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Posts Tagged ‘dire wolf’

dire wolf mesomelas

It was always assumed that the dire wolf and its kin, the endemic extinct North American wolves, were very closely related to modern wolves.

However, the genome of the dire wolf was just sequenced by a team of independent researchers at the Russian Institute of Cytology in Saint Petersburg.  The team of geneticists and paleontologists was led by Boris Yudin. The team wanted to have access to the remains of dire wolves at Rancho La Brea, but they were instead able to obtain access to several skeletons that were being held at the Indiana Museum of Natural History.

“It was very hard to get access to the specimens,” says Yudin,  who has always been fascinated by Pleistocene North American megafauna, “But once we did get access, the DNA sequences were quite easily obtained from the shoulder bones.”

“We were able to get one full genome sequenced, and then we began to compare this genome with other species in the genus Canis,”  says Yudin, “and using a Bayesian analysis, we were quite shocked to learn that the dire wolf wasn’t really a wolf at all.”

Most paleontologists had believed that the dire wolf was a sister species to the modern gray wolf, and if this assumption were true,  the dire wolf genome would be most similar to this species.

However, the dire wolf didn’t share an affinity with the gray wolf. Instead, it shared a much stronger relationship with the black-backed jackal, a species of canid found in East and Southern Africa, which is quite genetically distant from other wolves and jackals.

“There is even a debate as to whether the black-backed jackal even properly belongs in Canis,” says Yudin, “It is so genetically divergent.  But our research found that the dire wolf and the black-backed jackal are sister tax.”

Using the genetic differences between the dire wolf and the black-backed jackal to calculate when they last shared a common ancestor,  Yudin’s team estimated that the two species split only about a million years ago. Black-backed jackals and their current living closest relative, the side-striped jackal, are believed to have diverged from the rest of Canis some 5 million years ago, and the same is true of the dire wolf.

“The two divergent African jackals and the dire wolf form a clade, and if we are to classify the  two jackals outside of Canis, then the same will have to be done with the dire wolf,” Yudin points out.

“Within the dog family, the tendency towards parallel and convergent evolution cannot be underestimated.  We now know there are jackals and wolves that exist now and have existed that come out of divergent lineages. This is the most important discovery,” says Yudin.

So now we have the golden wolf of Africa, which is a convergent form of jackal out of the wolf lineage, and we have the extinct dire wolf, which was a divergent jackal that evolved into a wolf.

Yudin’s team plans on extracting the genome of the Armbruster’s wolf, which is conventionally believed to have been the direct ancestor of the dire wolf.  If this is true, then the Armbruster’s wolf will also share an affinity with the black-backed jackal.  The team also is beginning an analysis of Pleistocene coyote genomes from across the United States.

“It is an amazing time, ” says Yudin. “Many discoveries to be made.”

Disclaimer:  Please do not post this story as authoritative until reading this post that acts as a follow-up. 

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dire-wolf-baculum

Dire wolves are one of those creatures from the past that has captured the public imagination. They are conventionally dreamed of as being massive wolves, and Hollywood has created fictional ones the size of horses.

The truth of the matter is they were only slightly larger than the largest of modern North American wolves.

We know that they were closely related to modern wolves, but their exact position in the wolf family tree is still a bit contested.  The two species are close enough in appearance that it often takes a specialist to figure out whether one is looking at the skeletal remains dire or modern wolf the measurement of the skull features and limb proportions.

One feature, though, that is diagnostic of the dire wolf is its  robust and “perky” baculum.

If you don’t know what a baculum is, that’s because you’re human. In virtually ever other species, the males have a “penis bone” or os penis.  Where I grew up in West Virginia, it was not unusual for men to wear a raccoon’s baculum as talisman of both one’s virility and redneck bona fides.

The dire wolf is one of those ancient animals for which we have a lot of skeletal remains to examine.  In the famous La Brea Tar Pits, where the remains of over a million Pleistocene creatures have been found, dire wolves are the most common species to have been recovered.

The tar pits were a death trap for all sort of large herbivorous mammals, and when they became stuck in the natural asphalt tar, they were easy pickings for scavengers.  Dire wolves came to the tar pits to eat, but many, many of them died. Over 200,000 of them have been taken out of the site.

With such a big sample of dire wolf skeletal remains, paleontologists have been able to figure out quite a bit about their growth patterns, but of particular interest are the bacula of the male dire wolves.  They are shaped not the bacula of any extant canid. They are curved and robust, and when compared to modern wolves of the roughly the same size, they are 44 percent longer.

That is a unusual find, and it suggests something about dire wolf behavior that isn’t true of modern wolves.

Modern wolves generally reproduce through a mated pair. In most wolf packs living in most situations in the wild, only a single pair in a pack gets to mate and produce pups. Other wolves in the pack might mate, but their pups will either be killed or abandoned.

