CCC: Rise of the Bear Dogs

Hey there every peoples!

How long has it been since I talked about just Central Coast fossils? Yeah, way too long. So now that i have finally gotten around to it, which one should I do? While I’m not one to let others influence my thought process, the idea for this one came from the geology field course i took this semester.

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Central Coast Critters: Emma

Hey there every peoples!

My math class is really keeping me on the ropes. But today class was canceled so i have found the time to write a post that i have been meaning to write for a very, very long time. This edition of Central Coast critters goes out to a very special gal. She is of of the biggest stars of the Central Coast you’ve never heard of. And she played a pivitol role in my quest to become a paleontologist.

It all begins in 2005. A new housing development called Merridian Hills was being built in the town of Moorpark, Ventura County. As is standard practice by California law, a paleontologist and/or archaeologist was required to monitor the site. As bulldozers and earth graders leveled the site, something caught the monitoring paleontologist’s eye. He spotted a couple patches of white and gray in the mud brown dirt in the wake of a bulldozer. He examined them and realized they were fossil bone! He marks the fossils, all 3 of them, with orange flags so the heavy equipment operators know to stay away from that spot. As he began to dig, he couldn’t believe what was turning up: the fossils turned out to be the skull, tusk, and neck vertebra of a mammoth! While the dozer had taken away 1/3 of the skull, 6 inches of tusk, and half the neck (literally half the neck. All seven vertebra were there, but each was cut in half), the fossils were still very complete! But then more of the fossil began to surface: vertebra, ribs, leg bones, arm bones, and even little toe bones. Bones of other animals were turning up as well. The paleontologist knew this was a much bigger task than he could handle. He contacted the Natural History Museum in LA for help. They weren’t interested, saying it was probably just another Colombian mammoth. They couldn’t have been more wrong.

While the paleontologist was trying to find people to help excavate a whole mammoth skeleton, he examined one of the teeth. It was a typical mammoth tooth, with the cemented ridges of enamel designed to chew grass. But something wasn’t right. In addition to the ridges, there were several bumps mixed in. And then the paleontologist realized this wasn’t a columbian mammoth. It was an older and much rarer American beast: a southern mammoth!

Excavation of the "Moorpark Mammoth"

The paleontologist managed to find a small freelance fossil company to help dig the specimen out. After she was out of the ground she was put into storage. The company had dome some prep work and microfossil screening, but little else. It seemed that this magnificent fossil was doomed to spend her days in obscurity in some random Moorpark facility. But then in 2007, two years after her great bones were pried from the earth, a miracle happened. The city board, who had come to nickname the fossil Emma, voted to donate the specimens to the Santa Barbara Museum of Natural History. The museum excepted, and against the odds Emma was given a second chance.

I had actually stumbled upon Emma by accident. In December 2007 i was visiting the museum and, as usual, drooling over the fossils in the paleontology hall. I noticed a couple display new and empty display cases. Then a few men, one of whom i recognized as Paul Collins (curator of vertebrate zoology), wheeled in a cart loaded with fossils. There was an articulated hand, an articulated lower back leg, a vertebra, and a mammoth’s characteristic molar. I made some brief chat with the museum staff wherein they explained that these fossils were found in Moorpark in 2005 and had recently been acquired by the museum. He also explained they were going to have a prep lab that summer to prepare the bones. And what do you think happened? I volunteered that summer and spent one day a week prepping not just any fossil, but a very unique one.

Boy do i look dorky!

No i didn’t dress like that every time! But overall i spent a total of 55 hours pepping a mammoth that summer. And it felt fantastic! Long before i had the tools to combat my depression, this gig gave me such a boost in confidence, self-esteem, and self worth. I was proud to tell people what i was doing. I felt like i was actually contributing to the paleontological community as well as help my favorite museum. I was even quoted in a Ventura newspaper as saying “You wait your whole life for an opportunity like this”. But all good things must end, and at summer’s end the prep lab was closed up. I tried to continue doing volunteer prep work, but Paul said they had a guy coming in once a week to do that. And ever since then, i have been trying to experience the high i had that summer. But i have failed for the most part. The sense of pride, achievement, joy, fulfillment… I was exercising my passion, living it, doing what i waited my whole life to do. All efforts to get back in the game from then on failed, only fueling the despair and darkness that plagued my being. I remembered fondly that summer and the work i did, only then weep for what i had lost.I’m better now, but my efforts to get into the paleontological community have been fleeting at best.

