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Archive for the ‘Extinct’ Category

megalodon

I lived through that great Shark Week debacle in 2014, when the usually fairly reputable Discovery Channel showed this bizarre pseudo-documentary called Megalodon: The Monster Shark Lives. I believe I watched all of five minutes of this monstrosity, and I knew that the thesis posited in the film, that there really still are Megalodon sharks swimming the seas, would be taken as fact by a certain percentage of the credulous public.

If such an animal really does still live in the ocean, then small to medium-size craft could be endanger at all times, but of course, no real evidence of late surviving Megalodon has ever been produced.

Indeed, when this documentary came out, I was quite aware that some shark specialists were doubtful that these large sharks survived into the Pleistocene.

Well, we now have some really good evidence, based upon an extensive re-evaluation of the fossil record of Megalodon sharks, that the species went extinct about 3.51 million years ago. It was previously believed that the species went extinct 2.6 million years ago, and recently, a supernova was suggested as the likely culprit.

However, this new date means that the supernova probably did kill off lots of large marine mammal, but the Megalodon had already been gone for about a million years before the supernova hit.

This new study, published in PeerJ, contends that the species became extinct as the modern great white shark spread over the world from its ancestral home in the Pacific Ocean. Great whites became widespread in the world’s oceans around 4 million years ago, and their spread roughly coincides with the new extinction date for the Megalodon.

The authors contend that the juveniles of the Megalodon were unable to compete with the adult great whites, and because a species cannot exist very long if its young never survive, the great white might very well be the culprit behind the extinction of the Megalodon.

So no, Megalodon doesn’t live. Jaws took it out long ago.

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sea mink

Depending upon how one understands the red wolf, the United States has had only two native carnivoran species go extinct. One of these was the Caribbean monk seal, which was one of three species of monk seal that once swam the warmer waters of Hawaii, the Mediterranean, and Florida, the Gulf of Mexico, and the West Indies.  The Mediterranean monk seal still holds on, and I’ve laid eyes upon a few Hawaiian monk seals. But the Caribbean species is gone. Sightings still persist in redoubts throughout the West Indies, but virtually every expert believes the Caribbean monk seal to be extinct.

The second species we lost is a bit of a mystery, and yes, there is a bit of a debate as to whether it really was a species at all. The North American mink is a fur trade staple. It has been bred in captivity almost as extensively as red foxes have, and it has been accidentally introduced on more than a few occasions.

In its native range, it is quite widespread, and studies of North American mink and their predation upon muskrats were the basis of early predator-prey ecological studies.  These animals are even undergoing a sort of domestication and training as hunting animal in Utah.

But that common species of North American mink may have not been the only one on this continent. Another mink species was described along the rocky coasts of Maine and the Maritimes.  It was called the sea mink, and unfortunately, it was not described until 1903, when it was already extinct.  The trappers of Maine and the Maritimes knew the mink of the coast was somewhat different, but they had already trapped it out by 1894. The animals were described as being very large mink, measuring 36 inches in length and possessing a reddish coat.

When they were eventually described as a distinct species in 1903, much of the data backing their taxonomic status was based upon skulls taken from shell middens of the Native Americans. Their dentition was different enough for some scholars to maintain that this mink with the big teeth was indeed its own species. The current consensus is that there was a sea mink, and this consensus is made upon an another more sophisticated comparison of its dentition with other North American mink.

It should be noted that not everyone agrees with this species status based upon dentition alone. Richard Manville has long maintained that the sea mink was a unique subspecies of North American mink. Manville examined several specimens, including one that he thought was intergrade between the sea and “wood” mink form, and he concluded that the sea mink was nothing more than a subspecies.  Manville noted that purported sea mink remains dating to around 4,000 years ago were found in inland Massachusetts, well south of where the sea mink was supposed to range. Further, they were found so far from salt water, which led Manville to question whether the sea mink was so regionally distributed and so connected to the ocean as was believed.

Many comparisons have been made between the sea mink and the North American mink that live on the Alexander Archipelago of Alaska. Those contemporary mink are quite large and live very similar lives. Like the sea mink, this large Alaskan mink relies upon cold, boisterous seas for its food. Shellfish feature also prominently in its diet, and it could be argued that the two forms evolved in parallel of each other.

I am leery of modern species being described solely off of morphological characters alone. Because sea mink remains definitely do exist that could be used for DNA extraction, one wonders why no one has tried to use this method to resolve this question.

Now that this large mink is now extinct, its taxonomy is less urgent.  This larger-sized sea mink was in demand because of its coarse fur, which would have been in demand to make fur coats, and its larger size meant that fewer mink would have to be trapped to make the same size of garment. It was definitely trapped out of its range, and all that was left was that other form of mink, which the New England trappers called the “wood mink.”

If this sea mink was just a subspecies, it likely exchanged genes with the local wood mink, and there is a distinct possibility that we could find its genes in some “wood mink” living today.  Even if it were a distinct species, it is possible that the two forms didn’t lose chemical interfertility.