This doesn’t happen every time. If there is abundant prey, these young females are sometimes allowed to raise their pups alongside their mother’s litter.

But in most cases, they don’t get to raise pups.

Modern wolves spend a lot of energy making sure that the mated pair, who are usually parents of the other wolves in the pack, get to mate and get to mate with each other.  The other females in the pack might become pregnant, but they will be attacked if they try to mate with the main breeding male.  The only way they ever get pregnant is by wandering interlopers who haven’t yet formed a pair bond with a female.

During the mating season is when young wolves typically leave their parents’ pack.  They typically don’t have any mating opportunities, and the constant bickering wears on them.

The big and strangely shaped bacula of dire wolves suggests they might not have been quite like modern wolves.  These bacula are suggestive that dire wolves were “better endowed” than modern wolves, and larger genitalia is usually associated with a less physically competitive reproductive strategy.

This phenomenon is well-known in primates. Generally, if a monkey or ape has bigger testes or penis, there is going to be less physical confrontation when it comes to mating.

The competition for well-endowed monkeys is how much semen a male can produce and how far up in the female he can penetrate it. If you can produce more semen and get it deeper into the female’s reproductive tract, then you’re more likely to pass on your genes.

In less-endowed species, there is much more physical confrontation to get one’s genes passed on.

My guess is that this applied to dire wolves. They may not have even had a proper pair-bonding system, and a dire wolf bitch may have mated with many partners in much the same way female domestic dogs do.  The male dire wolves may have had very little competition for mating. They just mated and got along with each other.

It would have been an asset in a dire wolf pack for males to have gotten along with each other. More peace in a dire wolf pack means that more wolves remain in the pack for a longer period of time, and that means they would have had larger packs that would have been much more capable at hunting large prey. They also would have been better able to run off short-faced bears from their kills and to compete with Smilodons and American lions.

It’s likely that the intense competition between huge carnivorans during the dire wolf’s reign forced them into a more cooperative breeding and pack structure.

Again, no scientist has ever seen a dire wolf or observed their pack behavior, but they had this weird adaptation that sort of points to a more peaceful pack existence than exists in the modern species.

My guess is that dire wolves traveled in massive swarms, much like those seen in dholes of today. They were ruthless scavengers and dogged hunters.

When mating tame came, they bred like village dogs. Males would bunch up around a bitch in heat and each would mate with her. There would be no pair bond between the male and female.

The competition was in the semen and the implantation thereof.

 

 

 

 

 

 

 

 

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brush wolf

It cannot be overstated how much the discovery that coyotes are not as distantly related to wolves as we believed ultimately questions our entire understanding of the evolution of the Canis species.

The traditional understanding Canis species evolved from some form of Eucyon dog some six million years ago. Wang and Tedford, who wrote the most important book on the paleontology of the dog family, believe this was Eucyon davisi, which was the first of its genus to enter Eurasia. The genus Eucyon is where the common ancestor of the Canis dogs (including Lycaon and Cuon) and the South American wild dogs would be located. Eucyon dogs were small. Imagine them as being something like a black-backed jackal or a Hoary fox rather than a coyote.

Then, 5 million years later in the Southwestern US and northern Mexico, a coyote-like Canis evolved, which was called Canis lepophagus. This animal is sometimes considered the common ancestor of wolves and coyotes. It may be, but considering how close we now know wolves and coyotes are now, it’s not the most recent common ancestor. Canis lepophagus did migrate into Eurasia, where it either founded or is identical to Canis arnensis.

In Eurasia, several smaller jackal-to-coyote forms evolved. One of these was Canis estruscus,  which then evolved into Canis mosbachensis (which is called Canis variabilis in China).

Ron Nowak believed the red wolf was an offshoot of this wolf that wound up colonizing North America and then becoming isolated from the rest of Canis mobachensis when the ice sheets expanded. There was also a competing view that the red wolf was actually a remnant version of Canis edwardii or Canis priscolatrans (which were probably the same animal). This animal was roughly the size of a red wolf, but Nowak rejected it as a red wolf ancestor because it lived too early for what he thought were red wolf fossils.

The Eurasian wolf species evolved mosbachensis-variabilis, but the two forms of wolf shared habitat and likely exchanged genes, making it very difficult

The coyote’s evolution was never clear. It was thought to have evolved out of Canis lepophagus. It was thought that lepophagus evolved into edwardii, and then it began to become more gracile and smaller, eventually becoming the now coyote.  It’s now pretty clear that it evolved out of the Eurasian Canis lupus and not these endemic North American “wolves.”

It either evolved from the modern wolf, which evolved into roughly its current form 800,000 years ago, or it came from a late surviving mosbachensis-type wolves that were regularly crossing with modern wolves before they came into this continent. Maybe the remains that Nowak had been considering “red wolves,” were actually these ancestral wolves that were evolving into the modern coyote.