But back to the heart of the matter: why is Emma such a big deal? Well for starters, she’s a southern mammoth. The southern mammoth (Mammuthus meridionalis) is well known from Eurasia but is much rarer in North America. The southern mammoth is presumed to have been the first mammoth in North America, crossing over from Asia about 1.5 million years ago. I don’t know of many southern mammoth fossils found in North America, but oddly enough the ones i do know all come California. Southern mammoth fossils have been found in Victorville, Anza Borrego State Park, and Moorpark. Plus Emma has the potential to be the most complete southern mammoth in North America. The current record holder is a specimen held in the Smithsonian; a large female discovered in Anza Borrego in the 1970s, is about 70% complete. Emma could be a contender, but until an official bone count is done, we won’t know for sure.

The skull of Emma

Emma's feet and hind limb bones in a big fossil log jam!

Emma is also significant for her age. Based on an index fossil known as Meade’s Pine Mouse, the site was dated to around 750,000 years ago. A lot of fossil sites in California, especially on the coast, tend to be late Pleistocene, 40,000 to 10,000 years old. Emma’s site is from the middle Pleistocene, a less well understood time period. But the mice weren’t the only fossils found there. Fossils of the Western Horse (Equus occidentalis, though since i don’t know what was found i don’t know how concrete the identification is), llama, and mastodon (a pair of mastodon tusks were found across the road from the construction site, but i don’t know if they are from the same layer). This fossil assemblage is important because it’s another piece of the puzzle of life in the middle Pleistocene. The age of the site is roughly the same as the Fairmead Landfill, so we can make a comparison and perhaps better understand Emma’s site.

Finally, Emma is important because of where she is from. The Central Coast, as i try to show through this blog, has a surprising rich fossil history. And i have all too much lamented, much of that amazing history is locked up, out of sight, out of reach, in museum to the north and south of the Central Coast. But that such a valuable and spectacular specimen remained on the Central Coast, in a place where she will be appreciated and treasured, is a great victory indeed. Emma has come a long way as it is, to be stuffed into the echoing vaults of a larger museum would be tragic. Like most other fossils on the Central Coast, her story should be told and shared with the world. If only more fossils from the Central Coast (like the fossilized whale brains or Avila’s giant sea cow) were as lucky as Emma.

Someday, when the museum has the space, she will become the centerpiece of a revamped paleontology hall. Over the years i have sent them various ideas for such a hall. They said they appreciated them and would keep them in mind. I think i hinted in an earlier post that perhaps instead of trying to start my own museum i should help an existing one. Well I can think of no one better than the Santa Barbara Museum of Natural History. They already deal in all things Central Coast. Plus, they don’t have a paleontology curator; their small fossil collection is looked after by Paul Collins, who you can imagine is more interested in modern faunas. I recently tried to get a BLM permit to search the Caliente formation for fossils. The museum director appreciated the offer, but turned me down because they have neither the curator nor the storage space to accommodate what could be a new stream of fossils. I have always thought that if i were ever lucky enough to join up with SBMNH that the main museum could display Central Coast fossils while an offsite facility (like the Sea Center) could deal with the stuff from further abroad. It’s an unrealistic thought, much like the Grand Vision. But hey, if a rare fossil can be uncovered by a bulldozer and then remain in it’s homeland, then why can’t i join up with a kickass Central Coast museum and help them share the wonders of the ancient world with our moern one.

Till next time!

The Fossil Whale Brains of SLO County

Hey there every peoples!

A quick post today to take advantage of a piece of news while it was fresh. I came across this story in today’s edition of The Telegram Tribune, our local newspaper. It is a story about an incredible find that for me is not only heart warming but also infuriating. Let’s dive right in!

Around nine years ago, a local woman named Pepper O’Shaughnessy was wandering about her family’s property when she noticed something sticking out of a sand bank. She pulled it and had no idea what she just found. What she was holding was a 15 million year old fossilized whale brain. You read that right a fossilized whale brain. Now fossilized brains have been found before, most notably among dinosaurs. But these are usually endocasts, molds of the inside of the skull that show the rough outline of the brain. This whale brain is something else, according to Howel Thomas and Lawrence Barnes, a marine mammal experts at the Natural History Museum of Los Angeles County.

The fossil whale brain found right here in SLO County!