So maybe the US lost two species of carnivoran in historic times. Or may we’ve lost only one. Just like the species status of the red wolf, the sea mink is still contentious in the literature, but unlike the red wolf, there are no molecular studies that have attempted to resolve this problem.

And we are left wondering about the mystery of what has passed, once again.

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Not so long ago, in terms of the history of our species and certainly not long ago in the history of the world, two “cheetahs” roamed North America, probably running the pronghorn and Odocoileus deer. They were fast and svelte like that cat of Africa and Asia, but they did not make it into the present fauna guild of this continent. 

The great extinction of the megafauna eventually wiped out the dire wolf and these running cats, which were replaced by the gray wolf sweeping down out of Eurasia and from the cougar recolonizing from South America.

Humans probably saw these cats and maybe stole their kills, maybe not though. They were running cats in the era when North America was like frigid Africa, where the faunal guilds of Eurasia and South America ran long and hard into each other. That of Eurasia eventually dominated in the end, but the opossum and the North American porcupine still made it, even though they were part of that austral losing team.

And where there were scores of fake antelope running about with our swift deer, there were two species of coursing cat to put them to flight.  
Miracinonyx was their genus, and M. trumani and M. inexpectus were the two species.  Trumani was more like a cheetah, and inexpectus was more like a very svelte cougar.

For much of my life, these animals were classified as American cheetahs, and there was a whole mythos about cheetahs first evolving in North America. And yes, it’s true that the cheetah’s closest relatives that still live today are the cougar and the jaguarundi, both of which are truly cats of the Americas.

But a few enterprising researchers were able to get some ancient mitochondrial DNA from trumani, and with careful comparison, they found that trumani was most closely related to the cougar. 

So we now think that the cheetah evolved in the Old World from an ancient cougar-like ancestor, but in North America, one form of ancient cougar begat two species with cheetah-like adaptations.

We call this sort of evolution “parallel evolution” in which two descendants evolve similar characters that are not shared by the common ancestor. It is similar to convergent evolution, which is the same sort of evolution without a direct relationship, but in convergent evolution, the common ancestor is so distant that it almost isn’t worth considering, such as the common ancestor of aardvarks and anteaters.

So North America never had any kind of cheetah. What we had instead were “coursing cougars.”

A piece of me longs to have seen one in the flesh, and for a time, cryptozoologists traveled around Mexico looking for such an animal. There were always references to “onzas” in the colonial literature of Mexico, and even today, onza is the term used for a particular cat in the countryside.  Onza means cheetah in Spanish, and there was always a hope that it referred to these old coursing cougars. 

But every lead led to a jaguarundi, which looks like an oddly-colored cheetah-cougar hybrid in miniature, or to really thin specimens of the cougar species.

So the coursing cougars went the way of the Smilodon and the dire wolf and the woolly mammoth.

But when you realize what was here some 12,000 years ago, it’s hard to not to be caught in flights of fancy. Our current wildlife seem picayune by comparison, but we once had all the majesty of the beasts of Africa south of the Sahara.

We’ve lost all these animals during that great extinction, and now we are looming into another one, this one definitely caused by our own actions.

And the cheetahs of Africa hold on by a thread. Those of Asia have almost gone entirely. They exist only in a narrow range in the north of Iran.  There may not be 50 of them left.

Extinction looms. We know it, and yet we feel so paralyzed by its inevitability, we wonder if we can act, if we can change, before it is too late.

To be a running cat is become a true specialist. To be a courser in a world already full of long-distance running dogs is to flirt with near extinction all the time.

But twice this form of cat evolved and ran long and hard across three continents.

Not a bad gamble in the terms of evolution’s blind whims.

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extinct or alive

During the past few months, I’ve been watching Forrest Galante’s Extinct or Alive on Animal Planet, and I have been greatly impressed.  This show’s premise is kind of like Finding Bigfoot, but unlike that show,  there is actually a fairly good chance of finding the animal in question.

The first episode was a search for the Zanzibar leopard, an endemic subspecies of leopard that has been declared extinct for some time. Even the locals, some of whom include the leopard in their traditional religions, don’t believe they still exist.

But you know what? Galante’s team caught an image of one on a trail camera, and now there is serious talk about developing a conservation plan for this ende

This show uses lots of trail cameras and electronic animal calls, which are devices I know do work.

Two of the episodes were about cryptic wolves. One was about wolves in Newfoundland. Yes, the island, not Labrador.  That episode focused heavily on the wolf that was shot in Newfoundland back in 2012.  It may not have been the exact same subspecies of white wolf that lived in Newfoundland at the time of contact, but it clearly showed that at least one wolf had managed to cross the sea ice, just as coyotes did.

The team staked out several areas that looked promising for wolves, and they played an electronic caller. I know how frustrating waiting on a timid wild canid to respond to these calls can be, but in that episode, thermal footage of large wolf-like canids were captured.

