Who is the "king" of tigers? - Bengal or Amur

[peter]

(09-12-2015, 04:49 PM)Thebingthing Wrote: I have a Bengal tiger skull from a large male 284cm long and 229cm wide, but the skull is enormous. It was an old skin rug from 1936 that needed restoration and I had the skull taken out. It measures approximately 44cm long and 36cm wide. I have only one of the two upper canines which I don't believe are particularly long but with full root is total of just under 14cm around the curve or 12cm straight.

Am happy to talk to anyone who wants to know more or for verification - my measurements are not particularly accurate as just done with a workmans retractable tape measure.

Let me know if you're interested.

Jonathan

Welcome to the forum and and thanks for the contributions, Jonathan. Hope you're here to stay.

Not all of us have rugs and skulls of Indian tigers. My gut feeling says there's more where that came from. If so, please don't hesitate to inform us. We're most interested.

The photographs you posted are much appreciated. Based on what I saw, I'd say you're right regarding India. The upper skull is very vaulted, which is typical for many Indian tiger skulls. As I didn't see superfluous growths typical for many skulls of captive tigers, my guess is the skull belonged to a wild Indian tiger. Judging from the length, I'd say it was a male. Any idea how and when the owner of the skull was killed? Anything known on the circumstances? The hunter?

You wrote the tiger was 284 cm. My guess is this measurement refers to the skin, as you also said the width was 229 cm. Correct? Anything known on the total length of the tiger when he was shot? If so, can you find out if the tiger was measured 'over curves' or 'between pegs'? Was the tiger weighed?

As for the skull. I noticed the sutures are not closed. I compared the photographs to others and concluded the owner still had some growing to do when he was killed. My guess would be a young male, not quite adult. Another reason to get to that conclusion is in the length of the upper canines. Those of adult wild adult male Indian tigers usually well exceed 50 mm. measured from the gum line (referring to the white part of the upper canine). The amount of wear also was quite limited.

A pity the last end of the sagittal crest was damaged, but you could still measure the skull. 


1 - Greatest total length

Remove the upper skull from the mandibula and place it in your lap. Measure the distance between the tip of the maxillary bone (just above the insertion of the incisors) to the tip of the sagittal crest in a straight line. When you have the correct line (lateral view), check it from above. Make sure the incisors are excluded.  

It isn't easy to measure the greatest total length, because the large upper canines create an angle when you place the skull on a table. You can remove the angle by using the right equipment and moving the skull to your lap. Find a scale of 20 inches or thereabout. It has two long teeth that extend downward. Both teeth have tips that can be inserted in the skull. Insert the tip of the first tooth just above the incisors and use the downward extention of the second tooth (not the tip) directly behind the sagittal crest. You now have the correct line. Move the skull to a flat surface and measure the distance in a straight line. The line needs to be horizontal when you measure it. If you don't have the equipment needed, go to a museum (ask for the conservator) or a university. Many would be interested to see the skull of a wild Indian tiger.  


2 - Condylobasal length 

You need the scale mentioned above to measure the condylobasal length. Here's the procedure. Place the upper skull in your lap and turn it upside down. Insert the tip of the first tooth directly behind the insertion of the incisors. The second tooth has to be inserted directly behind the condylae. When done, move the skull, still turned upside down and with the two teeth inserted, from your lap to the table. Ask someone hold the skull (as it will rock on the table) and check if you inserted the teeth at the correct points. Now measure the distance on a horizontal line. Repeat the procedure to make sure.  

Most biologists prefer the condylobasal length over the greatest total length, because it reflects the true length of the skull. When the greatest total length is measured, age is incorporated (older animals usually have longer crests than young animals). 


3 - Zygomatic width

In order to measure the width of the skull at the arches, you need the extentions of both teeth of the scale, not the tips. Remove the upper skull from the mandibula and place it on your lap. Select the widest point, press both teeth against the arches and measure the distance in a straight line. You can also measure it on a flat surface (a table) with the upper skull placed on the mandibula. You will notice that the measurement often will be slightly increased (1-2 mm.). The reason is the angle.


4 - Weight

I would be much interested in the weight of the skull. Any scale would do.


5 - Rostrum

In tiger skulls, the maxillary bone usually extends towards the canines. In order to measure the width of the rostrum, you need a scale with two teeth again. A small one would do this time. Now for the procedure. Turn the front of the skull towards you and mark the outer edge of both canines on the maxillary bone (the snout) just above the upper canines. Now watch the markers you placed on the maxillary bone from above. Extend them 0,5-1,0 cm. and measure the distance between both. Make sure they are on the widest part of the maxillary bone, just above the upper canines, but not quite at the end. Measure the distance between both markers in a straight line.


6 - Upper canine width

In order the measure the width of the upper canines, you need a small scale with two teeth. Place one at the front of the canine and the other at the back. Measure the distance between both teeth. Make sure you measure the distance at the insertion of the upper canines.


7 - Pm4

The Pm4 is the last molar in the upper tooth row (upper jaw). Measure the distance between the front and back in a straight line and use the small scale. 


8 - Height at the orbit

This is the height of the skull at the heighest point (usually close to the orbit). In order to measure the distance, you need the complete skull. Measure the distance between the heighest point and the table in a straight line. In order to make things easier, place something on top of the skull. A small scale would do just fine. 


9 - More information

You can go to post 676 in the thread 'On the Edge of Extinction' (tigers) to read a bit more about skulls and methods to measure them. There are more posts about skulls close by.

As to the size of skulls of adult male tigers. Most skulls of wild male Indian tigers range between 320,00 - 375,00 mm. in greatest total length. The longest I know of, all measured by well-trained Forest Officers and experienced taxidermists (like Van Ingen), ranged between 380,00 - 399,00 mm. One male tiger shot in northern India by Sir John Hewett's daughter had a skull of 16,25 inches in greatest total length. This tiger was 10.2 'over curves' in total length, measured half a day after he was shot. Although exceptional, it wasn't as wide as your skull. Skulls of captive male Indian tigers usually are shorter, relatively wider at the arches and a bit lower at the orbit. The upper canines often are shorter and narrower.

Skulls of wild male lions usually are a bit flatter and longer. In most lion skulls, the maxillary bone narrows a bit towards the upper canines. When placed on a flat surface, lion skulls often 'rock'. The reason is the mandibula often is a bit convex. The mandibula in a tiger is either straight or slightly concave. In skulls of captive big cats, however, anything is possible.    

If you want to know more, don't hesitate to ask. Good luck and thanks in advance,

Peter. Reply