Dubbed the Olson specimen, the brain is very complete and detailed, so much so that it was initially thought to be brain coral. But further analysis revealed it to be an actual brain and not an invertebrate imitation. And what makes the story more incredible is that this isn’t the first whale brain found in SLO County. Back in the 1940s a partial whale brain was found near Paso Robles, on what is now the Halter Ranch. The specimen is owned by Templeton man Bob MacGillivray of Templeton. According to him, his specimen is not as complete as the Olson specimen but more detailed. And to make these fossils even more amazing is that they each represent different types of whales. The Olson specimen is from a baleen whale and the MacGillivray specimen is from a toothed whale. Alright Howel and Lawrence, lay it on us why these fossils are a big deal (from a preliminary report):

“To have two fossil whale brains from the same geographic area, from the same time period, with the same type of preservation and representing both orders of whales is simply incredible,”

While the MacGillivray specimen is on loan to the LA Museum, the Olsons have other plans for their fossil. This requires a trip back to 1998. Pepper O’Shaughnessy’s niece, Tara Olson, and her friends were coming back from a concert in Paso Robles when she fell asleep at the wheel and wrecked here car. Tara survived the accident but suffered brain damage. Doctors thought that she’d be paralyzed for life and would be wheelchair-bound for the rest of her days. But Tara fought on. She was sent to the Brucker Biofeedback Center in Miami, Florida. With sheer tenacity and attitude, she was able to get back on her feet in 3 weeks. She now walks with a cane and has some trouble speaking, but considering her original prognosis, she’s accomplished the unthinkable. Now the Olson family wants to help others with neurological troubles by opening a branch of Brucker Center on the west coast, right here in SLO County. And they plan on using their rarest of fossils to fund it. They hope to find a philanthropist to sell the fossil to. The ideal situation is to use the money to at least get the ball rolling on the neurological center and the donor would donate the fossil to a museum. While i am staunchly opposed to the sale of fossils, this plan doesn’t sound so bad, assuming it went as planned. But what museum would it go to? Alas, that is where this story really gets to me.

If it were to end up in a museum, it would probably be LA. Now i know that would be a good place for it, considering they have the staff and facilities to properly curate and research the specimen. But hear me out. You heard how incredible and important the find is, having two fossil whale brains from the same time and place (from my home of SLO County no less). Add to that the fact that a cast of a sperm whale brain was found in Los Olivos, that makes three whale brains known from the Central Coast. But if the brains went to LA (the Los Olivos specimen is there), then they will have left their “native land”, relegated to the cavernous collections of a (relatively) foreign museum.

The reason i want to start a museum here on the Central Coast is to tell the surprisingly rich story of it’s ancient past. I have come to learn that the Central Coast is full of amazing fossils but almost none are displayed anywhere and finding information on them is quite difficult to say the least.There is a fascinating story to be told here, but it’s not being told. It’s treasures, the fossils, the very words that compose this story are locked away in distant museums. These whale brains would be a great asset to a museum on the Central Coast, but chances are they go elsewhere, to be stored and eventually forgotten.

This is a saga  that i have seen paly out time and time again. Fossil whales were found on the Channel Islands, a place thought to only harbor Pleistocene mammoth bones, ended up in Los Angeles. The same goes for whale fossils found in the vicinity of Lompoc. And other items over the years. I feel the surprising abundance of fossils should be where it can be appreciated and shared, which i feel would be here on the Central Coast. Why don’t these fossils go to the Santa Barbara Museum of Natural History? It’s a local museum, it should display local fossils! Unfortunately, the museum never had a paleontology curator or an active collecting program. Their fossil collection is limited and simply pales in comparison to the collections of LA and Berkeley, where most of my beloved Central Coast fossils reside. I have toyed with the idea that rather than try to start my own museum up here, instead help the Santa Barbara Museum build their collections. Maybe even create a satellite, like the Sea Center, except devoted to paleontology. But that’s assuming they wanted any part in my lofty ambitions. From what i can gather they  seem happy doing what they are now.

I’m sure all this ranting will amount to nothing. I may have my convictions, but people won’t give a damn. I’m sure that those with the LA Museum and Berkeley will brush my thoughts off as petulant self-entitlement, that they got the fossils first and have no obligation of turning them loose to a regional institution. And they’d be right. I’m nobody. They are are world renowned institutions who run large, successful collecting programs, produce quality research, and conduct important public programs. I’m just some community college hack who sits at home whining about things beyond his control. But this simple fact, that the rich fossil history of the Central Coast is carted away and hidden from the world, and that i can’t do anything about it, is once of the biggest factors in my depression. It is perhaps the biggest source of this overwhelming sense of despair and hopelessness that i have to constantly fight. I could put on a fantastic museum with all the fossils i have learned were found hauled away from the Central Coast. The fact that i probably never could, since a significant portion of them are kept at large scale museums, is a most bitter pill to swallow. I can’t help but think it will haunt me forever.

