Rare insect fossil reveals 100 million years of evolutionary stasis

Feb 03, 2011
A fossil found in northeastern Brazil confirmed that the splay-footed cricket of today has at least a 100-million-year-old pedigree. Credit: Hwaja Goetz

Researchers have discovered the 100 million-year-old ancestor of a group of large, carnivorous, cricket-like insects that still live today in southern Asia, northern Indochina and Africa. The new find, in a limestone fossil bed in northeastern Brazil, corrects the mistaken classification of another fossil of this type and reveals that the genus has undergone very little evolutionary change since the Early Cretaceous Period, a time of dinosaurs just before the breakup of the supercontinent Gondwana.

The findings are described in a paper in the open access journal ZooKeys.

"Schizodactylidae, or splay-footed crickets, are an unusual group of large, fearsome-looking related to the true crickets, katydids and grasshoppers, in the order Orthoptera," said University of Illinois entomologist and lead author Sam Heads, of the Illinois Natural History Survey. "They get their common name from the large, paddle-like projections on their feet, which help support their large bodies as they move around their sandy habitats, hunting down prey."

Although the fossil is distinct from today's splay-footed crickets, its general features differ very little, Heads said, revealing that the genus has been in a period of "evolutionary stasis" for at least the last 100 million years.

Other studies have determined that the region where the fossil was found was most likely an arid or semi-arid monsoonal environment during the Early Cretaceous Period, Heads said, "suggesting that the habitat preferences of Schizodactylus have changed little in over 100 million years."

Explore further: Earlier Stone Age artifacts found in Northern Cape of South Africa

More information: The paper, "On the Placement of the Cretaceous Orthopteran Brauckmanni groeningae From Brazil, With Notes on the Relationships of Schizodactylidae (Orthoptera, Ensifera)," is available online.

Related Stories

Fossil of Cretaceous-era squid found in Peru

Jan 20, 2011

Paleontologists said Thursday they discovered the 85-million-year-old fossil of a previously unknown squid species from the Cretaceous era in the high jungle region of northeastern Peru.

Can modern-day plants trace their New Zealand ancestry?

Jan 21, 2010

One hundred million years ago the earth looked very different from how it does today. Continents were joining and breaking apart, dinosaurs were roaming the earth, and flowering plants were becoming more widespread.

Why certain fishes went extinct 65 million years ago

Mar 26, 2009

Large size and a fast bite spelled doom for bony fishes during the last mass extinction 65 million years ago, according to a new study to be published March 31, 2009, in the Proceedings of the National Ac ...

Recommended for you

West US cave with fossil secrets to be excavated

Jul 24, 2014

(AP)—For the first time in three decades, paleontologists are about to revisit one of North America's most remarkable troves of ancient fossils: The bones of tens of thousands of animals piled at the bottom ...

Radar search to find lost Aboriginal burial site

Jul 22, 2014

Scientists said Tuesday they hope that radar technology will help them find a century-old Aboriginal burial ground on an Australian island, bringing some closure to the local indigenous population.

User comments : 31

Adjust slider to filter visible comments by rank

Display comments: newest first

LariAnn
1.2 / 5 (18) Feb 03, 2011
IMHO, this observation makes me wonder about evolution. To me, the phrase, "evolutionary stasis" should be an oxymoron. Evolution is not supposed to be "stasis"! Environments do change a lot in 100 million years, meaning to me that this cricket should have undergone changes as well. Unless the habitat remained static for 100 million years, it seems impossibly unlikely that this organism would have remained basically unchanged through all that time. Adaptive changes in other organisms have been observed in historical time (as contrasted with geological time) so give it 100 million years and surely that cricket should have morphed into some kind of grasshopper or other insect! That is, unless the prevailing assumptions in evolutionary biology require extensive revision.
Dokudango
4.3 / 5 (11) Feb 03, 2011
Just because the physical morphology hasn't changed much, doesn't mean that this poses a "problem" with evolution. Perhaps its morphology was something that worked well with its environment. Keep in mind that although the way it looks may not have changed, it's genome could be much different.
Temple
4.7 / 5 (13) Feb 03, 2011
Remember that evolution doesn't lead to 'perfect' adaptation to an environment. It is a method of selecting the mutations which offer best chances of being passed down through reproduction.

