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Meet the Saber-Toothed Squirrel

samzenpus posted more than 2 years ago | from the we're-going-to-need-a-bigger-acorn dept.

Earth 59

sciencehabit writes "Researchers have discovered the fossil remains of a 94-million-year-old squirrel-like critter with a long, narrow snout and a pair of curved saber-fangs that it would have likely used to pierce its insect prey. The creature, pieced together from skull fragments unearthed in Argentina and dubbed Cronopio dentiacutus, was not ancestral to us or any living mammal. Instead, it belonged to an extinct group called dryolestoids, a cadre of fuzzy mammals that scurried about in the shadow of long-necked dinosaurs."

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Did they find? (5, Funny)

camperdave (969942) | more than 2 years ago | (#37942566)

Did they find it clutching a fossilized acorn?

Re:Did they find? (1)

bryan1945 (301828) | more than 2 years ago | (#37942654)

Darn you beat me to it! Love that little guy.

Re:Did they find? (1)

owlstead (636356) | more than 2 years ago | (#37943082)

Don't feel bad, the subtitle and of course the article beat both of you to it....

Re:Did they find? (2)

owlstead (636356) | more than 2 years ago | (#37943042)

No, it is actually *in the article* that it didn't.

Re:Did they find? (2)

Cryacin (657549) | more than 2 years ago | (#37943078)

You must be a real hoot at parties.

Re:Did they find? (1)

planimal (2454610) | more than 2 years ago | (#37943222)

you must be that douche who calls stupid people out when they make misinformed affirmations?

Re:Did they find? (1)

jd (1658) | more than 2 years ago | (#37944218)

I think it's owls that hoot. Squirrels make more of a chittering sound.

Re:Did they find? (1)

jd (1658) | more than 2 years ago | (#37944222)

Bah. Just noticed the username. Never mind.

Re:Did they find? (1)

RockDoctor (15477) | more than 2 years ago | (#37956406)

Happens to the best of us.

(I was thinking of making a comment too, since I go by the nickname of "Wol" in Real Life (TM). So your trip up saved me <G>.)

Re:Did they find? (1)

wallsg (58203) | more than 2 years ago | (#37955988)

No, it is actually *in the article* that it didn't.

On Slashdot that's the best place to hide something that you don't want read...

Re:Did they find? (-1)

Anonymous Coward | more than 2 years ago | (#37943202)

No, fucknuts. It ate insects.

Re:Did they find? (0)

Anonymous Coward | more than 2 years ago | (#37944172)

it was clutching fucknuts?

Re:Did they find? (1)

Gilmoure (18428) | more than 2 years ago | (#37947176)

I think it couldn't find any fucknuts. It had to wait for SlashDot to be invented.

As a matter of fact... (1)

Dogbertius (1333565) | more than 2 years ago | (#37947156)

They did! []

Bah! (1)

Black Parrot (19622) | more than 2 years ago | (#37942586)

I'll bet this one didn't "scurry about". Probably the dinosaurs scurried away whenever it came out of its den looking hungry.

Re:Bah! (1)

black6host (469985) | more than 2 years ago | (#37942720)

With a skull about an inch long, I doubt it.

Re:Bah! (2)

R3d M3rcury (871886) | more than 2 years ago | (#37942960)

Oh, it's just a harmless little squirrel, isn't it? Well, it's always the same. But do they listen to me?

Those dinosaurs better not risk a frontal assault. That squirrel's dynamite!

(ref [] )

Re:Bah! (1)

Velox_SwiftFox (57902) | more than 2 years ago | (#37943744)

Of course, we have no way of knowing if it is venomous.

Re:Bah! (1)

craigminah (1885846) | more than 2 years ago | (#37945848)

The only venomous mammal is the platypus.

Re:Bah! (1)

MaskedSlacker (911878) | more than 2 years ago | (#37947804)

And, presumably, at least some of it's extinct ancestors, and their extinct relatives. Who knows how far back mammalian venom goes?

Re:Bah! (1)

Uncle Warthog (311922) | more than 2 years ago | (#37949848)

The only venomous mammal is the platypus.

That's funny, I don't remember my lawyer as having webbed feet or a bill........

Re:Bah! (1)

oldmac31310 (1845668) | more than 2 years ago | (#37951070)

Oh, I remember the bill alright...

Re:Bah! (1)

Velox_SwiftFox (57902) | more than 2 years ago | (#37950876)

And shrews, and Cuban Solenodons, and European moles

Re:Bah! (0)

Anonymous Coward | more than 2 years ago | (#37945724)

I'll bet that the specimen is not native to the area, it was almost certainly carried there by a swallow.

Re:Bah! (1)

Anonymous Coward | more than 2 years ago | (#37945810)

African or European swallow ?