My depression aside, this was a very interesting story. The intentions with the fossil are honorable and Tara’s story of recovery is inspiring. Hopefully these world class fossils will find a good home. I just wish it were the one i created for them…

Till next time.

Central Coast Critters: Amynodontopsis

Hey there every peoples!

My mind has a weird way of working. It jumps around to all kinds of random things. It can pull something out of nowhere, even if the most irrelevant thing with no relation brought it out. While grappling with my depression, i realized something about my little cyber rag here. I have introduced you guys to fossil animals from the Pismo, Caliente, and Monterey formations and also the tar pits. But i haven’t shown you guys an animal from the Sespe formation. So let’s fix that.

The Sespe formation is found in Ventura County around Ventura, Simi, Santa Paula, and even Ojai. Two fossil faunas are known, each from different time periods. The lower Sepse preserves animals from the middle Eocene epoch, around 42 mya. The upper Sespe preserves a fauna from the late Oligocene epoch, 29-28 mya. Our guest today hails from the older member, a time when this part of California was warm and humid (probably home to a sub-tropical forest) and about 200 miles south. He shared his world with primitive carnivores, primates, rhino-like brontotheres, extinct ungulates, turtles, snakes, and crocodiles. He is Amynodontopsis bodei.

Amynodontopsis bodei was named for a skull found in the Sespe by Chester Stock, a paleontologist from the California Institute of Technology who is perhaps most famous for his work on the fauna of the La Brea Tar Pits. Like most of my information on animals from the Sespe, all i have to go on is the stuff Chester published back in the 1930s.

Right view of the skull of Amynodontopsis bodei

What little i have been able to gather is this: Amynodontopsis is related to Amynodon more than other amynodonts. It’s skull is unusually narrow and looks a bit like a giant tapir skull but the teeth say he was all rhino. The rest of the article is just technical jargon too complicated for my patheitc brain to make heads or tails of. But, i hope i have shed a little more light on another denizen of the Central Coast.

Till next Time!

Some Further Thoughts on Arctodus

Hey there every peoples!

As you may remember from a little while ago i didn’t have the best outlook on everyone’s favorite ice age bruin Arctodus. The loss of what may have been one of the most fascinating carnivores of the Pleistocene is probably easier to bear (no pun intended) than i made it out to be. i have tried to make it clear that i have a mental illness that severely affects my outlook and disposition. However, looking back  i now realize that Arctodus may be down, but he  may not be out just yet.

A jawbone of Arctodus from Labor of Love Cave, Nevada

I talked about Arctodus being shrunk down from the giant it is often portrayed as. Well being the numb-nuts that i am, i had forgotten that the paper that stripped Arctodus of most of it’s unique characteristics actually argues that Arctodus may have been bigger than what some have argued:

According to our estimates,
the heaviest specimens of A. simus are UVP 015 from Utah and F:AM 25535 from Nebraska, with body masses calculated as ca. 957 and 863 kg, respectively (Table 3). In contrast, the smallest
specimens are LACM 122434 from Rancho La Brea and UM25611 from Kansas, with figures of ca. 317 and 388 kg, respectively (Table 3). The fact that one third of the specimens analyzed approached a ton suggests that individuals of this size were more common than previously suspected.

They go on to mention that the largest specimens come from colder climates (at least back then). This is consistent with what is observed in other mammals, in that cold climates favor larger body size. Also Arctodus appears to exhibit sexual dimorphism like modern bears, meaning that smaller specimens are most likely females. Another interesting note about the size of Arctodus comes from Riverbluff Cave in Missouri. Preserved on the walls of the cave are many parallel gouges consistent with claw marks. Based on the size and spacing of the marks they are thought to have been made by Arctodus. Another they think it’s Arctodus is that these claw marks are 12 feet up the cave wall! Finally, Eric Scott of the San Bernardino County Museum has offered to help quell my doubts by showing me an Arctodus astragalus from Murrieta and comparing it with other bears. There’s a field trip in May so I’ll try to to it then (Thanks Eric!).

And as for meat consumption… Well, the isotope analysis was performed on specimens from Alaska and hence can’t be used to generalize the species. But just like we can’t generalize from a few specimens, can we really generalize based on one paper? They have put forward the argument that Arctodus was an omnivore, but it should not be accepted as gospel truth. People argued for Arctodus being herbivorous based on anatomy, and look what happened: specimens were found that demonstrated a diet almost entirely of meat. It’s clear that Arctodus’ diet is a bit more complicated. Who knows, maybe Arctodus was an omnivore but was more carnivorous than modern bears (like, say, 30% meat 70% plants, or maybe 40%/60%). Arctodus being a primarily vegetarian animal like modern bears raises a question: if it was a generalist, why did it die out? Surely it could have adapted like it’s grizzly cousins. One of the reasons the scavenging hypothesis made sense to me was it could at least in part explain why Arctodus died out: If all the large animals that Arctodus relied on for carrion died out, then it too would die out from lack of food. Just an observation.