Also recall that, even if mutations spawn new species or even whole new branches off the evolutionary tree, that doesn't mean that the original species will be wiped out by the new sub-species' selective pressure.

That we still have amoebas in no way invalidates the evolutionary model.
trekgeek1
4.6 / 5 (10) Feb 03, 2011
Bugs and insects probably don't feel environmental change as much as larger surface dwelling animals. Small insects can live underground where the environment doesn't change as much.

Although the fossil is distinct from today's splay-footed crickets, its general features differ very little, Heads said, revealing that the genus has been in a period of "evolutionary stasis" for at least the last 100 million years.


You see that it has changed, even visibly. They are not saying it is the exact same. Additionally, it is difficult to see what has changed internally. The exoskeleton is purely mechanical and may have served well in many types of environment. More adaptations may have occurred in internal features that are not as well preserved.
Terrible_Bohr
4.9 / 5 (14) Feb 03, 2011
Look at sharks and crocodiles: both have remained very much the same for 150 million years. This cricket is hardly problematic or remarkable.
gvgoebel
5 / 5 (10) Feb 03, 2011
Oh dear: "If humans evolved from monkeys, why are there still monkeys?!!!!one!!!eleven!!"

There is a saying in engineering: "If it works, don't mess with it." Works in evolutionary science, too.
jsn3604
1.1 / 5 (7) Feb 03, 2011
Reminds me of how we came from Africa 200,000 year ago until we found possible tooth fragments from a human in Israel 400,000 years ago.
DaffyDuck
not rated yet Feb 03, 2011
It's not difficult to imagine how the species remained unchanged. First of all remember that evolution is branching so it's likely that other species branched off of this one as they found themselves in different environments. Still, some of the original species managed to move so they remained in the environment they were used to and therefore had few changes in selective pressure.
jsn3604
not rated yet Feb 04, 2011
But thats the point. Isn't there supposed to be an error rate when DNA is copied (i.e., mutation and natural selection)? It shouldn't matter whether the environment changed or not. In fact, I've read that most of the history of life on Earth consisted of single celled organisms. What "environmental change" caused them jump to Precambrian complexity?
PaulieMac
not rated yet Feb 04, 2011
Reminds me of how we came from Africa 200,000 year ago until we found possible tooth fragments from a human in Israel 400,000 years ago.


Umm - it does? In what way?
jmcanoy1860
5 / 5 (4) Feb 04, 2011
Reminds me of how we came from Africa 200,000 year ago until we found possible tooth fragments from a human in Israel 400,000 years ago.


Umm - it does? In what way?


Because the earth is the center of the universe, is flat, sits on pedestals, and was protected by a magic entirely transparent crystal space shield. Duh. And then flooded.
NameIsNotNick
not rated yet Feb 04, 2011
To me, the phrase, "evolutionary stasis" should be an oxymoron. Evolution is not supposed to be "stasis"!

No it's not. Evolutionary stasis is common. If you would like to learn more about how evolution actually works, I would recommend "The Greatest Show on Earth" by Richard Dawkins as a very informative and entertaining read.
Skeptic_Heretic
4.3 / 5 (4) Feb 04, 2011
Reminds me of how we came from Africa 200,000 year ago until we found possible tooth fragments from a human in Israel 400,000 years ago.
Umm - it does? In what way?

