WildFact
›
Premier Section
›
Edge of Extinction
ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)
ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)
|
ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)
|
 
A wild male Amur, probably dated more than hundred years old.
 *This image is copyright of its original author
The canine girth on that particular Amur Tiger looks exeedingly and proportionally thicker than that of a Bengal Tiger if the canines are at the same length.
For me, Amur Tigers seem to have the most thick-set canines out of any other feline when canine length is equated. (05-28-2016, 07:53 AM)Polar Wrote: The canine girth on that particular Amur Tiger looks exeedingly and proportionally thicker than that of a Bengal Tiger if the canines are at the same length. Yes, Amur tiger has by far the thickest and densest canines of all big cats, and the widest one is about 2 inches in diameter, that's comparable to the diameter of the 12 inches long saber of Smilodon populator. PS, its canine thickness is thicker than that of Smilodon populator.  *This image is copyright of its original author
 (07-31-2015, 10:09 AM)GrizzlyClaws Wrote: Some tiger mandible, can you identify its subspecies? @peter Grizzly When I read the thread recently, I noticed this post. I never responded to it, because the focus in the period you posted the photographs was on the series on tigers in northern India and Nepal. These posts took a lot of time. When I was done, I took a break and forgot about the question. Sorry about that. a - The question I'm afraid there's not much to go on. The reason is the unusual angles of the photographs. One also would have preferred a location. Here's what I see. One is the mandibula isn't concave or convex, but straight. Two is the tip (near the teeth) isn't lifted. This is typical for tigers. In wild lions, the mandibula is slightly convex in the centre and clearly lifted at the tip. b - Differences between skulls of captive and wild big cats Skulls of captive big cats often are different from skulls of wild big cats. Skulls of wild tigers very often have straightish or concave mandibulas, but I saw a number of skulls of captive tigers with both a convex mandibula and a lifted tip. I also saw skulls of captive lions with a slightly concave manibula and a straight tip. Most of these atypical skulls belonged to females. Not a few skulls of captive big cats are deformed. When I say 'deformed', I mean they are asymmetrical, relatively very wide, and 'underteethed' (referring to the canines in particular). They also often have superfluous growths. Skulls of adult captive big cats usually are shorter, not as elevated at the orbit and not as dense and heavy as skulls of their wild relatives. c - Differences between tiger subspecies The photographs you posted show a very smooth mandibula, meaning it most probably belonged to a wild tiger. If we include size, we get to male. When the length of the lower canines is added, I would get to adult. As for subspecies. In most tiger subspecies, the mandibula is either straight or concave. The tip of the mandibula also is never 'lifted'. In two subspecies, however, I noticed a few things seen in most skulls of wild male lions. In some mandibulas of wild male Sumatran tigers, I saw a slight downward depression halfway. This resulted in a slightly convex shape. The upper skull in some wild male Sumatran tigers also was a bit less 'tigerlike' in that the facial part was a bit longer than in other tiger subspecies. Furthermore, the profile of the upper skull often was flatter. If you would conclude skulls of wild male Sumatran skulls are more 'lionlike' than skulls of wild males of other tiger subspecies, I wouldn't object. Skulls of captive male Amur tigers also are a bit different from other tiger subspecies in that the upper skull often is a bit less vaulted as well as straighter (and more elevated between the eyes and the rostrum). They also often have straight and relatively long mandibulas. The most 'tigerlike' skulls are from Java and India. Males in particular often have very vaulted upper skulls and concave mandibulas. The upper skulls of wild male Java tigers often compare to old Greek helmets. Skulls from India and Java also compare in other respects. The shape, length and robustness of the upper canines is very similar. Male Amur tigers have the longest upper canines in absolutes but if we would divide the length of the upper canines by the condylobasal length, Sumatrans would top the list. Although the upper canines of Amur tigers are massive, especially at the insertion, the upper canines in many skulls of wild male Javan and, especially, Indian tigers are very close. They also seem to be a bit more curved. d - Conclusion For now, I'd say the mandibula above could have to belonged to an adult wild male Amur tiger (Panthera tigris altaica). Judging from the shape of the lower canines, I'd change 'adult' in 'oldish'. Although Amur tigers were widely distributed not so long ago (about two centuries only), I would go for northern or northeastern China or southeastern Russia. China seems more likely because of the size (Manchurian tigers often were a bit larger than Russian and Korean tigers). As to subspecies. Two centuries ago, China had P.t. tigris; P.t. corbetti; P.t. virgata; P.t. amoyensis and P.t. altaica. I think we can skip the first three. That leaves P.t. amoyensis and P.t. altaica. Panthera tigris amoyensis ranged from the region southwest of Amoy to central parts of China, whereas the southern part of Manchuria belonged to Panthera tigris altaica. But what about the other regions in northern China? I remember a reliable report about a wild male tiger shot in the sixties of the last century. This male was quite a bit larger than an average representative of P.t. amoyensis and about similar in size to an average adult male of Panthera tigris altaica. Based on the location where he was shot, he wasn't P.t. altaica. As we can also exclude P.t. virgata and P.t. amoyensis, the question is who he was. My guess is tigers in northern China were different from both P.t. amoyensis and P. t. altaica. Not saying P.t. styani should be re-instated, but there are a lot of questions. e - Skull 133 This skull belonged to an old male Amur tiger who was shot in a Belgium zoo. Greatest total length: 368,80 mm. - condylobasal length: 327,78 mm. - zygomatic width: 243,52 mm. - rostrum: 105,55 mm. - upper canines: 71,9 and 70,8 mm - weight: 2,120 kg. - elevation at the orbit: 171,90 mm. Before I saw it, I had measured and photographed a number of skulls of captive male Indian tigers (P. tigris tigris). These tigers were classified as 'true' Indian tigers. Although skull 133 had a longer face, longer canines and a wider rostrum, the Indian skulls were (relatively) more elevated at the orbit, wider and generally more massive. As you can see, skull 133 is a platform for the big guns. This is typical for many skulls of captive Amur tigers. The mandibula of this male, however, also was atypical in that it had a downward depression halfway and an elevated tip (most skulls of captive Amur tigers have straight or slightly concave mandibulas). Remember skulls of captive big cats seldom are representative:  *This image is copyright of its original author  *This image is copyright of its original author f - The 'Chanwangshai skull' This is a photograph of the largest skull of a wild male Amur tiger (from V. Mazak, 'Der Tiger', 1983) for comparison. At 16 inches in greatest total length, this skull was well over an inch longer than skull 133. It also was a lot wider, more elevated at the orbit and generally more robust. Compare to skull 133 and find the differences :  *This image is copyright of its original author
The skull is very vaulted, has a straight mandibula, a wide rostrum and large canines. Although not large and wide, the skull is quite massive. In spite of the well developed sagittal crest and a bit of wear on the teeth, the owner most probably wasn't very old. My guess would be P. tigris tigris.
