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GrizzlyClaws

Posts: 120 Member Since:relative

#201 [url]

Jan 31 14 7:14 AM

GuateGojira wrote:
GrizzlyClaws wrote:
Also, "Amur" from the Duisburg zoo didn't have the longest head+body length, but he has the biggest head by far.

As tigerluver pointed out before, due the different genome combination, he is a clone of the Wanhsien tiger, just like Baikal is a clone of the Ngandong tiger.

In the same way, the largest tiger in body size (Amur from Prague) has the smallest skull (371 mm). I think that it is only body variation caused by an unknown mix of genes.

 

I don’t think that Baikal is the same case, and it is too risky to establish conclusion that are based only in assumptions.

 

I think that Peter conclusions fit better here, that there are two groups of captive Amur tigers, those with large head and relative short body and those with smaller heads and larger bodies. Baikal and the two Amur (Prague and Duisburg) are exceptional cases, with extreme bodies or heads, all the other captive specimens fit very well in the normal grow of the Amur tigers.

 


Baikal's head seems to proportionally normal, but overall his head must be huge.

And "Amur" from the Duisburg zoo has huge head, but his head+body is considerably smaller than Baikal.

So this overall leads some interesting observation for the different body type of the modern Amur tigers.



  

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#202 [url]

Feb 1 14 2:38 AM

GrizzlyClaws, I found this interesting quote:

 

“The South China tiger is believed to have a more archaic skull, whose ratio of the length and width is relatively larger than other tiger subspecies. Its body is slim with a slender waist. It is distinguishable from other tiger subspecies by its narrower face, longer nose, more intense orange color, short fur, longer legs, and shorter & broader stripes which are spaced far apart compared with those of Bengal and Siberian tigers.”

 

Source: http://english.savechinastigers.org/node/31

 

Obviously, I searched in my database and this is what I found:

 

Subspecies              Ratio GSL-ZW   Sample

P. t. amoyensis       1.47                            6

P. t. corbetti               1.46                            3

P. t. sondaica           1.43                            13

P. t. altaica                1.44                            13

P. t. tigris                   1.41                            18

 

Incredibly as it is, it seems that this is correct, as the largest ratio came from the South China tigers (1.47). This means that the South China tigers had a narrow skulls in comparison with the other “modern” subspecies. The second narrower group is that of Indochinese tigers, but with such a small sample (3) it is too early to achieve any final conclusion.

 

It seems that the first tigers had narrow skulls, a trait that probably presented also the Wanhsien tiger and is now show in P. t. amoyensis. The second tiger group in evolve is that of Indochina, with also narrow skulls. The later mainland groups have much wider skulls with P. t. tigris presenting the smallest ratio.

 

Sunda tigers seems that had changed very much trough they evolution. The Ngandong tiger had a ratio of 1.62, very narrow for any modern tiger, but latter Javanese forms seems to had increased they skull wide and carnassials’ size, but also developed smaller sagital crest and narrow occipital areas. It is obvious that Sunda tigers had different masticator systems in comparison with mainland populations.

 

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GrizzlyClaws

Posts: 120 Member Since:relative

#203 [url]

Feb 1 14 2:52 AM

Interesting, it seems that both lion and tiger clade cats have followed a parallel pattern of morphological evolution.

The more primitive Cromerian lion also has proportionally narrower skull compared to its late successors.

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#204 [url]

Feb 1 14 6:25 AM

Hello everyone!

I don't have time to post much but I believe the parallel between the tiger and lion skull evolution stems from the mutual relationship to P. palaeosinensis. Look at the relative narrowness of the skull:
image

Judging by the accepted theory of cats evolving from weasel type creatures, long, narrow skulls in the earliest of Felidae makes sense.

With that, it is probable that the long skulls of tiger-clad and lion-clad found from the Pleistocene, especially the early, probably were proportionately lighter than their modern relatives, and by quite a bit, judging from the skull length to width proportions.

Regards.