Because the earth is the center of the universe, is flat, sits on pedestals, and was protected by a magic entirely transparent crystal space shield. Duh. And then flooded.
You could have just said "This research looks like a paradigm shift." You didn't have to be a cunt about it, that is, unless you're actually a creationist, in which case you are a cunt:)
jsn3604
1 / 5 (7) Feb 04, 2011
I will admit that I was a bit curious as to how a dove could find an intact olive branch after the whole world flooded, but evolutionary model of how all life on Earth originated can be just as inconsistent. Claiming random mutation guided by natural selection, then claiming "convergent evolution" to justify instances where the same random mutation happens more than once. As far as Richard Dawkins, hes just another ex-Christian angry at his former faith and just looking for evidence to prove it wrong like most Evolutionists. How can you trust the "unbiased" data collected from a man who spends his free time bashing his former faith through books and speeches. Emotion has likely clouded his rational judgement (i.e., scientific abilities). I though the Milgram experiment taught people not to blindly trust someone just because they were wearing a lab coat.
gvgoebel
5 / 5 (5) Feb 04, 2011
Claiming random mutation guided by natural selection, then claiming "convergent evolution" to justify instances where the same random mutation happens more than once.


Hmm? That is a very unusual case and really only arises under very constrained circumstances: for example, dichromats (2 color vision) mammals going to trichromats (3 color) by gene duplication, where there's only
a limited number of possibly mutations that can produce the third color genes. Usually convergent evolution at the molecular level results in different, sometimes very different solutions.

When genes get broken -- loss of vision in cave creatures and the like -- the breakages are all over the map. Broken genes are difficult to explain by anything but evolutionary selection (BTW), or more properly its removal.

As far as Dawkins goes, I trust his science, and the man can WRITE -- but I tend to find his, ah, other views not of much personal interest and don't pay them much mind.
frajo
5 / 5 (1) Feb 04, 2011
I though the Milgram experiment taught people not to blindly trust someone just because they were wearing a lab coat.
No. The Milgram experiment taught us that most people do trust authorities regardless of the damage they inflict on third persons.
jsn3604
1 / 5 (6) Feb 04, 2011
Hmm? That is a very unusual case and really only arises under very constrained circumstances: for example, dichromats (2 color vision) mammals going to trichromats (3 color) by gene duplication, where there's only
a limited number of possibly mutations that can produce the third color genes. Usually convergent evolution at the molecular level results in different, sometimes very different solutions.



Well I certainly appreciate your logical response. In addition to convergent evolution, there are also examples of parallel evolution as well. I'm sure Dawkins has brilliance and science has really contributed to the well being of humanity, but I also know the scientific community has its issues. There is a money and reputation side of science.
frajo
5 / 5 (3) Feb 04, 2011
hes just another ex-Christian angry at his former faith and just looking for evidence to prove it wrong like most Evolutionists.
No. Every scientist knows that faith is neither verifiable nor falsifiable.
gvgoebel
5 / 5 (7) Feb 04, 2011
There is a money and reputation side of science.


In the first place, NOBODY becomes a scientist to make big money. If you want to make money, you go into business.

As far as reputation goes: "Pride makes some people foolish, and prevents others from becoming so."

Among scientists, it is clearly bad form to misrepresent evidence or refuse to acknowledge error when it becomes obvious. They don't always live up to that standard -- but among the enemies of science, it seems to be less "bad form" than "standard operating procedure".
jsn3604
1 / 5 (4) Feb 04, 2011
In the first place, NOBODY becomes a scientist to make big money. If you want to make money, you go into business.


I was referring to research money needed to actually conduct the experiments. If you were a scientist and you came up with a hypothesis completely outside of mainstream science, how easy would it be for you to get the funding necessary to conduct the experiments? Would scientists even risk a hypothesis outside of mainstream and "fashionable" science in order to prevent risking their reputation and livelihood?
gvgoebel
5 / 5 (3) Feb 04, 2011
Would scientists even risk a hypothesis outside of mainstream and "fashionable" science in order to prevent risking their reputation and livelihood?


Actually, from what I've seen controversial scientific issues are usually at the top of the research agenda. For example, is there dark matter / dark energy or not?

Granted, you might have problems with ideas that have long been unfashionable. I don't think a scientist working on phlogiston theory or elan vital would find it easy to get funding.

jsn3604
1 / 5 (2) Feb 05, 2011
Would scientists even risk a hypothesis outside of mainstream and "fashionable" science in order to prevent risking their reputation and livelihood?


Actually, from what I've seen controversial scientific issues are usually at the top of the research agenda. For example, is there dark matter / dark energy or not?

