Welcome Guest [Log In] [Register]
Welcome to Carnivora. We hope you enjoy your visit.


You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are some features you can't use. If you join our community, you'll be able to access member-only sections, and use many member-only features such as customizing your profile and voting in polls. Registration is simple, fast, and completely free.


Join our community!


If you're already a member please log in to your account to access all of our features:

Username:   Password:
Add Reply
Who wins?
South American Giant Short-faced Bear 5 (31.3%)
Euoplocephalus tutus 11 (68.8%)
Total Votes: 16
South American Giant Short-faced Bear v Euoplocephalus tutus
Topic Started: Jan 24 2014, 09:20 PM (3,500 Views)
Taipan
Member Avatar
Administrator

South American Giant Short-faced Bear - Arctotherium angustidens
Arctotherium is an extinct genus of South American short-faced bears within Ursidae of the late Pliocene through the end of the Pleistocene. They were endemic to South America living from ~2.0–0.01 Ma, existing for approximately 1.99 million years. Their closest relatives were the North American short-faced bears of genus Arctodus (A. pristinus and A. simus). The closest living relative would be the Spectacled bear (Tremarctos ornatus). Arctotherium was named by Hermann Burmeister in 1879. It was assigned to Tremarctinae by Krause et al. 2008.[2] A specimen of A. angustidens from Buenos Aires shows an individual estimated, using the humerus, to weight between 983–2,042 kg (2,170–4,500 lb), though the authors consider the upper limit as improbable and say that 1,588 kg (3,500 lb) is more likely, however, using the radious, the mass estimate shrinks to a maximum of 1,108 kg (2,440 lb). Independently of the method it is possibly the largest bear ever found and contender for the largest carnivorous land mammal known to science.

Posted Image

Euoplocephalus tutus
Euoplocephalus (play /juːˌɒplɵˈsɛfələs/ ew-op-lo-sef-ə-ləs; Greek: eu-/ευ- meaning 'well', hoplo-/οπλο- meaning 'armed' and kephale/κεφαλη meaning 'head', "well-armored head") was one of the largest genera of ankylosaurian dinosaurs, at about the size of a small elephant. It is also the ankylosaurian with the best fossil record, so its extensive spiked armor, low-slung body and great club-like tail are well documented. Among the ankylosaurids, Euoplocephalus was exceeded in size only by Tarchia and Ankylosaurus. Euoplocephalus was 6 metres (20 ft) long and weighed about 2 tonnes (2.2 short tons). It was also 2.4 metres (7.9 ft) wide. The head and body of Euoplocephalus were covered with bony armor, except for parts of the limbs and possibly the distal tail. Much of this armor was made up of small ossicles. Larger flat scutes, conical plates, and disc-shaped plates were arranged in transverse bands among this pavement of ossicles. Two bands protected the dorsal and lateral surfaces of the neck, four were present across the front part of the torso, three protected the pelvis, and four were present on the anterior half of the tail. The banded arrangement is thought to have permitted some freedom of movement.

Posted Image




Catboy
Jan 24 2014, 05:55 AM
Arctotherium vs Euoplocephalus
Offline Profile Quote Post Goto Top
 
Carcharadon
Member Avatar
Shark Toothed Reptile
[ *  *  *  *  *  *  *  * ]
Mismatch in favor of euoplocephalus. Arctotherium is much smaller than most would think it is.
Offline Profile Quote Post Goto Top
 
Ausar
Member Avatar
Xi-miqa-can! Xi-miqa-can! Xi-miqa-can!
[ *  *  *  *  *  *  *  * ]
I forgot how big Arctotherium really was, I'm almost certain someone by the likes of blaze said things about its size, so I'm not sure.
Offline Profile Quote Post Goto Top
 
The All-seeing Night
Member Avatar
You are without honor
[ *  *  *  *  *  *  *  * ]
Really is a mismatch. The armored dinosur has much better protection and a more potent weapon.
Offline Profile Quote Post Goto Top
 
blaze
Carnivore
[ *  *  *  *  *  *  * ]
@dinopithecus
Yes, A. angustidens is not that big, for the biggest known specimen, that extra heavy weight estimate is caused a little bit by the humerus having a big pathology in the shaft, and that most bear specific regression equations for bear's mass are based on, arguably, overweight/obese bears.

Since estimating mass is hard, I'll not do it but to get a realistic idea of its size, knowing how tall it was is helpful.

First let's get a base, the A. simus specimen FMNH PR24880 has a scapula, humerus and radius 409mm, 580mm and 436mm in functional length respectively, which gives us a shoulder height of 142.5cm, this is some centimeters less than the actual one though as that one also includes the height of the hands, flesh, cartilage and stuff.

For A. angustidens, in the internet you can find a lot of people claiming 6ft (1.82m) and some even 7ft (2.13m) but this "estimates" are baseless, functional length of the humerus is ~596mm and that of the radius is ~450mm, this measurements are only ~3% more than in FMNH PR24880, if we estimate the scapula to be 420mm tall, then we get a shoulder height of 146.6cm, actual shoulder height was probably no more than 155cm.