The other episode that focused on wolves was the search for the Florida black wolf, a creature mentioned quite extensively by Bartram in his eighteenth century. The original claim was of a black panther in Florida, but Galante thought a wolf would be a more likely candidate.

The team did find a large canid track that matched a coyote’s track, but it was of exceptional large size. My guess is this track was left by a large Eastern coyote, many of which have wolf ancestry and, particularly in the Southeast, are often melanistic.

There was no discussion of red wolves on this episode, which I almost expected. I find discussions about red wolves a bit tedious, just because some of the assumptions behind their species status have been called into question.

And one issue is the red wolf paradigm has essentially removed the true wolves of the Southeast from the public discussion about wolves in North America. The wolves that lived in the Southeast were either red sable or melanistic, and melanism was such a common feature that Bartram reported not seeing a wolf of any other color in Florida.

Galante showed the image of the black wolf of Tensas, a remnant population of Southern black wolves that lived in Louisiana, that was captured by early trail camera by Tappan Gregory. These black wolves probably are the wolf component of the current hybrid red wolf, which are mostly coyote in ancestry now.

Melanism in in North America resulted from an ancient cross with a single dog that entered the wolf population, and melanism is associated with a stronger immune response. Wolves living in the humid subtropical South would have a selection for stronger immune systems to live in a place with lots of bacteria and worms.  These same factors, including the crossbreeding with domestic dogs, are likely playing a role in the spread of coyotes in the East. I have seen many images and photos of black coyotes, and virtually every single one of them is from a state in the humid subtropical South.

So though I doubt that that Galante would be able to find evidence of the original black wolf of Florida, I bet he very well could come across one of these large Southern melanistic coyotes that have both wolf and dog ancestry.

Maybe this animal is evolving in parallel to the older form with a different wolf stock at the base.

One other aspect of this show that I do enjoy is how much Galante goes out of  his way to look for other interesting animals. The season finale was about the search of the great auk in the Faroes, but he spent considerable time observing other seabird species. I happen to find puffins and guillemots quite fascinating, even if the great auk is likely lost to the ages.

Galante is an effective science communicator. His conservation message is as passionate but clear.  He is able to tell the story of the animal in question, and all the time, you’re truly hoping that one will appear on a trail camera or come coursing forth on the thermal imaging camera.

I have largely stopped watching wildlife documentaries because the quality just isn’t what they could be. I grew up watching all the old Survival Anglia nature films, and I almost expect the narrator to speak using received pronunciation, a bit of prejudice that Sir David Attenborough has made even worse for me.

I also dislike nature documentaries that are just pulpy and lack any real depth.

Extinct or Alive is a breath of fresh air. The show is truly about understanding the issues related to extinction and the concept of a Lazarus species, and it is exciting and entertaining at the same time.

So I am definitely looking forward to the next season this wonderful series. If you’re into this type of science-based natural history investigations, then I think you will be deeply impressed with Extinct or Alive.

I’ve not been this excited for a nature series since I was a teenager.

 

 

 

 

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The Men from Earth

Here’s the story of these two men:

The truth is that outside of some Amish or Mennonite sects, there probably weren’t a dozen farmers living like this in the late 80s.

But the other truth is that we’re all descended from people who lived like this. In fact, the nineteenth and twentieth centuries have been such a revolution for our species that it’s pretty staggering how far we’ve come.

West Virginia was once full of people like this, including virtually all of my ancestors. They farmed and hunted and trapped and lived close to the land. They were beings of this planet, not the alien beings that we’re rapidly becoming.

 

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dimetrodon berea

When I was in eighth grade, one of the classes we had to take was West Virginia history, which also included some of the prehistory and natural history of the state. One thing I remember learning was that our rocks were simply too old to have any dinosaur fossils in them, and I was a little bit crushed. We had plenty of trilobite and fern fossils, but we were going to have to forget about coming across a T. rex.

But then I came across a news item today that mentioned a rather old discovery in Ritchie County (just east of Parkersburg, for the geographically impaired). The news item mentioned that some tracks of a “pre-dinosaur” were found at the Hughes River Bridge in Berea, and that the rocks had been dated to the Permian, some 290 million years ago.

I looked around online for the discovery, and I came across this paper. In 1927, there was road project in Ritchie County that happened to expose these tracks, but it took until 1929 for them to wind up in the hands of specialists who were able to identify it as a Dimetrodon. The species name is now Dimetrodon berea, for the little Ritchie County town in which it was found.

For me, a Dimetrodon is actually a pretty amazing discovery. That’s because a Dimetrodon was actually more closely related to us than to any dinosaur.  Like us, this animal was a synapsid, and synapsids have a single temporal fenestra. There used to be many different lineages of synapsids, but currently only us mammals survive.

So maybe we don’t have any dinosaur fossils, but we do have these tracks of a pretty fell beast that was much closer to us than we’d like to admit.

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This is actually one of the better known Dimetrodon specimens. It’s not that hard to find replicas of the tracks for sale online.

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What was Junggarsuchus?

junggarsuchus

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