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#205 [url]

Feb 5 14 11:45 PM

Proportions of the tiger – head length

Check this image of Baikal:

image

 

As we can see, the head-body length of this tiger is about 5 times its head length. Take in count that the body of Bailkal is crouched, so if it were stretched, they will match perfectly with the five bars on its back.

 

This suggests that Mazák assumption that the large Amur tigers had heads that represents about 1/5 of the head-body seems to be correct. Now, let’s see if this value is accurate.

 

Now, check the proportions of “head-body – head length” the other captive Amur tigers:

* Amur No. 11: 4.89

* Benjamin No. 102: 4.79

* Amur No. 143: 4.20

Average ratio: 4.63 – range 4.20-4.89

 

This is close to the 1/5 estimated by Mazák. Sadly, these are the only captive specimens that have its head-length available.

 

Now, let’s use the CBL of all the specimens, including those of Dr Christiansen, to achieve the ratio of “head-body – CBL”:

* CN5698: CBL=350.9 mm – HB-CBL= 5.81

* CN5697: CBL=334.2 mm – HB-CBL= 6.16

* CN6049: CBL=337.8 mm – HB-CBL= 5.77

* Amur No. 11: CBL=322.5 mm – HB-CBL= 6.82

* Benjamin No. 102: CBL=331.2 mm – HB-CBL= 6.07

Average ratio: 6.13

 

I consider these measurements more reliable, as are based in the actual bones compared with the body length. Head-length only is very variable and can change depending of the musculature of the face. Body length can change to, but the difference in musculature is less than in the head.

 

Now, the wild ones, to get the “head-body – head length”:

Zheny-1: HL=41 cm – HL-HBL= 4.78

Dale: HL=45 cm – HL-HBL= 4.44

Aleksei: HL=41 cm – HL-HBL= 4.51

Igor: HL=46 cm – HL-HBL= 4.39

Maurice: HL=41 cm – HL-HBL= 5.07

Sasha: HL=48 cm – HL-HBL= 4.13

Misha: HL=46 cm – HL-HBL= 4.17

Valodia: HL=43 cm – HL-HBL= 4.51

Andrey: HL=40 cm – HL-HBL= 4.98

Victor: HL=38 cm – HL-HBL= 5.00

Zheny-2: HL=37 cm – HL-HBL= 4.81

Average ratio: 4.62 – range 4.13-5.07

 

Interesting both captive (4.63) and wild (4.62) specimens have about the same “head-body – head length” proportions. The range of wild specimens is more variable because the sample is larger.

 

This data show that Mazák was correct, as 4.6 is just slightly less than the 1/5 estimated by him. Sadly, we don’t count with this data for the other tiger populations.

 

Taking in count that we estimated an average head-body length (in straight line) of 233 cm, based in the large femur, for the largest Ngandong tiger, we can obtain the head length based in the Amur tiger ratios:

* Wild specimens: ratio 4.62 – head of 504 mm.

* Captive specimens: ratio 4.63 – head of 503 mm.

 

Now using the average ratio of 1.16 like the relation of “head length and GSL”, we can get the following GSL estimations:

* Wild specimens: 504 mm / 1.16 = 434.5 mm.

* Captive specimens: 503 mm / 1.16 = 433.6 mm.

 

The average GSL would be of 434 mm, which is only 6 millimeters less than the previous estimation of 440 mm. This is evidence that tigers are very symmetrical animals and there is no doubt that these same proportions are shared with all the other tiger populations.

 

So, here are the body proportions of the tigers, based in Amur specimens:

 

* Head-body length – head length = 4.62

* Head-body length – Condylobasal length = 6.13

* Head length – greatest skull length = 1.16

 

Obviously these values can be variable depending of the specimens, but at least they are useful to estimate body size of extinct Pleistocene tigers.

 

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GrizzlyClaws

Posts: 120 Member Since:relative

#206 [url]

Feb 6 14 12:16 AM

I agree that the mean of the deviation is about 17 inches for a tiger of the size of Baikal, 16 inches for the lowest est and 18 inches for the highest est seem to be correct.