Maybe when this wave of wolves came back across from Eurasia, perhaps 50,000-100,000 years ago, it came into a world already dominated by a dire wolves, which already occupied the niche for large, pack hunting canids and this wave of Canis lupus evolved as the American jackal.  After all, the bobcat is just a diminutive Eurasian lynx that found itself in a very similar position when it came into this continent, and it evolved to be a smaller animal that generally hunts smaller quarry than its larger ancestor. Of course, the modern bobcat didn’t reach its current form until about 20,000 years ago, but it still was forced to adapt to a slightly different niche than its Eurasian ancestor.

In literature on the paleontology of Canis, there is a heated debate as to how these animals all fit. The conventional view is that the wolf evolved from Canis mosbachensis/variabilis through Canis etruscus, which may be the same thing as Canis edwardii/ Canis priscolatrans. Wang and Tedford contend that the coyote and wolf split from Eucyon.  The modern wolf evolved from Canis chihliensis, which was a large wolf-like canid. It spread into North America to found Canis armbrusteri, which then evolved into the dire wolf (Canis dirus) in North America and Canis gezi and Canis nehringi in South America.  In the Old World, another offshoot of chihliensis gave rise to Canis falconeri, which the supposedly gave rise to the Xencyon, which is supposed ancestor of the dhole and African wild dog. Another view holds that the Armbruster’s wolf (C armbrusteri) is descended from edwardii/priscolatrans (which may be the same as etruscus). This lineage then gave rise to the dire wolf and the two sister species in South America, thus descending solely from North America wolves.

All of these ideas come from paleontology, and they pretty much are done without looking very deeply into the studies that are examining the DNA of these species. It is pretty obvious from that literature that the notion that coyotes and wolves split at the time of the Eucyon ancestor is quite wrong. For that hypothesis to work, African of  wild dogs and dholes would have to be genetically closer to wolves than coyotes and golden jackals are. They aren’t.

But if the genome-wide analysis shows that coyotes are so much more closely related to wolves is true, then all these fossil and subfossil canids that are said to be the most recent common ancestor of wolves and coyotes simply aren’t.  Instead, all of these species that are classified in Canis are likely a mix of evolutionary dead ends, like the dire and Armbruster’s wolf, or could be hidden ancestors of extant canids that aren’t wolves or coyotes.

For example, black-backed and side-striped jackals diverged from the rest of Canis and its allies at about the same time that Eucyon was diverging from Canis. It is possible that there are many relatives of these particular dogs that are hidden in this vast sea of Canis fossils.

The new discovery about the coyote’s split from the wolf also means that any remains of North American canid that are listed as coyote that date to 1 million years before present are not coyotes. What they actually were is a very good question.

We’ve spent a lot of time assuming that coyotes and wolves were quite divergent. We know now that they really aren’t, but when we look into the past at all the “wolves” and “coyotes” that came before, we see how this genus became so successful. It can easily evolve into big game-hunting forms, but the real success is in its ability to assume the size and shape of the generalist predator. Phenotypic plasticity is a wonderful thing for a lineage to possess.

But the real message of the new discovery about wolves and coyotes should be is a cautionary tale about paleontology. Paleontology is a wonderful science, and it makes amazing discoveries every day, but when its faced with a lineage of animals where phenotypic plasticity and tendencies toward parallel and convergent evolution are commonplace, it is bound to make errors. Paleontologists aren’t examining flesh and blood that can have its molecules tested for relationships. They are measuring anatomical characters and determining phylogenetic relationships based upon the similarities of these characters.

Which works well.

Until you get something like wolves and coyotes, where there are many ancient fossil and subfossil remains that look like they could be ancestors of either.

But the DNA says they aren’t.

And paleontology would have problem catching the inverse. There are many species that we’ve discovered only through DNA testing. African butterfly fish in the Congo and Niger basins look identical to each other, but they have been isolated from each other for 57 million years. I have yet to see this species split into two, but if they were mammals, you could bet they would be placed in distinct species in heartbeat.

Paleontology is missing some really important things we’ve since found out through molecular analyses.

And paleontologists know this.

They are working with the data they have, and by definition, it’s going to be more incomplete than genetic studies.

Science is provisional. Different disciplines and methodologies are going to come up with different answers. It’s pretty amazing that one genome-wide assay study can wipe out so much literature in paleontology.

These debates have been raging for years.

And it turns out that everyone was actually wrong.

Update 21 August 2016:  It turns out that I missed a paper that actually did some limited DNA analysis and found that Canis nehringi was pretty much a South American dire wolf, as in it was likely the same species as the North American dire wolf. Canis gezi, however, was  more closely related to the modern maned wolf and had been incorrectly identified as a wolf. So let this stand as a correction to the error above.