In short, we still have much to learn about this animal. The dearth of fossils discovered so far should make it obvious that this bear isn’t giving up it’s secrets easily. To give you an idea of how rare it’s fossils are, consider diamond Valley. Tens of thousands of fossils were found there during construction of a reservoir. Now predators make up as small part of the ecosystem, so they are less likely to be fossilized. But still, paleontologists in Diamond Valley found: a saber-toothed cat mandible and foot bone, a vertebra and pelvis of the American lion, and a cranium fragment, a foot bone, and tooth fragments of a dire wolf. What did they find of Arctodus? A single incisor! Of all the fossils found, the mighty Arctodus is represented by a single front tooth. Even in a predator trap like the La Brea Tar Pits, it’s a rare beats. Compare 30 bears to 3200 dire wolves, 2000 saber-toothed cats, and over 120 American lions. Not a whole lot to go on. I think we need to try and get a better idea of this bear’s biomechanics: how strong was it’s bite, how did move, how did its limbs function? Also i think we need to try and do isotope studies on fossils besides one found in the north. Perhaps diet may also explain why larger specimens are found in places like Utah and Nebraska. But we won’t know for sure until we focus on trying to figure this animal out rather than trying to bust popular myths.

Incisor of Arctodus from Diamond Valley, California

Till next time!

Central Coast Critters: Arctodus

Hey there every peoples!

The Pleistocene is one of my favorite time periods. Especially the late Pleistocene, the timeframe often referred to as the “ice age”.  It feels richly exotic and yet strangely familiar. It was a time when animals of today mingled with long dead beasts. No matter how many mammoth and bison and camel fossils I see, I never get tired of the ice age. And perhaps the most charismatic are the carnivores, namely the saber-toothed cats, dire wolf, and bigass lion (which may have been a giant jaguar). But one beast has been the subject of particular scrutiny and fanfare, a creature who has proved most enigmatic. This creature is Arctodus simus, the giant short-faced bear.

Now let’s get the obvious question out of the way: how do we know this animal lived on the Central Coast? I can’t say for certain, since my information on fossils from this region is very fragmented. However I can extrapolate from nearby fossil sites. Arctodus is known from the La Brea Tar Pits in Los Angeles but this is not the only tar pit locality in California. I have found a few mentions that there were tar pits in Carpentaria, just south of Santa Barbara, which yielded ice age fossils. I have been unable to find any detailed information so I can’t say with any certainty if the short-faced bear has been found there. However I do know that it is known from the McKittrick tar pits in western Kern County. Since Arctodus is known from localities around the Central Coast, it’s not unreasonable to think it lived here as well.

 

Jawbone of Arctodus simus from the McKittrick tar pits, displayed at the California Living Museum

Arctodus has been the subject of much debate in recent times. It has often been thought of as a giant, ravenous predator that terrorized the megafauna of ice age America. But this idea, it seems, has largely been rejected. It’s almost like a reversal of what happened with Tyrannosaurus rex. People didn’t take kindly to T. rex being thought of as a scavenger, so they set out to prove it was a hunter. Arctodus suffered the opposite: people apparently had issues with it being portrayed as a hunter and set out to “cork its fangs” (to use The Lord Geekington’s lingo). But just how did this come to pass? Let’s take a look.

When Arctodus was first discovered, it stood out from other bears. While scientists were able to learn that it is related to the modern spectacled bear, this animal was very different. It was huge, larger than even the polar bears found to be roaming the Arctic. It has a short muzzle and stout canines, and it walked about on long lanky limbs. It ranged from coast to coast and from Alaska to Mexico. It’s short face and long legs were seen as convergent with felids and so it was envisioned as a pursuit predator using speed combined with its great strength to tackle bison and other large prey. As you can imagine, such an image stuck in the popular imagination, as exemplified in Kirk Johnson’s “Cruising the Fossil Freeway”:

Standing nearly six feet at the shoulders when on all fours, this 1,400-pound bruin was a long-legged killing machine that would make a grizzly look like a sissy. Given the size of their limbs and the nature of the Late Pleistocene landscape, short-faced bears were probably open-ground predators that chased, caught, and ate bison and horses. A bear that can run down a horse on an open field is a scary concept.