Re:Bah! (0)

Anonymous Coward | more than 2 years ago | (#37950148)

How am I supposed to know that?

Re:Bah! (0)

Anonymous Coward | more than 2 years ago | (#37944026)

Watch out for stobor.

Re:Bah! (1)

Gilmoure (18428) | more than 2 years ago | (#37947192)

*golf clap*

Re:Bah! (1)

owlstead (636356) | more than 2 years ago | (#37943064)

Of course it scurried, it could get up to 94 million years old. I'll see how well you run after reaching that age.

Already Discovered in Tennessee! (2)

Mister Transistor (259842) | more than 2 years ago | (#37942592)

Yes, it's called a Jackalope - did it have antlers, too?

Re:Already Discovered in Tennessee! (1)

Loligo (12021) | more than 2 years ago | (#37945446)

Such a dumb name. Anyone that's ever seen one knows they're clearly jackadeer.

Link-whore headline (1)

Anonymous Coward | more than 2 years ago | (#37942614)

There's no more or less relation to squirrels than any other modern rodent-like mammal. This isn't science, it's marketing.

Re:Link-whore headline (1)

Anonymous Coward | more than 2 years ago | (#37942664)

Indeed. And if the artist's rendition is anything to go by (which it probably isn't) it looks more like a shrew than a squirrel.

All you can state are probabilities. (1)

jd (1658) | more than 2 years ago | (#37944252)

Tsk! We don't know the genetic distance between this species and squirrels, all you can say is that squirrels aren't direct ancestors and therefore the genetic distance can't be any less than that between squirrels and the common ancestor of all modern rodentia. It can certainly be smaller than the genetic distance between squirrels and rodent-like animals that provably have a TMRCA of comparable age - mammals were quite diverse 94 million yeas ago and this new species may well be from a sub-branch off the branch that eventually became squirrels. Nothing in TFA to prohibit that, although it's a little unlikely.

You stating certainties where you have none is a far worse example of KWing than the headline.

:D (1)

buanzo (542591) | more than 2 years ago | (#37942688)

Argentina! Argentina! Argentina! Argentina! Couldn't help it. Sorry guys. Live long and prosper.

Re::D (0)

Anonymous Coward | more than 2 years ago | (#37942918)

We've got better dinosaurs too


Re::D (-1)

Anonymous Coward | more than 2 years ago | (#37943044)

argentina is full of peronists and negros villeros, argentina needs some thermonuclear bombs in the casa rosada, riBer, boca, villas 31 and 1-11-14.

fuck the queen of negros, kristina .. que muera la hija de puta!

Re::D (0)

Anonymous Coward | more than 2 years ago | (#37943166)

peronists? Italian beer-drinkers?

Re::D (1)

mruizcamauer (551400) | more than 2 years ago | (#37945838)

And of course the K govt will say its only 8 yrs old, not 94M, and they are responsible for finding it....

Scrat lives (0)

Anonymous Coward | more than 2 years ago | (#37943216)

Peter de Sève beat them to it. []

why is it compared to a squirrel? (1)

OrangeTide (124937) | more than 2 years ago | (#37943692)

looks like a weasel with ever so slightly longer teeth

Re:why is it compared to a squirrel? (1)

jc42 (318812) | more than 2 years ago | (#37943864)

Yeah; a quick google shows that it's classified in the extinct superorder Dryolestoidea, which has an unclear relationship to modern mammals. It certainly wasn't a rodent, which are in the Euarchontoglires superorder. The rodents themselves split off from that branch a few tens of millions of years later.

This sort of bizarre misclasification, apparently for the thrill of being able to write "sabre-toothed squirrel", doesn't exactly give a lot of credibility to the article's author.

The most appropriate response to this is probably "WTF is this doing on a news-for-nerds site?"

Re:why is it compared to a squirrel? (1)

jd (1658) | more than 2 years ago | (#37944292)

It's unclear and therefore the superorder (which is morphic, not genetic, and therefore almost certainly wrong -- traditional classifications tend not to hold up under genetic scrutiny) is immaterial.

Second, it's on here because it's a discovery of a new species. That's a particularly interesting part of science. Linking it with squirrels was no worse a travesty than chaos mathematicians linking storms and butterflies, and certainly no worse than plasma physicists talking of sausage instabilities. Nobody is trying to forecast the weather by studying insects and nobody is trying to cook breakfast in a nuclear fusion facility. I'll agree that Joe Average might be confused, but Joe Average certainly has no business being on a news-for-nerds site.

Re:why is it compared to a squirrel? (1)

OrangeTide (124937) | more than 2 years ago | (#37944696)

Nobody said it was a travesty. I just think it's weird and couldn't understand the logical reasoning behind the article's catchy title.