 

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The description of the paper comes from Facebook via Jess Ruffner:

Jeff Saunders has been looking at canids from Clovis sites. He presented results of his work on sites in southern Arizona at the Plains Anthropological Conference in October. He noted the presence of a diminutive form of Dire Wolf in these assemblages. Could this be evidence of early dog domestication in North America? We’ll be exploring this topic in more detail over the next few months. Stay tuned.

I don’t have a copy of the paper, but if I can see a copy, I’d be very grateful.

But am I surpised?

Heck no!

I’ve already discussed the possibility of the Hare Indian dog being a domesticated coyote, and there were lots of domestication attempts with wild dog species.

Only the Eurasian domestication experience with Canis lupus, the Holarctic wolf, ever actually amounted to much.

If these animals are dire wolves, then I have always had some questions about dire wolves.

Were they actually a unique species or were they nothing more than an early wolf subspecies that evolved to be really robust? And exactly how are they related to modern wolves and domestic dogs?

Most early wolf subspecies were not particularly robust, but they later did evolve into big hulking things, including a subspecies that lived in Alaksa during the Pleistocene. This wolf subspecies, though clearly within Canis lupus, but it was more robust and had very powerful jaws that were designed for hunting very large prey. These are the exact same adaptations that the dire wolf, which lived from the Central US to Northern South America, possessed– and for exactly the same purpose.

I also wonder if dire wolves became extinct entirely or if they contributed genes to modern wolves, dogs, and coyotes. If they contributed to Native American dogs, then they are likely lost, but if they contributed to wolves or coyotes, they could still have some traces of their dire wolf ancestry. I am assuming, as is most likely from observing their modern relatives, that dire wolves were fully fertile with both Canis lupus and Canis latrans.

I have not seen any comparative studies of dire wolf dna of any sort with those of modern members of the genus Canis.  Most studies on dire wolf taxonomy glean their analysis from comparative morphology– which is quite a dubious undertaking when we’re dealing with the dog family (see the red wolf debacle!)

So there are these questions.

And the fact that we have some evidence that Clovis people domesticated dire wolves is certainly intriguing.

***

The animal featured in the image above isn’t a domesticated dire wolf.

No.

It’s actually a recreated dire wolf, which is the American Alsatian breed.

Derived from mostly German shepherd stock, its breeders have tried to turn it into something like a dire wolf in phenotype.

 

 

 

 

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Source.

This post is a hoax.

Do not quote it as fact.

It is nothing more than an April Fools’ Day hoax.

The only part of it that is true is that my great great grandparents’ homestead is on Lower Run. There is a hunt club nearby, but it is on the Calhoun County side.

I hope there is no Ken Olsen who works for the US Geological Survey, because the one in my post was entirely fictitious. His name comes the late Stanley Olsen, who was an expert on ancient dog remains that were found in archeological digs, and then I played around with Stanley to get Stan and finally Ken.  If it had existed, I am sure Stanley Olsen would have loved to have examined that dire wolf skeleton. But that’s as far as the resemblance goes.

Dire wolves went extinct in the great extinction that happened in North America about 12,000 years ago.  It is unlikely that anyone will find one younger than10,000 years old.

I deleted a comment by Lane Batot yesterday, mainly because I wanted to see how many people would fall for the post.

(Please forgive me. I am juvenile.)

Lane was interested in exactly what a dire wolf was, and if we had a good DNA sample, we could figure out where these animals fit in the genus Canis. Lane was interested in knowing if it might be possible that dire wolf genes could be in modern North American wolves.

Good question!

I’m going to some posts on the evolution of Canis in the next few days.

***

I hope you can forgive me for my antics. I’m from West Virginia, and April 1 is taken very seriously here.

And I am not the only person who has engaged in these sorts of internet hoaxes.

My favorite hoax is the one on Minnesota bull sharks. It is the gold standard in these April Fools’ pranks.

However, it is not the only good one.

Last year, the Carolina parakeet was rediscovered.

Now, these things aren’t that hard to write.

It just takes a bit of pseudo-knowledge and a bit of imagination to write a piece of Grade A bull-plop.

So if you see something fantastic on this blog on April 1 again, it may not be true.

Remember, I am not without a sense of humor. I hope that you don’t get too angry with me over this revelation.

***

This is the supposed range map for the dire wolf. West Virginia wasn’t part of its range:

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Source

My, what big teeth you have!

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I don’t use the term “gray wolf,” simpy because it’s a confusing term– all of them are not gray. I use the term “modern wolf.”  Somewhat controversially,  I also consider the “red wolf” to be a subspecies of the modern wolf.  (This is why.)

But here goes:

Source

From this same documentary, I got another good video, which can be seen on this post.

That documentary was one of the better wolf documentaries, and the best I’ve seen on Canis dirus.


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