 

Skeleton of Arctodus simus at the La Brea Tar Pits, California

But this image was not to last.  Scientists began to take a second look at the “predatory uber bear”. Chief among them was a scientist at the University of Alaska Fairbanks, Dr. Paul Matheus. He performed an isotope analysis on an ancient Alaskan Arctodus bone and found that its diet was almost exclusively carnivorous. But this didn’t prove it was a predator, only that it was a meat eater. Matheus looked at the morphology of the bear’s legs and found that while they were good at supporting its weight, it lacked the joint dynamics and structural integrity to maintain a chase. In shorter words, while capable of impressive bursts of speed, Arctodus’ legs could break if it tried to turn too sharply due to its immense weight. Since herbivores employ a zig-zag pattern to escape, being unable to make sharp turns is a big problem for a predator. Matheus concluded that the bear’s long lanky limbs instead allowed it to move in a pacing gate, which is a very efficient way to get around. Matheus began to imagine Arctodus instead as a superb scavenger. Using highly efficient movement and a strong sense of smell, Arctodus could roam the countryside in search of carrion. But could Arctodus have survived on dead animals alone, something unheard off outside of soaring birds? Well maybe it did. Modern grizzlies are known to pirate wolf kills. But there were more than just wolves in Pleistocene America: saber-toothed cats, scimitar-toothed cats, giant lions (or jaguars), dire wolves, jaguars, and cheetah-like cats. Arctodus, Matheus argued, could have used its size and strength to scare any of these animals off their kills. And what if there was little left at the ice age dinner table? Matheus looked to the bear’s short skull and flat teeth. Shortening the skull allows for a stronger bite while flat teeth are ideal for crushing. What had been used as evidence for predation (a shortened skull) was now envisioned as a trait that allowed Arctodus to break open bones to access the highly nutritious marrow inside. Arctodus, he argued, was not a super predator but a super scavenger. And to be honest, I was hooked.

In a bizarre twist of fate, I was more fascinated by the concept of this animal as a giant trash picker than as an insatiable terror. To my feeble mind Matheus’ arguments made sense: being unable to pursue prey, this bear was well equipped to search the land for carrion and there were plenty of predators to facilitate carcass theft. To me, this scavenging hypothesis made Arctodus unique not just among bears but among carnivores in general. No other large carnivores could be perceived as subsisting on dead meat alone. But again, things made sense to my naïve thinking: it couldn’t catch prey because it couldn’t turn well (speed may not be essential to predators, but maneuverability sure is). Because this animal had flat teeth ideal for crushing and grinding (instead of the pointed teeth of T. rex) and also because there were plenty of other animals to fill the predator role, Arctodus seemed like a shoe in for the role no one thought possible: that of a super scavenger. This hypothesis even affected (or infected, I’ll let you decide) my way of looking at things. A couple years ago Alton mentioned that a paper presented by Blaine Schubert at the Society for Vertebrate Paleontology meeting discussed a study of changes in tooth shape and body size changes in Arctodus over time. As time went on, Arctodus got bigger and the anterior grinding teeth got relatively larger, suggesting a change in diet. I had suggested (naively, it now appears) that this increase in tooth size may have been an adaptation for breaking open bones. And recently I thought about another way of looking at the scavenging bear idea: damage on herbivore bones.

To the extent of my knowledge there are at least four instances where Arctodus may have been dining on the remains of the dead: A southern mammoth skeleton from Anza Borrego in California, a Columbian mammoth skeleton from Huntington Reservoir in Utah, a mammoth heel bone from Saltville in Virginia, and a mastodon femur from Kentucky (there may be more, but this is all I have read about). This may not seem like much but I’m going to go out on a limb here and compare it with bone pathologies of another kind: battle damage in Native Americans. In the cultural anthropology class I took over a year ago, we were given an article titled “Prehistory of Warfare”, which talked about warfare in stone-age societies. We can often tell if a person died in war by tell tale marks on their skeleton: fractures and crushed bone indicate clubs; narrow grooves were most likely caused by axes; and scratches in odd places, as well as embedded points, demonstrate death by arrows. Now interestingly, the highest incidence of war related death as indicated by skeletal evidence comes from California. While California is often thought of as a hippie paradise, as much as 30% of male remains from the first centuries A.D. had wounds and death blows resulting from violent attacks. It is also noted that half that number of women from the same period show similar injuries. The article goes on to say that “When we remember that not all warfare deaths leave skeletal evidence, this is a staggering number”. My point? Museum displays and classroom lectures alike talk about how unlikely it is for a bone to become fossilized. I think what could be done is look at all bones thought to have carnivore trauma and try to determine who made what. A high amount of damage attributed to Arctodus could indicate a high amount of scavenging. And like the ancient wounds, not all scavenging would leave traces behind on the bones. And when you consider all the bones that wouldn’t have made it into the fossil record, this could indicate Arctodus was doing a buttload of dumpster-diving. What’s also interesting to note is all the instances of inferred scavenging are bones from proboscideans, the biggest animals on the landscape. Now I don’t know if scavenging evidence on the Huntington Reservoir mammoth comes from tooth marks or the fact that a couple Arctodus bones were found alongside it. Though it’s presence at the site of a mammoth carcass may be some indication: Arctodus fossils have also been found alongside mammoths at Hot Springs, South Dakota and at Saltville, Virginia. But seeing as how paleontology is reliant on hard evidence, this entire paragraph is just stupid meaningless speculation on my part.

