WildFact
›
Information Section
›
Extinct Animals
›
Pleistocene Big Cats
Freak Felids - A Discussion of History's Largest Felines
Freak Felids - A Discussion of History's Largest Felines
|
Freak Felids - A Discussion of History's Largest Felines
|
Sorry, I believed that you were talking about the canine of the mandible, not about the large one in the beginning of the page.
Yes, that is a large upper canine. The modern canines are also very large, c.6 cm to the gum line is very impressive. I also think that the Pleistocene tigers in northern China were of the same size than modern Amur tigers and Bengal-Nepal specimens. Imagine a tiger of 220 cm in head-body, 110 cm in shoulder height, a skull of c.400 mm in greatest length and a body mass of up to 272 kg. These are the largest measurements recorded for Bengal and Amur tigers, and I think they were also the dimensions of the large Pleistocene Chinese specimens, specifically the Wanhsien tiger (P. t. acutidens). Just the Ngandong tiger (P. t. soloensis) surpassed this size, although we can't forget the huge tiger fossil skull from Manchuria, a hidden treasure, lost for the science.... for the moment.  (08-16-2015, 05:04 AM)GuateGojira Wrote: Sorry, I believed that you were talking about the canine of the mandible, not about the large one in the beginning of the page. The mysterious huge tiger skulls have been found everywhere in China, from the central area to Manchuria. Just all of these fossil treasures were lost and didn't get treated properly.
The collection of the tiger canine teeth, and some of these look quite old at the point to turn into the subfossil.
Do you notice that all old tiger teeth are super massive? The robustness is unmatched, and I didn't even see such robustness from the Cave lion's canine teeth.  *This image is copyright of its original author
@GrizzlyClaws
According to Driscoll et at. (2009), your theory on the neo Amur from Caspian is very plausible, "with a secondary distinctive expansion eastwards (route D) colonizing the historic range of P. t. altaica in the Russian Far East." :  *This image is copyright of its original author They also put the theory in words, stating that "less than 10,000 years ago the Caspian/Amur tiger ancestor colonized Central Asia via the Gansu Corridor (Silk Road) from eastern China then subsequently traversed Siberia eastward to establish the Amur tiger in the Russian Far East." Driscoll et al. sets the subspecies boundaries below Manchuria. The official Wahnsien fossils come just northwest of the area in red (Chen et al. 2013): .svg/275px-Hubei_in_China_(%2Ball_claims_hatched).svg.png) *This image is copyright of its original author The geographic location of the fossils compared to the modern South China tiger probably confirms that the Wahnsien is the (ancestor of) South China tiger. That could explain the primitive features of the South China tiger as well as the fact that it is quite separated from the rest of the tiger subspecies. The phylogenetic trees published show that the Caspian and Amur are close, and relatively distant from the South China tiger, so I guess the modern Amur isn't a hybrid, at least the ones left in the Russian far east. I think we should now try to define the paleo Amur tiger to figure out its phylogenetic position and whether it even existed or not. The only record I know that goes much past the Driscoll et al. South China boundary is of 2 astragali, a femur, a phalanx, a metatarsal 2, . Hooijer (1947) mentioned that these were recorded by Tscherski (1892). Hooijer stated that one astragalus was larger than his specimen and another smaller, but I only see the measurement of one astragalus in his tables. I think Hooijer typo'd the position of the larger astragalus and put it was Wahnsien tiger instead of Lyakhov tiger. I'll probably never find the original Tscherski document, but here's the citation in case someone can: TSCHERSKI, J. D. 1892. Beschreibung der Sammlung posttertiairer Saugethiere. Mem. Acad. Imp. Sci. St.