Good find, Grizzly. Any particulars known?
No further information as I randomly found the video on YouTube, and my initial impression was also a Bengal skull.
Dishonest Dentition?
In another thread, I touched on the weak predictive power of dentition measurements when one is trying to determine the full specimen's size and mass. @GuateGojira kindly posted some data a long while back from several sources on tiger dentition somewhere in the annals of the internet. Being reminded of the topic, here is some data on the correlation dentition and skull size in P. t. altaica, P. t. tigris, and P. t. sondaica.  *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author It is interesting that the correlation is a bit different for each species. I would ignore the P. t. altaica M1 vs. GSL regression because the sample size is much too small. R-squared values are very weak for all subspecies for all teeth. In P. t. sondaica there is a significant correlation (p<0.05) between PM4 and skull length, however prediction is still weak. For all other measurements (bar the Amur M1 set), there is no significant correlation (p > 0.05).
1 - FAT
Quite many skulls I saw had similar dark-yellow and brown parts. In most cases, it turned out to be fat. This means the owner had died not that long ago. Although fat can remain for many decades, fossil skulls, as far as I know, never had any. It could turn out to be a non-issue, but one would like to know a bit more about those who found the skull. Same for the location. Could you find out a bit more, Grizzly? 2 - SPECIES As to species and subspecies. Based on what I saw, chances are the skull belonged to an Amur tiger. All features I consider to be typical are there. Tiger skulls often are dominated by vertical lines, sharp angles and vaults. Amur skulls, on the other hand, are dominated by straightish (horizontal) lines; a straight mandibula; elevation (at the orbit); a longish and straight snout; moderate width and a straight axis of vision. 3 - THE DIFFERENCE BETWEEN A LION AND A TIGER SKULL (males) a - Wild African lion and captive male Amur tiger Below is a comparison I did some years ago. The skull at the top belonged to a wild male lion, whereas the skull at the bottom belonged to a captive male Amur tiger. The tiger skull is a bit longer, but the difference is a few mm. only. The lion skull, as you can see, is dominated by the face, the limited vault (referring to the profile) and the convex mandibula. The profile of the Amur skull, although straight for a tiger, is a bit more vaulted and dominated by sharper angles and a straight mandibula. The lion mandibula, although seemingly shorter, is in fact longer:  *This image is copyright of its original author b - Wild Indian male tiger and wild Indian male lion This comparison is from the JBNHS. Indian tiger (Panthera tigris tigris) left and Indian lion (Panthera leo persica) right. You can see that the skull of the Indian tiger is more vaulted than the Amur skull, especially in the facial part. The sagittal crest is straight and long (not typical for Indian tiger skulls) and the general appearance is robust. Skulls of Indian tigers often are a bit wider across the arches and more massive. The skull of the male lion, again, is dominated by the long face, the elevated snout, the long and convex mandibula and the elevated axis of vision:  *This image is copyright of its original author 4 - SKULLS OF WILD AMUR TIGERS Nearly all Amur tiger skulls I saw had long or very long canines. Apart from skull size and angles, the was the most outspoken difference between Amur skulls and skulls of other tiger subspecies. This is why I concluded Amur tiger skulls, more than skulls of other subspecies, are big gun platforms. As to skulls of wild male Amur tigers. I'd advice to read this article. Although interesting all the way, the photographs of the skulls are remarkable in particular. The reason is photographs of skulls of wild Amur tigers are quite rare: http://bigcats.ru/forum/viewtopic.php?t=4292 5 - THE SKULL YOU POSTED I agree the skull most probably belonged to a male, because of the width and strength of the rostrum and the size of the upper canines. Sexual dimorphism in Amur tigers is outspoken. Same in skulls. Here, to finish the post, a photograph of the skull of another captive male Amur tiger. As you can see, it's in many respects very similar to the skull you posted:  *This image is copyright of its original author
Unfortunately, no further information available for the skull, since I got it from a random poster in Baidu.
The new skull does have robust teeth, maybe it is a wild specimen?
The robust arches, the long and elevated snout and the width of the upper canines strongly suggest the skull belonged to a wild male. In spite of that, I propose to wait for more information. As collectors often communicate about skulls, chances are there could be a magazine. If so, we got to find it.
@peter
Very interesting and enlightening article. We've had this debate before and even made a thread on it "hands on or off" and I think that article makes it abundantly clear..... Hands off!!!! There is no more need for morphological study of wild tigers, or any big cats for that matter. If you want to study them, do it, just in a manner that is not detrimental to the cat. That means absolutely no capture! |
| Users browsing this thread: |
| 75 Guest(s) |