I have rambled on at length about how fascinating the idea of Arctodus was a scavenger is, but it is all for naught. The giant, short-faced bear that ran around on long legs trolling for flesh apparently never existed. Recent studies have shown that everything that ever made Arctodus unique have all been faulty observations. First off, it wasn’t a giant. The bear’s odd proportions have made it difficult to pin down its size but the consensus now appears to be that the figures of 1800 pounds or more are unfounded. “Fossil Treasures of the Anza-Borrego Desert” notes that studies by a fellow named Kurten used full body length to estimate that females weighed between 550 and 614 pounds while males weighed in around 770-825 pounds. His femoral cross-section analysis put females at around 594-638 pounds. Even though it cites a specimen from Utah weighing about 1364-1452 pounds, it is noted that this is a particularly large individual. It has been argued that because Arctodus was lanky it was not as massive as other bears; therefore the estimates of one ton are erroneous. Many think now that Arctodus rarely exceeded 1200 pounds in males, making it no larger than a brown bear. But the “fang corkers” were just getting warmed up.

 

A comparison between the "giant" short faced bear and a modern polar (image by and courtesy of Daniel Reed)

A paper released a year ago really went to town on the short-faced bear. They found that it didn’t have as long a set of legs as people originally thought. They argued that it wasn’t proportionally different than other bears and that the long legs are something of an optical illusion caused by its short back (Brian Switek notes that modern bear skeletons do look a big leggy themselves). Given this new information, the arguments that its long legs allowed it to run down prey or cover vast tracks of land were now irrelevant. The researchers also found that it wasn’t a short-faced bear either. Again, when compared to other bears and other carnivores, Arctodus’ skull was proportionally no different. This too may be an optical illusion caused by its deep skull. And diet? They suggest that Arctodus best be viewed as an omnivore who occasional ate meat like modern brown bears. But what about those isotope studies that showed it almost exclusively ate meat? The authors contend that the specimens used are all from Alaska and thus only demonstrate that that particular population ate meat and thus should not be used to generalize an entire species roaming a continent full of different environments (Alaska is often portrayed as a steppe environment. Perhaps the Arctodus up there had to rely more on meat because suitable plant food was not available). Arctodus, the once mighty king of the ice age, was reduced to a run of the mill ursid.

I know this sounds pessimistic (did I mention I suffer a mental illness ?), but what is so special about Arctodus now? Everything that ever made it unique: size, long legs, a short face, a carnivorous diet (whether through active predation or scavenging), has all been shown to be false. Pretty much it becomes like any other bear. I mean, I get excited over bison or horse fossils, which are no different from their modern relatives. But they are special at least because they are found in places they no longer live in. To have an animal usually associated with far away exotic locations found right here makes them unique. But when it comes to Arctodus… so what? We still have bears in North America. Hell we have three species of bears. And it’s possible existence on the Central Coast wouldn’t too much of a boost either, seeing as we had the equally big and ecologically similar grizzly bear roaming the place in historic times (it’s how the town of Los Osos got its name. Its full name, Canada de Los Osos, means “valley of the bears”). It seems Arctodus’ only claim to fame now is that it’s an extinct bear and we got its biology and ecology horribly wrong. Had its fangs corked? I’d say it’s effectively been castrated.

 

Arctodus has come full circle ( from the new paper)

They say that the bigger they are the harder they fall. And Arctodus sure has fallen hard. It went from uber bear to ultimate scavenger to just another bear. Whereas T. rex survived its fang corking, Arctodus was knocked off his pedestal for good. But this is the way science works. It’s not about what you want to believe… it’s about what the evidence says. And the evidence says that Arctodus wasn’t all that different from other bears. I know I will probably get flak for not being able to still appreciate it. I still do, but for reasons I don’t understand, Arctodus has lost most of its grandeur and wonder. I will still enjoy seeing its fossils in my museum hopping, but I can’t help but feel like the ice age has lost one of its most fascinating aspects.

