[x]

deviantART

 

©2007-2009 ~Dantheman9758
Details
Submitted: April 22, 2007
File Size: 667 KB
Image Size: 330 KB
Resolution: 1280×661
Comments: 20
Favourites & Collections: 13 [who?]

Views
Total: 3,410
Today: 0

Downloads
Total: 0
Today: 0

Embed


Thumb

Artist's Comments

Okay, so I'm a little tired of reading all the ice-age articles that like to lay claim that "Arctodus simus was the largest bear of all time!" (nearly every article I've read that pertains to this bear, claims this!) So why am I tired of reading it? Because I'm almost positive that that claim is wrong, here is why....

I at first took in that scientific information without question because I'm not a scientist, I'm just a simple artist... so what do I know about this kinda stuff.

Than I started making a large poster that documented every single animal that lived in North America 13,000 years ago, and they were all shown to scale, next to each other (over 100 species). The problem was, I couldn't get that damn Arctodus to look 500 lbs heavier than my 1500 lb polar bear. Arctodus simus yukonensis (the same reference specimen I used to make my arctodus) supposidly tipped the scales at 2,000 lbs.

I contacted another paleo-artist named Carl Buell, who helped me make the Arctodus simus in the first place, to see if something was wrong with my Arctodus (like, maybe he needs over 500 lbs more of body fat!?!?)

His reply email explained how scientists rarely get to work with living animals (implying that they aren't good at guessing honest weights), and that he himself had already been aware that Arctodus body doesn't work out to be a 2,000 lb animal, and in actuality he estimated it probably rarely exceeded 1200 lbs (though he emphasized how it probably looked like it weighed a ton, because it was a solid muscular 1,200 lbs)... he added that humans like to think of ourselves as underdogs, and because of it we always get excited with big animals and we have a tendency to "overestimate"

After he sent me that email I did a little bit of digging on how that 2,000 lb weight estimate was achieved. It turns out the scientists used the femur of Arctodus simus yukonensis, and measured its girth, than they simply slapped on the ratio used to calculate autumn body weight of Grizzly bears based on femur girth, and BOOM 2,000 lbs of Heavy weight bear!!!!!!!! (Autumn weight is the fattest a bear can get, because at that point in time, they have "fattened up" for winter)

The problem is, Arctodus has HUGE legs for such a proportionately "small" body, and you can't take a big fat Arctodus femur, and expect to accurately estimate its weight based on the body ratios of a grizzly bear (which is built very differently from Arctodus) --- Furthermore I doubt Arctodus "fattened up" for the winter in a manner that was as extreme as grizzly bears do it. Arctodus was an open plains pacer, and it needed to stay relatively trim and fit all year around so that it could catch its prey, and cover vast distances to find food.

I think the scientists were so excited when they got to estimate the weight of such a "huge beast" (it is 5'6 at the shoulder after all, so it MUST be super heavy... right?) that they simply didn't feel like putting their estimation method into question... and nobody else does either which is silly, because every description also mentions how thinly built Arctodus was....




In my comparison image, it shows the late-summer weight of a "large" (but not record setting) modern Polar bear, opposite the polar bear is the largest specimen ever found of Arctodus simus, and behind the polar bear is an extinct pleistocene sub-species of polar bear (which kinda looked like a grizzly/polar hybrid, because it had several features in common with grizzlies as well).... --- In the autumn, both bears would be a little fatter, but I didn't want to show them super fat, I wanted to show them in their "healthiest" typical trim. No matter what season they are showed in though, even the modern polar bear is a "heavier set" animal than Arctodus, and it is capable of gaining more weight in fat, and even though it is shorter at the shoulder, it is longer, and I bet in the Pleistocene it was almost ALWAYS heavier. (today a typical polar bear would be smaller than a typical Arctodus though, and only the "larger" specimens of modern polars would exceed the Arctodus)

Any Paleo junkies out there, tell me what you think about this, because I'm sure you have heard of the 2,000 lb weight claims of Arctodus simus. If you think the scientific consensus is legit, and that I'm wrong, or missing something big, please feel free to share your reasoning, as well as a possible demonstration with your own artwork.
[x]

Devious Comments

love 0 0 joy 0 0 wow 0 0 mad 0 0 sad 0 0 fear 0 0 neutral 0 0

Comments


ĦĦĦUn excelente trabajo!!! :clap:
Very good... but... and the Ursus spelaeus? With 6'3" tall at the shoulder...

--
"The mankind needs the Earth, but the Earth doesn't need the mankind. The present shows the reality... Everything is in a system." :|

"Personally, it's not God that I don't like, but Their unbearable fan club."


Márcio Luiz F. Albuquerque
Hey, thanks for the comment, got any sources to back that up? All of my sources of skeletal specimens of U. spelaeus actually have shown me that it is quite short at the shoulder (photographs of museum specimens also show this), it was only about the height of a brown bear, 4' (but with thicker bones, which gives it a slightly heavier weight). Remember, I'm using the shoulder heights of the animal standing on all 4 limbs, not the shoulder heights of the animals standing on its hind legs.