It is interesting to see that the skull difference between the Pleistocene tiger/lion is pretty similar to the modern one.

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GrizzlyClaws

Posts: 120 Member Since:relative

#207 [url]

Feb 6 14 12:22 AM

I think the size of the canine teeth also correlated with the GSL.

If a specimen with proportionally larger canine, then his GSL est would indeed lean towards the higher one.

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#208 [url]

Feb 6 14 6:49 AM

Proportions of the tiger – Sunda tigers


You will remember the document of Sody (1949) that presents a large database of tiger skulls from Sumatra, Java and Bali. Besides, it presents the body size of 13 specimens, 9 of them associated with its skull.

 

Here is the full list of specimens:

 

Specimens () CBL  GSL HB TL HB-CBL HB-GSL TL-HB Between pegs Origin
Tjerinti, Sumatra 305.3 345.0 1600 2370 5.24 4.64 1.48 Yes Wild
Sungei K, Sumatra 296.5 335.0 1765 2520 5.95 5.27 1.43 Yes Wild
No. 107/37, Sumatra 263.0 297.0 1600 2300 6.08 5.39 1.44 Yes Captive
Udjung Kulon , Java 294.0 331.0 1800 2700 6.12 5.44 1.50 Yes Wild
Average           5.85 5.18 1.46  










Specimens () CBL  GSL HB TL HB-CBL HB-GSL TL-HB Between pegs Origin
Padang, Sumatra 242.0 271.0 1358 2108 5.61 5.01 1.55 Yes Wild
Benkulen, Sumatra 245.5 271.0 1550 2200 6.31 5.72 1.42 No
Gaol, E. Java 243.0 272.0 1690 2380 6.95 6.21 1.41 No
Bali - 254.0 1530 2110 - 6.02 1.38 No
Bali 242.5 269.0 1770 2460 7.30 6.58 1.39 No
Average           6.54 5.91 1.43  
Reference: Sody, 1949.







Note: The correlation between GSL-CBL in  the male Sumatran (r=0.98, n=4) tigers is high, so the reconstruction of the missing values (in orange) is highly reliable.

CBL-Condylobasal length; GSL-Greatest skull length; HB-head and body length; TL-Total length.


Interesting as it is, the values of the male Sumatran specimens are all lower than those of the Amur tigers, suggesting that this race had a relative larger head in relation to its body. On the other hand, the only Javanese male tiger available match perfectly with the average values of the Amur tiger, suggesting that this “pure” race of Sunda tigers kept the same proportions than the mainland tigers. The Sumatran tigers, been a natural hybrid of mainland and Sunda tigers, probably evolved a different body proportions and completely different cranial characteristics, that have been presented by Mazák & Groves (2006) and Mazák (2008).

 

The values of the females are more confuse as there are not comparison parameters, as with the males. Only one female (Padang, Sumatra) fit well into the ratios of the male specimens, but the other specimens, especially those from Bali, are obviously very inflated and represent specimens measured “over curves” or from skins.

 

As we don’t know the proportions of skull-body for females, it is difficult to get an accurate conclusion, especially in the case of the other two specimens from Sumatra and Java.

 

Conclusion:

We can conclude that Sumatran tigers seem to have larger heads in relation to its body, probably comparable to the African lions (My own data, unpublished). This proportion is shared also with the only female tiger apparently also measured between pegs.

 

The measurements of the two Bali tigresses are definitely not reliable and were taken from skins or over curves. This was clearly stated by Mazák in two documents.

 

As for the Javanese tigers, only the male seems to have been measured between pegs. The female skull, using the ratio of the male and those of the Amur tigers, gives a head-body of c.1470 mm, which is 22 cm less than the presented figure, which suggests that the measurement was taken from a skin.