Till next time!

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Addendum: i have written a follow up post

Central Coast Critters: Osteodontornis

Hey there everypeoples!

I had originally reserved this post for a very special gal, but given the recent buzz about the new species of Pelagornis I thought I’d give the slot to one of the more bizarre denizens of the Central Coast.

A long time in a quarry outside Santa Maria, workers found the skeleton of a strange creature. It looked like a bird, but was far bigger than any bird that plies the coast today. That and it looked like this thing had teeth! So the specimen was taken to the Santa Barbara Museum of Natural History where it can still be seen today. The creature was identified as a new type of sea bird by then curator of Anthropology Phil Orr (he also dabbled in paleontology). It was thus named Osteodontorniss orri, the giant “bone-toothed bird”.

Part (original fossil) of Osteondornis orri at the Santa Barbara Museum of Natural History

Counterpart (mirrior imprint of fossil) of Osteodonornis

This bird had a wingspan of 14 feet and would have stood over 3 feet tall. Given the size and shape of the wings, it is likely that Osteodontornis flew like a modern albatross, using long slender wings to soar over long distances in search of food. But being a bird it would still need to come to shore to roost and breed.  Osteodontornis would have picked off fish and squid that strayed too close to the surface. And that’s where the bird’s namesake comes in. The bird’s name derives from several tooth-like structures in the beak that would have proved very useful for snagging slippery prey. But these structures were actually bony extensions of the jawbone rather than true teeth. Nonetheless it probably made it look like dinosaurs had come back to life!

Osteodontornis may have been found here first but he has been found further afield. The bird appears to have occupied both sides of the North Pacific. Many fragmentary specimens have been found at Sharktooth Hill in Kern County. A couple fossils have been found across the ocean in Japan. Also an obscure bone was found on Vancouver Island. It is an abraded part of the tarsometatarsus found in what is thought to be the Eocene-Oligocene boundary. This would make it much older that Osteodontornis (indeed the bone has been given its own genus: Cyphornis). Many think the rocks in which the bone was found may actually be early Miocene in age, which would mean this could be an early species of Osteodontornis. But other pseudotooth bird bones from Oregon that date from the Eocene-Oligocene boundary are thought to possibly be from the same animal. This is possible, if the rocks in Vancouver are in fact that old. But being bird bones, they are hollow, thin walled, and very fragile. The few bits that do survive don’t offer much information on who is who.

Osteodontornis jaw fragments from Sharktooth Hill, Kern County

And this fragmentary nature makes it difficult to discern which bird group Osteodontornis and his kin are related to. While we are able to group pseudotooth birds together (Pelagornithidae), their broader relationships are harder to be certain of. At first they were grouped with the Pelecaniformes, which includes pelicans and gannets. But a later study found that they may be more closely related to waterfowl. The pseudotooth birds’ relationships to other birds may be difficult to ascertain since we have trouble just trying to figure out how many species and genera of pseudotooth birds there actually is. As noted above, their fossils are rarely preserved beyond partial bones.

All that aside Osteodontornis is the biggest seabird ever to call the Central Coast its home. It must have been even more spectacular in flight than the pelicans I see at the beach. While you can get up close and personal with the original specimen, the closest people can get to seeing the splendor of this great bird is a life size cutout above the skeleton. I had once suggested to the Santa Barbara Museum that when the day comes to renovate their paleontology hall (and trust me, it really needs it), they should try to recapture this ancient bird’s glory. I suggested having a reconstructed skeleton (or better yet a fleshed out model) perched on a rocky outcrop with its wings outspread is if it’s preparing for takeoff. The original specimen would be mounted inside the wall of the outcrop. Whether this will be or not is uncertain. The museum turns 100 in 2016 and has accordingly plotted out a master plan to revive the museum for its centennial. I hope my suggestions to the museum at least inspire ideas about what to do. And frankly, if they only listen to one of them, I hope it is my idea for Osteodontornis. He’s been at that museum for a long time. It is only fitting that he gets a grand re-envisioning.

Osteodontornis soaring over the shores of Miocene California (crappy image due to it being scanned in from an archaic 1960's field guide)

Till next time!

Addendum: The Coastal Paleontologist informs me that recent study has shown that there is insufficient evidence for differentiating between pelfronids. As such, Osteodontornis orri is now Pleagornis orri.