Also if you look around hard enough on the internet you will find that many of the largest brown bears (kodiak bears) have bones that are larger than the largest cave bear specimens found to date. So, the cave bear is another animal that is highly blown out of proportion when it comes to size estimates.

My source for this 4' cave bear shoulder height is a .pdf I obtained that documents the actual museum specimen height of the animals, not bogus estimates.
The height of a brown bear... Just 4'? Well... photographs of museum specimens aren't the best references for your categorical reply.

This link: [link] shows a replica of a skeleton with 10' in upright position... with this, I think that 4' would be underestimate the height of a Ursus spelaeus…

I would be thankful, if possible, that you passed to me links with these information about the brown bear and cave bear…

--
"The mankind needs the Earth, but the Earth doesn't need the mankind. The present shows the reality... Everything is in a system." :|

"Personally, it's not God that I don't like, but Their unbearable fan club."


Márcio Luiz F. Albuquerque
You misunderstood me, the 4' shoulder height only applied to U. spelaeus, not to brown bears. And pictures of museums was not a source of mine for finding shoulder heights at all, I simply was suggesting that you look at some pictures of quadrapedally positioned museum specimens so that you could at least roughly see that it really was not very tall at the shoulder when standing on all fours.

And also, in case you were going to throw a "scale" picture at me, pictures that show this bear scaled alongside other bears are always depicting an "average" sized generic bear next to the "largest" specimens of U. spelaeus, which is not really a good or fair comparison. And also, some of the scaled images floating around are made by fanatics who believe all the mumbo jumbo about these bears weighing in over 1 ton, and being 12 feet tall, and I bet they even skewer the sizes to make them seem even more massive.

If I need to I will also dig up some of the most recent studies that have been done on U. spelaeus which conclusively show that early estimates of it's weight were highly overblown, and that this animal really was only marginally heavier than modern day brown bears, and "only" (still huge though) grew about the size of a modern kodiak bear.

I'm not saying it was a small bear, I'm just saying it wasn't the titan that early (but unaccurate) studies once showed it to be.

Arctodus simus on the other hand, is still claimed at being the largest bear of all time, and even modern studies are estimating its weight to be around 2,000 lbs. Since I'm no scientist, I could be blatantly wrong about Arctodus, because only myself and 1 other paleo-artist that I know of have openly stated our doubts about it's weight. But even scientific studies show that the largest specimens of U. spelaeus were not heavier than a typical kodiak bear in weight.

[link]

Here is my source for U. spelaeus 4' shoulder height. (1.22 meters)

And don't underestimate a 4' quadraped shoulder height. If you think it sounds small, it might be because your used to reading about overblown animal proportions. I'm sure if you saw a big 4' shouldered bear walking alongside you you would swear it weighed a ton, because a 4' shouldered bear can rear up to a staggering height on two legs. (4' of rear leg, and at least 5 or more feet of body and neck).... so now does the 4' shoulder height sound a bit more reasonable?
And I've got to make another comment now because I keep forgetting that I can't edit comments lol.

I just need to address a few other things that I didn't catch when I read your response the first time.

"with this [link] , I think that 4' would be underestimate the height of a Ursus spelaeus…"

there are two things things wrong with that... 1 is the assumption that 4' is my own, or a scientists "estimate" of shoulder height (it's not an estimate, it's the actual measurement of an adult museum specimen, the angellis.net .pdfs do not display an estimate unless they show a question mark trailing the numbers, if there is no question mark, than it was not an estimate, it was an actual measurement taken). And 2nd, I think you need to look more closely at the picture you showed me as evidence that the bear didn't have a 4' quadrapedal shoulder height.... Look at how short the legs are, and how long the torso is. Most of that height is coming from its long body, and those legs look quite stubby, so again, I see no indication that this animal had a shoulder height that was taller than 4'... If your still not convinced, and you want me to do one of those analytical breakdowns with a grid and a scale chart or something I can do that for you in photoshop and I promise I won't skewer the results just to make me look smart lol, I would do it fairly and unbiased.
*sigh.... and heres post number 3 because of the lack of an "edit comment" button

"The normal range of physical dimensions for a brown bear is a head-and-body length of 1.7 to 2.8 m (5.6 to 9.2 feet) and a shoulder height 90 to 150 cm (35 to 59 inches)"

That is an excerpt from the wikipedia brown bear page (which even though it is open source, a lot of pages are as good as a real encyclopedia)... I just wanted to show you that the average shoulder height of a brown bear actually does round out to be about 4' (1.2 meters), because you also gave the implication that 4' shoulder heights for a brown bear "didn't sound right" either.

The 90 cm - 150 cm shoulder height range probably encompasses all 3 U. arctos subspecies because the page speaks collectively for the group. From reading studies, I'm under the impression that brown bears weren't quite as heavily built as cave bears so to me, It isn't a far stretch to picture a thick boned, long bodied 120 cm Cave bear weighing as much as a 150 cm Kodiak bear
Nice seeing your Arctodus simus on wikipedia!

Site Map