 

For comparison, three South Chinese tigers, measured between pegs, present the following ratios:

 

Location       GSL                HB                  Ratio

Amoy-1          343                 1850               5.39

Shanxi           346                 1990               5.75

Amoy-2          321.7              1760               5.47

Average                   5.54

 

It seems that the Javanese tiger (5.44) is slightly less than the average ratio from China, and these last two fit perfectly between the ratios of the Amur race (5.19-5.93).

 

Mainland tigers (Amur and China overall) seems to have a ratio of 5.47 (n=8) between the Greatest Skull Length and the head-body length. For the only Javanese male tiger (5.44) the figure is the about the same and suggests a similar evolutionary pattern that probably arises for the first time in the last (and largest) specimens of the Wanhsien tiger. If we put together the five Amur, 3 South China and 1 Javanese specimens, the ratio of head-body - GSL is of 5.46.


We can conclude, with some degree of certainest, that we can multiply 5.46 (or 5.5 if you want just one decimal, the difference in the result is minimal) to any GSL specimen and we will have a plausible head-body length in straight line. smiley: wink



 

Last Edited By: GuateGojira Feb 6 14 7:19 AM. Edited 1 time.

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#209 [url]

Feb 6 14 8:13 AM

Proportions of the tiger – the new ratio reliability

Now that we have a ratio of 5.46 for the “Head-body – GSL” for the tiger (Amur, China and Java together), we can prove this value with known specimens.

 

Did you remember the Gondol tiger?

image

Source: Buzas & Farkas, 1997.

 

This is the largest Balinese tiger on record with a GSL of 312 mm, slightly larger than the largest skull recorded for the Venezuela jaguars of Los Llanos (312.5 mm GSL and 1700 mm in Head-body “between pegs”). The head-body of this large tiger is reported as 1740 mm. If we apply the new ratio, we get:

 

GSL 312 * 5.46 = 1704 mm.

 

As we can see, the result is just slightly smaller (less than 4 cm) than the reported size. Although the hunter (Vojnich) doesn’t report the method of measurement, this data suggest that it was taken in straight line. The total length was of 245 cm, which is slightly longer than the record calculated by Mazák (230 cm). Please take in count that Mazák never knew about this large skull.

 

At the end, the result was slightly lower, but overall it was accurate.

 

Now, let’s prove with other large skulls:

 

* Record Bengal from Mazák – 378 mm = 2064 mm HB.

* Record Amur from Mazák – 383 mm = 2091 mm HB.

* Record Amur from Kitchener – 406 mm = 2217 mm HB.

* Record Bengal from Hewett – 413 = 2255 mm HB.

 

These results match very well with the known maximum sizes for the species. For example, the longest Bengal tiger measured by scientist (HB) was of 204 cm (Karanth, 1993), while the largest Amur was of 208 cm (Kerley et al, 2005). For the old records, the longest Bengal tiger was of 221 cm in HB (Brander, 1923), while the longest Amur tiger reported by Mazák (1981) was of probably about 220 cm in HB (total length of 330 cm).

 

These are only a few examples that shows that the ratio of 5.46 produce reliable results. However, we must take in count that even when tigers are very symmetric animals, there are variations. For example, the longest tiger on record between pegs (322 cm in total length; 213 cm in head-body) had a skull length of 381 mm, which produce a ratio of 5.59. This fits very well with the overall data, but is higher than my new ratio.

 

Like a form of conclusion, I will quote Sterndale (1884):

I quite expect to be criticized, but if the crude idea can be improved on by others I shall be glad”.

 

I think that his words apply very well to my hypothesis. With more data, this method and ratio will be better in the future. Greetings to all. smiley: smile

 

Last Edited By: GuateGojira Feb 6 14 8:16 AM. Edited 1 time.

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GrizzlyClaws

Posts: 120 Member Since:relative

#210 [url]

Feb 6 14 11:16 AM

There is a deviation of the lowest and highest estimation of the skull.

If the mean for the largest specimen is around 17 inches, then it is 16 to 18 inches from the lowest to the highest deviation.

I think tiger's skull probably max out at 18 inches as the highest deviation for the largest specimen.

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