Scientists Find Lamprey A 'Living Fossil': 360 Million-year-old Fish Hasn't Evolved Much

Scientists from the University of Witwatersrand in Johannesburg, South Africa, and the University of Chicago have uncovered a remarkably well-preserved fossil lamprey from the Devonian period that reveals today's lampreys as "living fossils" since they have remained largely unaltered for 360 million years. The scientists describe the new find in the article, "A lamprey from the Devonian of South Africa," to be published in the Oct. 26, 2006, issue of Nature. (Image courtesy of University of Chicago Medical Center) Chicago's Michael Coates, PhD, joined Witwatersrand's Bruce Rubidge, PhD, and graduate student and lead author Rob Gess to describe the new find in the article, "A lamprey from the Devonian of South Africa" to be published in the Oct. 26, 2006, issue of Nature.

"Apart from being the oldest fossil lamprey yet discovered, this fossil shows that lampreys have been parasitic for at least 360 million years," said Rubidge, director of the Bernard Price Institute for Palaeontological Research.

Lampreys are long, eel-like parasites that attach themselves to and feed on other fish. Of the 46,000 known species of vertebrates, lampreys and hagfish are the only surviving jawless vertebrates. Lampreys are the most "primitive" of the vertebrates, meaning that they are the least changed from the first vertebrates. Besides lacking jaws, lampreys have no paired pectoral and pelvic fins, and no scales.

"This fossil changes how we look at lampreys today," said Coates, associate professor of organismal biology and anatomy. "They're very ancient, very primitive animals, yet with highly specialized feeding habits."

It reveals that the anatomical evolution of lampreys is more conservative than scientists thought, Coates added. Although they've gotten slightly longer, they specialized early and successfully and thus appeared to have stayed much the same for the past 360 million years.

"This discovery is a monument to the dedication and passion of [Gess], who has spent many months patiently excavating and unearthing the elusive secrets from the prehistoric past," Rubidge said.

Gess found the new specimen, Priscomyzon riniensis, 18 months ago in an ancient estuary in Grahamstown, South Africa. Preserved showing the underside, the fossil measures less than 2 inches long and reveals a set of 14 teeth surrounding the mouth that is proportionately larger than its descendents today.

"The most striking feature of Priscomyzon is its large oral disc, edged with a soft outer lip, supported by an annular cartilage, and surrounding a circular mouth," the authors wrote. "This is the first clear evidence of a Palaeozoic lamprey with an oral disc."

According to the scientists, this find greatly adds to what was a severely limited lamprey fossil record and, for the first time, places the origin of modern lamprey morphology deep within the Palaeozoic period. It adds essential new detail to the emerging and changing picture of early vertebrate evolution.

Until now, the lamprey fossil record included only those that show a side view but reveal little of the gill basket and feeding apparatus. However, earlier this year, Nature reported on a freshwater lamprey fossil found in the Jehol biota of China (Inner Mongolia) from the Early Cretaceous period (about 125 million years ago).

The newly discovered South African fossil shows that these anatomically specialized fish are "holdovers" from ancient marine ecosystems, Coates said. Obviously exceptional survivors, these animals predate the advent of modern fish and have survived at least four major extinction events.

"There are few representatives of these early branches in vertebrate evolution that are still around today," Coates said, which is why so much scientific attention has been paid to lampreys. Although highly specialized in their own right, these primitive animals are used as surrogate ancestors for comparative research on living jawed vertebrates.

"It gives us a calibration point," Coates said. "We study lampreys because, in many respects, they're so primitive. They never had jaws, they never had [true] teeth, they never had fins, they never had limbs. Lampreys provide a glimpse of conditions early in vertebrate evolutionary history."

Because lampreys do not have bone or any substantial cartilage, they are extremely rare as fossils. This fossil not only reveals a nearly complete soft tissue impression, but it also pushes back their fossil record another 35 million years.

"These are pretty insubstantial animals," Coates said. "Lacking a boney skeleton, they rot down, leaving no hard parts, like a skull or ribs. So if a fossil site is discovered that yields impressions of the delicate remains of these animals, then this site needs to be explored thoroughly for other examples of exceptional preservation."

The scientists will continue to sort through much of the indeterminate material that is emerging from the ongoing dig.

Nearly 50 species of lampreys are found today in temperate rivers and coastal seas. Some species live in fresh water for their entire lives, but most are anadromous, hatching in fresh water, migrating to the ocean to grow and mature, and migrating back to fresh water to spawn and reproduce.

When adult lampreys return to fresh water, they stop feeding during winter and spawn the following spring. Eggs hatch after approximately three weeks and become blind larvae, called ammocoetes. After four to seven years, the ammocoetes metamorphose into juvenile lampreys called macropthalmia, which migrate out to the ocean and become parasitic adult lampreys, living just a year or two and growing up to 2 feet long.

Abundant in the Northeast United States, lampreys have a sucker-like mouth with a ring of cartilage that supports the rim of the mouth. It fastens on to a living fish with its teeth, rasps at the host's soft tissues with its piston-like tongue, produces strands of mucus to trap the food and feeds on the body fluids. A fish attacked by lampreys may be severely injured or even killed.