Re:why is it compared to a squirrel? (1)

jd (1658) | more than 2 years ago | (#37945220)

The logic is easy. Nobody reads the Firehose, so only catchy titles ever get spotted, and even fewer submit stories in the first place. (It's complex. Or, in some cases, wholly imaginary.)

Re:why is it compared to a squirrel? (0)

Anonymous Coward | more than 2 years ago | (#37950650)

It's unclear and therefore the superorder (which is morphic, not genetic, and therefore almost certainly wrong -- traditional classifications tend not to hold up under genetic scrutiny) is immaterial.

Tut tut. As a paleontologist who has to rely on morphological data for systematics, I think not so much! The relationships here were supported by a morphological cladistics analysis with more than 300 characters. Sure, not as great as molecular phylogenetics, but I think we should be very much shocked if it turned out it was actually a relative of the true squirrel. Perhaps it may be more meaningful to talk about what it had in common with 'squirrels'... which appears to have just been that it was a similar sized mammal. Given the post-cranial skeleton isn't known, we don't even know if it had a bushy squirrel tail!

They could have called it a "saber-toothed rat" and have been just as correct.

And anyway, I really doubt that "traditional" (Linnean?) systematics is all bad. I'd bet that if one compared what we thought we knew about relationships in 1960 with what we know about relationships among organisms today, we would find that many of the relationships have held up, more or less. Some small minority of inferred relationships have radically changed, but things haven't so radically changed as you suggest because of molecular phylogenetics.

Re:why is it compared to a squirrel? (1)

jd (1658) | more than 2 years ago | (#37951786)

"Saber-toothed rat" part:

Agreed completely on two grounds. Rats, even the extinct 0.75 tonne ones, are closely related to squirrels so no matter what method you use you will get about the same distance to this new species and therefore you can pick either. However, your point (I think) is that the relationship is so distant from any extant small mammals that you can still pick any of them with a roughly equal probability of picking the one that actually is the closest. I can buy that.

General Sciency part:

Morphological data is often all paleontologists have to go on (although you CAN extract spider and brewing yeast DNA from 45 million year old amber), so in such cases there simply isn't a choice. You have to go with that because there's nothing else to go by. Well, not unless you've a handy TARDIS or other time machine.

The relationship that you're talking about tells us structurally how things relate. It can be used to build up a reasonable tree showing where the relationships coming from. I say "can" because, as you know, the early family tree of birds is highly contentious due to the question of which changes are considered important and which are not. You get very different trees according to how you divide the characteristics up. A morphological tree, then, is most useful when there's no ambiguity. Ambiguity is always a warning sign that there's insufficient data leading to multiple possible scenarios.

Let's assume that we have a good tree, though. What can we infer from it, beyond where species divided off? Not as much as we'd like. We know that a morphological change is caused by a genetic change, but not all genetic changes lead to morphological changes and equal-sized genetic changes can produce unequal-sized morphological changes. As a result, having the tree gives us plenty of constraints on the relationship between two species and it gives us a specific number of parameters, but it doesn't give us values for any of them.

Specific to this Post Part:

It's extremely hard to say what is meant by "relative" in this context. If you mean "this species isn't a direct ancestor of squirrels" then I'd say you're absolutely correct. If you mean "the order to which this species belongs is not directly connected to any part of the ancestral lineage of squirrels" then I'm happy to accept that at face value. If you mean "the last common ancestor between this and squirrels pre-dates other branches from either lineage that survive today and are not considered related", again I'm happy to accept that. In other words, anything that treats the tree as a genealogical map and considers Nth cousins for some accepted value of N as being "related" and nothing else is probably going to say these species are unrelated.

From a molecular standpoint, things get more complex. In terms of the genetics, it is technically wrong to depict all morphological branches as being at equal angles from the lineage they branch from, as we simply don't know how many evolutionary steps were taken for the changes to become visible. It might be one, it might be a million. But because rock doesn't preserve DNA too well, we have no way of knowing which end of the spectrum things are. Hence, the simplest option is to assume that the average will be about the same as you can't really do otherwise.

The practical upshot is that if we take the morphological tree, some branches may be squished together and others may be much further apart than the morphology alone would suggest. So, if you define "relative" as being "within a certain distance" on the tree in a straight line rather than as a count of branchings (ie: the genetic distance falls below G, where G is some threshold for what is considered related), you can guarantee you'll get very different results than from the morphological genealogy. What you can't do is say in which direction and therefore you can't say (for fossils, at least) what the straight-line distance is and therefore cannot say how closely related something is at the molecular level. There's no formula you can use to even begin to estimate the value of one from the value of the other.