For comparison the biggest brown bear in an 80's survey of Yellowstone Park was 117cm tall and weighted 325kg in august, thanks to its foraging of garbage dumps during all the summer months (Blanchard, 1987), if we isometrically scale it to 155cm at the shoulder it’ll only weight 750kg, so how likely is for the largest A. angustidens to be 1.6 tonnes at the same height?
Edited by blaze, Jan 25 2014, 05:03 PM.
Offline Profile Quote Post Goto Top
 
Ursus arctos
Autotrophic Organism

blaze
Jan 25 2014, 04:58 PM
For comparison the biggest brown bear in an 80's survey of Yellowstone Park was 117cm tall and weighted 325kg in august, thanks to its foraging of garbage dumps during all the summer months (Blanchard, 1987), if we isometrically scale it to 155cm at the shoulder it’ll only weight 750kg, so how likely is for the largest A. angustidens to be 1.6 tonnes at the same height?
I'll add that the brown bear's shoulder hump, if it interferes, at least does not bias the results compared to black bears.
Eg, the two heaviest black bears from the Khutzeymeen Valley Grizzly Bear Study:
BM01, 7 years old, 125 kg, shoulder height 94 cm
Scaling to 155 cm: 560 kg

BM14, 12 years old, 135 kg, shoulder height 107.5 cm
Scaling to 155 cm: 405 kg

I do think 405 kg is far too small - its bones are far and beyond larger than those of extant brown bears, for which 444 mm and 520 mm are the largest humerus and femur measurements, respectively, that I'm aware of.
Both are listed in Sorkin's 2006 study on the Ecomorphology of bear dogs.
Offline Profile Quote Post Goto Top
 
Ausar
Member Avatar
Xi-miqa-can! Xi-miqa-can! Xi-miqa-can!
[ *  *  *  *  *  *  *  * ]
Yep, Euoplocephalus is at least more than twice the weight and is armed with a tail club that could hit with a force of 7,281-14,360 Newtons (apparently 3-7 times the necessary force to break bone) (1, 2). It wins easily, around 90% of the time, if not more.
Edited by Ausar, Jan 26 2014, 04:01 AM.
Offline Profile Quote Post Goto Top
 
blaze
Carnivore
[ *  *  *  *  *  *  * ]
@Ursus arctos

Indeed, and that bear is pretty big, is it FMNH 63802 right? Davis (1964) "The giant panda, a morphological study..." gives more measurements, its skull has a condylobasal length of 433mm and a greatest length of 450mm.
Edited by blaze, Jan 26 2014, 05:08 AM.
Offline Profile Quote Post Goto Top
 
Vivyx
Member Avatar
Felines, sharks, birds, arthropods
[ *  *  *  *  *  *  *  * ]
Wow, I actually didn't know that Arctotherium was downsized. The dinosaur wins easily. It's armor would protect it from the bear's attacks and it can easily break the bear's legs. But the thing I am trying to wonder is that how is the dinosaur going to kill the bear with just blunt trauma? I can see it maybe smashing it's face or smashing some ribs, or maybe doing some heart damage. But probably not a death, but again I could be wrong. I see the bear being easily intimidated, retreating because of wounds or maybe dying from it's wounds. The bear is definitely something you don't want to fuck around with, but I say that it is probably running off because of the force coming from a club like this:



Posted Image



I see the bear retreating away from the dinosaur after the dinosaur starts clubbing at the bear, or otherwise it dies 8/10. I say dinosaur, but if we were using the Arctotherium from the OP then it would be a closer fight, it would be dinosaur 6-7/10 then.
Online Profile Quote Post Goto Top
 
Ausar
Member Avatar
Xi-miqa-can! Xi-miqa-can! Xi-miqa-can!
[ *  *  *  *  *  *  *  * ]
Perhaps if it hits the bear's head with its club, it could smash the skull.
Offline Profile Quote Post Goto Top
 
blaze
Carnivore
[ *  *  *  *  *  *  * ]
It hasn't been downsized "officially" as no scientific paper has noted this yet but with the info we have is obvious it wasn't that big.

Like dinopithecus already said, according to Arbour (2009) a hit by the tail club of a large ankylosaurid had several times the force necessary to break bone so a hit will not necesarly produce only blunt trauma.
Offline Profile Quote Post Goto Top
 
retic
Member Avatar
snake and dinosaur enthusiast
[ *  *  *  *  *  * ]
Euoplocephalus wins this quite easily. it is much larger, has armor, and it can cause a serious amount of damage with that club.
Offline Profile Quote Post Goto Top
 
Bob5
Member Avatar
Autotrophic Organism
[ *  * ]
The din wins easily here: armor + club like tail
Offline Profile Quote Post Goto Top
 
BoomerSooner
Member Avatar
Heterotrophic Organism
[ *  *  * ]
Euoplocephalus easily.
Offline Profile Quote Post Goto Top
 
Superpredator
Member Avatar
Apex Predator
[ *  *  *  *  *  *  *  * ]
The Dino is too powerful and well protected. Dino 8/10
Offline Profile Quote Post Goto Top
 
1 user reading this topic (1 Guest and 0 Anonymous)
ZetaBoards - Free Forum Hosting
Create your own social network with a free forum.
Learn More · Sign-up Now
Go to Next Page
« Previous Topic · Interspecific Conflict · Next Topic »
Add Reply