Thanks for the ping. Here's an oldie about a different eel:

Europe's Eels Are Slipping Away, Scientists Warn
by James Owen
October 9, 2003
Scientists there reported that the number of juvenile European eels (Anguilla anguilla) reaching rivers from their mid-Atlantic nursery grounds has crashed 99 percent since the 1970s. The closely-related American eel (Anguilla rostrata) and Japanese eel (Anguilla japonica) are also threatened with extinction, experts reported... [T]here are those whose jobs depend on eels, some 25,000 fishermen in Europe alone... [D]ams, pollution, overfishing, invasive parasite species, and ocean warming have been identified as possible causes... Despite its widespread distribution and commercial importance, the life cycle of the European eel remains clouded in mystery... Remarkably, nobody has been able to locate the eels' final destination, although experts believe eels mate and die in the millions somewhere in the Sargasso Sea, a becalmed expanse of the mid-Atlantic Ocean up to three miles (five kilometers) deep. (American eels are also thought to spawn there.)

The late Otto Muck might have called this one, as he claimed that the life cycle of the eels was disrupted by the sinking of Atlantis. Of course, the impact of his supposed asteroid might have curtailed their activities quite a bit long before that. ;')

"...If there were events in the real world that violated evolution--say, a creature that was half mammal, half fish, or fossils occurring out of order in well-dated strata--then the theory evolution would conflict with the evidence...."

Somehow, I have a feeling that such violations would be wildly acclaimed as 'transitional forms'...

"...Every physics experiment we do likewise supports the conservation of momentum, but that doesn't seem to bother you...."

Well, let me carry your analogy a little farther. At one time, Newtonian physics seemed pretty complete, because that's where we live. Approach the speed of light, however, and mass begins to do funny things. Likewise in a lot of 'steady state' situations, there are 'edge effects' so that a system near it's limits does not behave as expected. (From your screen name, I assume you know this, but I am including it for those who may not have your background, and to make sure my argument appears complete in print.)

Despite all our knowledge, despite all we think we know, we are talking about the distant past, here, perhaps as some of us believe, the beginning of time itself. Now, extrapolation near the edges may not be as we expect it. Our problem is that we cannot KNOW if that is so or not, but some insist we DO KNOW. I insist none of us do.

Evolutionists believe what fossils and their intellects tell them. Creationists, while some have intellects just as potent, choose to believe what our Creator tells us. Some of us are just more thoughtful and less confrontational than others.

"You have not accurately portrayed the explanations and responses given on this discussion."

I believe I have. Despite being a Bible-believing Creationist, I do indeed have a normal IQ, perhaps even above average. I also have a talent for understanding even the most convoluted communications and stating (accurately) the bottom line.

Your colleagues have already confirmed some of my claims in their replies, allowing that these discoveries are indeed placed into a template which pre-supposes evolution as fact.

"First of all, I'm not going to call you names. I find the pride and the name-calling more prevalent among the creationists, so I'll leave that to them."

OK - sorry. I've been on many threads which label folks who post and leave as having no courage, or worse. Point taken.

"You said, "no matter what the fossil record shows, it supports evolution." ... A more accurate version of your statement would be, ... "

Careful. I say what I mean. Please don't try to help me be more 'accurate'. I hit it pretty much on the head, according to your very own words, in the very same reply! :

"...we must constantly start with the premise that evolution is involved, or else all we have left is divine intervention. "

Careful. I say what I mean. Please don't try to help me be more 'accurate'. I hit it pretty much on the head, according to your very own words, in the very same reply! :
"...we must constantly start with the premise that evolution is involved, or else all we have left is divine intervention. "

Thank you. You've reiterated my point that the alternative to inquiry is simply pawning everything off on "God did it". Well, I happen to believe that God was involved. I'm also intensely curious about the mechanism that He used, and I believe it's not beyond His capacity to set a billions-of-years process in motion to bring us about.

and I believe it's not beyond His capacity to set a billions-of-years process in motion to bring us about.

And I believe, as the Bible states, that it is not beyond God's capability to say "Let there be..." and there was.

Bingo, taxesareforever.

SlowBoat, I held your view for a VERY short time when I was young. However, I felt it smacked of compromise with the world, and abandoned it pretty quickly.

I don't the Bible teaches that our salvation hangs on how we view the theory of evolution, but I do believe being the brunt of scorn because I believe God created everything immediately is not a bad thing.

God says His ways are not our ways. The fact that unbelievers have to believe in evolution or the big bang, or some such in order to deny God, makes me lean toward a literal understanding of Genesis. Please note, I did NOT say that all TOE supporters are unbelievers.

And I believe that God gave us our senses and our reason for a purpose. I've seen the arguments on both sides, and the evidence before me argues more for an Earth that is 5 billion years old, and for mankind having evolved, than it does for an Earth that is merely 6000 years old.

People spend far too much time parsing the Bible, trying to define every part of the material world by it. It is about our spiritual lives, and about our relationship with God through Jesus.

I promised myself I wouldn't argue on the crevo threads any more. Now I remember why. Enjoy. Say what you like about or to me. I've said my peace.

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.