Variations in the Morphological Tree:

As noted for the case of early bird-dinosaurs, the morphological tree depends on what morphological aspects are considered important. It was a crowded environment, there were many experiments in dinosaur flight and dinosaur feathers, these experiments are morphologically very similar (convergent evolution - a bastard to work with) because flight mechanics don't change according to the aeon and there simply aren't enough transitional fossils yet to build an unambiguous tree. This doesn't, of course, mean that the different experiments were related in any way other than the way they are currently believed to have been. What it does mean is that individual fossils are getting reclassified rather more than they should be, which means that assumptions based on a specific fossil being in a specific place in a specific tree may well end up proving wrong.

In the case of new species, especially if the order isn't overly well-known, you obviously have very few transitional fossils to work with. The less well-known the order, the fewer the transitional fossils and therefore the greater the probability that the order has been incorrectly mapped. Homo Sapien Sapien is a great example, since we now know modern Homo Sapiens are, in fact, a hybrid of Homo Sapien Sapien, Homo Sapien Neanderthalis and Homo Sapien Denisovis, and possibly of Homo Sapien Florensis as well. There may be other hybridizations in there as well. However, "pure" Homo Sapien Sapien also exists today. You can't draw this as a spanning-tree, obviously, and it's not clear how you'd begin to draw it at all since we lack any of the transitional forms involved.

In any situation where the tree has been laid out, a prediction has been made on what transitional fossils might look like and where they may be, and where transitional fossils of about the right look and about the right place have indeed been found, it's safe to say that any node in the Linnean system will correspond to a specific modal type in the genetic tree even when you can't obtain the genes themselves because they don't exist. However, not all genetic branches correspond to Linnean branches and unlike genetic branches CAN map onto Linnean branches because of convergent evolution. Further, genetic branches that are close enough can hybridize even if the morphological tree says they shouldn't be able to. This does happen, which means the tree becomes more like a mutant bush in which branches can fuse together and spawn off new branches at the point of fusion. That's when the standard model doesn't just break down, it runs off crying into a corner and won't come out until you give it milk and cookies.

It's in areas like this, the fringe cases, where the tree ends up getting revised the most, although revisions happen everywhere. Again, converging evolution is a bitch and should be outlawed where genetic tests for parenthood are unavailable.

In other news (1)

jd (1658) | more than 2 years ago | (#37944602)

An extinct giant short-faced bear [] that went extinct 5 million years ago would have put up a decent fight against Secret Squirrel here. "Our analyses show that it had the most powerful bite of any known terrestrial mammal determined thus far," Dr Wroe told BBC Nature.

Re:In other news (1)

Ol Biscuitbarrel (1859702) | more than 2 years ago | (#37946500)

The North American giant short-faced bear, Arctodus simus, was actually larger, from what I've gathered, and went extinct only 11kya. Maybe it couldn't have bit through a fire hydrant but a 3.5k lb bear 6 ft high at the snout is crazy enough for me.

Re:In other news (1)

jd (1658) | more than 2 years ago | (#37950412)

Biting through fire hydrants is terrible, though. You've got to think of the dogs!

Ok, seriously, yes. I wouldn't have wanted to have met any of the ancient bears. Even the European Cave bear was lethal and psychotic. Nothing after that point matters, unless you're into making slasher horror films and want to make them biologically correct.

34th rule (0)

Anonymous Coward | more than 2 years ago | (#37944624)

So, how long will it take to become rule 34'd by furries?

Terra Nova (1)

jameskojiro (705701) | more than 2 years ago | (#37944908)

When do we get this little critter be a pet for one of the humans on the show Terra Nova, or do the idiot science advisers have no clue that mammals even existed 85 million years ago...

The forests should be chock full of little mammals scurrying about here and there.

No, they just want top show us the cool and awesome dinosaurs.

Re:Terra Nova (1)

Coren22 (1625475) | more than 2 years ago | (#37951454)

That would be because Terra Nova shows on Fox, and Fox has nothing to do with science :)

They are alive and well... (1)

Nyder (754090) | more than 2 years ago | (#37945644)

... as a mount in Everquest 2. Have to buy it off the Station Market though.

Yes, it's saber tooth and will pull out an acorn to chew on.

Not a squirrel, a FERRET! (0)

Anonymous Coward | more than 2 years ago | (#37946942)

...event though this is some ancester to mammals, it looks more like a ferret than a squirrel.

When I read about a saber toothed squirrel... (1)

Tetsujin (103070) | more than 2 years ago | (#37952048)

On reading about this thing, I can't help but imagine a squirrel yelling "BERSERKER CLAW!" as it tears some hapless creature apart.

Just that they do not look like squirrels (0)

Anonymous Coward | more than 2 years ago | (#37963526)

The look more like a bandicoot with the long pointed snout and squirrels have rounded heads

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