Granted, you might have problems with ideas that have long been unfashionable. I don't think a scientist working on phlogiston theory or elan vital would find it easy to get funding.



Thats because there is observational data to suggest the existence dark energy and dark matter via astronomy. That is not really controversial. Controversial would be "cold fusion" or even more taboo (perpetual motion). Even if you did have a mathematical model showing feasibility of cold fusion, due you really think you could get a government grant or venture capitalist funds on something that now has negative connotations?
frajo
not rated yet Feb 05, 2011
If you were a scientist and you came up with a hypothesis completely outside of mainstream science, how easy would it be for you to get the funding necessary to conduct the experiments?
You are contriving the unreal case of an experimenter with an off-mainstream hypothesis. In reality it's the other way round: Off-mainstream hypotheses are the weekend work of theorists who are paid for their on-duty research and education. Experimenters, otoh, are people with lots of hands-on experience and access to all of the expensive machinery. They don't concoct off-mainstream hypotheses on their own.
The lonesome genius who finds a revolutionary hypothesis all of his own and all of a sudden needs 10 million bucks for testing doesn't exist in reality.
gvgoebel
5 / 5 (2) Feb 05, 2011
Controversial would be "cold fusion" or even more taboo (perpetual motion).


"Perpetual motion" -- is this some sort of a joke, or are you just off your meds?
frajo
4 / 5 (2) Feb 05, 2011
Thats because there is observational data to suggest the existence dark energy and dark matter via astronomy. That is not really controversial.
You seem not to be very well informed about the ongoing discussions about DM, DE, inflation, and the BigBang concept.
Controversial would be "cold fusion"
What's controversial about cold fusion? Find some theory that explains CF or show an independently reproducible machine working with CF.
or even more taboo (perpetual motion).
Very easy: Which theory allows PM? Which machine works on PM?
Even if you did have a mathematical model showing feasibility of cold fusion, due you really think you could get a government grant or venture capitalist funds on something that now has negative connotations?
When you have a mathematical model you'll convince your fellow mathematicians and physicists in a first step.
But if you just have a business model try to convince venture capitalists, not scientists.
gvgoebel
5 / 5 (4) Feb 05, 2011
But if you just have a business model try to convince venture capitalists, not scientists.


Ah, the business model for perpetual-motion machines is very well-established: "Take the money and run."
Skeptic_Heretic
not rated yet Feb 05, 2011
In the first place, NOBODY becomes a scientist to make big money. If you want to make money, you go into business.


I was referring to research money needed to actually conduct the experiments. If you were a scientist and you came up with a hypothesis completely outside of mainstream science, how easy would it be for you to get the funding necessary to conduct the experiments? Would scientists even risk a hypothesis outside of mainstream and "fashionable" science in order to prevent risking their reputation and livelihood?

Have you heard of youtube?

I won a grant for a study 5 years ago by making a video outlining the concept of the experiment. It caught a few people's attention and I recevied a low but appropriate amount of funding to commit the study.
ekim
5 / 5 (1) Feb 06, 2011
Count less times we see convergent evolution. Animals will evolve to occupy a niche in an environment and take on certain characteristics which provide benefits. An example of this would be the elephant shrew, genetically closer to elephants than shrews. Why should we be impressed when an animal remains in an optimal form for a certain environment?
ubavontuba
1 / 5 (1) Feb 06, 2011
Here, you can see this fossil and the modern splay-footed cricket side by side:

http:/s8int.com/WordPress/?p=2594

It could be due to flattening, but the legs of the fossil look slightly more robust.

It certainly seems odd these things can survive, essentially unchanged, for so long.
Johannes414
1 / 5 (3) Feb 15, 2011
This animal did not change because it knew evolution is just bogus.
Ethelred
5 / 5 (1) Feb 17, 2011
Actually it didn't change much much evolutionary pressures maintained its shape. Evolution has no goal except survival and if remained similar is what is needed to survive than that is what will happen.

Now would you care to give some support for YOUR beliefs. Like when the Flood was.

Ethelred