with five digits on their feet left their tromping prints in the mud of what was once a tropical swamp at Blue Beach, Nova Scotia. The five-digit tracks range in size from four inches to less than an inch and seem to contradict the prevailing idea that the first tetrapods had wide variety of other-than-five-toed (polydactyl) feet, out of which five-toed (pentadactyl) animals later won out as the most efficient on land. "We’re talking about a fundamental question in the history of life," said paleontologist Spencer Lucas of the New Mexico Museum of Natural History and Science in Albuquerque. "We are talking about the origin of terrestriality. It’s from this conquest (of land) that we are here."

It’s also the evolutionary step that set the stage for our ten fingers and toes.



Research on the Blue Beach track discoveries by Lucas, Adrian Hunt, Chris Mansky and John Calder will be presented on Sunday morning, 7 Nov., at the annual meeting of the Geological Society of America in Denver. The tracks found in Blue Beach’s Horton Bluff formation appear to be from animals belonging to groups better known from fossil remains in later deposits, explained Lucas. "It shows that some of these groups of animals probably were around a lot earlier," he said.

The fact that all of the tracks at Blue Beach are five-toed suggests that pentadactyl tetrapods developed as a group quite early in the Carboniferous, tens of millions of years earlier than thought. They actually moved ahead of the pack, and were not survivors of the winnowing of polydactyl tetrapods. In other words, all those other-toed tetrapods might have been an evolutionary sideshow rather than the main stage out of which our pentadactyl ancestors evolved, says Lucas. The discovery also highlights the great value of what has long been an underappreciated track site. "Nova Scotia is the Rosetta Stone for Carboniferous footprints," Lucas said.

It’s also a great opportunity to see how bringing together information from fossil tracks and later fossil bones can illuminate critical evolutionary stages. Unlike fossil skeletons, tracks tell a lot about how an animal behaved and moved – as well as hint at their anatomy. "I think what’s exciting is that (tracks) show things that the bone record doesn’t," Lucas said. "I’ve come to see how much more you get when you consider both records."

Also making the Blue Beach site unique is how it is excavated, Lucas pointed out. Instead of being a slow, controlled excavation of layers of rock, the ocean is in control. Researchers have to time their work around tides and surf which are rapidly eroding the bluffs and continually exposing new tracks. Most of the fossil tracks have been collected by Blue Beach local Chris Mansky who is able to walk the beach regularly and collect specimens as Nature offers them up.

The Oldest Tetrapod Footprint Ichnofauna, From the Lower Mississippian Horton Bluff Formation, Nova Scotia, Canada. Sunday, 7 November, 8:00 a.m.-12:00 p.m., CCC Exhibit Hall. Abstract may be viewed at: http://gsa.confex.com/gsa/2004AM/finalprogram/abstract_77934.htm.

Ann Cairns | EurekAlert!
Further information:
http://www.geosociety.org

More articles from Earth Sciences:

nachricht Radioactivity from oil and gas wastewater persists in Pennsylvania stream sediments
22.01.2018 | Duke University

nachricht World’s oldest known oxygen oasis discovered
18.01.2018 | Eberhard Karls Universität Tübingen

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Thanks for the memory: NIST takes a deep look at memristors

22.01.2018 | Materials Sciences

Radioactivity from oil and gas wastewater persists in Pennsylvania stream sediments

22.01.2018 | Earth Sciences

Saarland University bioinformaticians compute gene sequences inherited from each parent

22.01.2018 | Life Sciences

VideoLinks Wissenschaft & Forschung
Overview of more VideoLinks >>>