-Petersbourg, ser. 7, vol. 40, no. 1, pp. 1-511, pls. 1-6. Back to the topic, these fossils were found all the way here: https://en.wikipedia.org/wiki/Bolshoy_Lyakhovsky_Island and also in the Jana river:  *This image is copyright of its original author At first, I doubted Tscherki's confidence that the fossils were tiger. Further reading in Hooijer (1947) states that the Siberian fossils were identical to the Wahnsien ones, the metapodial was extremely robust. To Hooijer, this removes the possibility of Tscherski misidentifying P. spelaea/fossilis specimens as tiger. "Tigers of the World" thinks otherwise, citing Barnett et al. conclusions that two fossils (not Tscherki's specimens) found on Lyakhov island in 1998 were most certainly cave lion based on DNA data. Therefore, we have two possibilities. Tscherki's wrong and we still don't have official proof of a paleo Siberian tiger or the cave lion and tiger coexisted, or almost coexisted chronologically, as in P. spelaea went extinct and P. tigris took over its space soon after. Tscherski's fossils have gone missing or at least are inaccessible like vK's fossils, so DNA testing is out of the question. We can attempt a morphological comparison of Krillinova's far eastern Russian cave lion with the Wahnsien tiger to see which of the aforementioned possibilities is more likely. Tscherski did not publish the greatest width of his astragalus, so we have to assume Hooijer's specimen's proximal width measurements is close enough to Krillinova's greatest width measurement. Hooijer's astragalus measures 61 mm in length and 57 mm in proximal width, robusticity ratio 0.93. Krillinova's astragalus measures 70 mm in length and 57 mm in greatest width, robusticity ratio 0.83. Would you think the ~11% difference is intraspecific or interspecific? The cave lion of NW Germany seem to have astragali of around robustiity ratio of 0.80 as well, taking measurements from Diedrich's photos. Looking at the cave lion astragali, the proximal width prescribed by Hooijer is likely not the greatest width, thus the difference between Tscherski's specimens and cave lions published is likely a bit greater. So let's discuss what exactly is the paleo Amur tiger. What do you guys think about the Tscherski fossils?
Well, I haven't seen any of Tscherski's fossil materials, so I cannot draw any conclusion based on his work for now.
But the new mandible is about 20kya, so it should be prior to the Caspian expansion in the Manchuria, and the mandible looks extremely close to that of the official Wanhsien tiger. So that pretty much gives us an initial impression about the existence of the paleo Amur tiger. Before the human interference, or even before the Toba eruption, there was no natural barrier between the Manchuria and China proper, and I see no reason why tiger shouldn't set its footprint on Manchuria. BTW, the Cave lion was a steppe animal like the modern lion, and I don't think they could live in large number in the Manchurian Taiga forest, so they probably preferred to stay on the northern Siberian steppe. PS, most Siberian Cave lion fossils were discovered in the northern part of Siberia, not Manchuria which is located in the Southeastern part of Siberia.
Here is the Beringian Cave lion, but too much angle distortion from the pic, so it is quite hard to compare with the Wanhsien tiger.
 *This image is copyright of its original author
Based on the mtDNA haplotype, the Amur tiger seems to cluster quite close with the South China tiger.
So from my personal impression, I still doubt that the modern Amur tiger is the pure descendant of the Caspian tiger without mixing with the local paleo Amur tiger.  *This image is copyright of its original author
Also keep in mind that the prehistoric China/Far East was also a paradise for the megafauna, so it should have enough prey base to sustain those mega-sized felines.
But ironically the Beringian Cave lions didn't grow as large as its European cousins, it definitely didn't seize the niche position at the top of the food chain. The best example for comparison is the Smilodon; with Smilodon populator facing almost none true competition, it had supersized itself, but Smilodon fatalis when facing more intense competition from Arctodus Simus and Panthera atrox, the body size was not as thriving as its South American cousins. So the Beringian Cave lions probably faced the same situation here, it didn't grow as large as expected. The prey base in the freezing cold Siberia was probably scarce, and logically the Cave lions should move down to China to search for more prey base, but it didn't succeed either. In comparison, Panthera fossilis (the ancestor of Panthera atrox) had managed to move down to the south when it had set its footprint in the North America. From the above two points, it can be safely assumed that the dominance of the Cave lion probably ended in the Far East. The Siberia and Beringia were too freezing cold to sustain the large prey base, so the solution to become dominant large was to move down to the south where the prey base was larger. Panthera (fossilis) atrox had managed to move down to the south from Alaska to the contiguous United States to search for the large prey base, so the only feasible solution for the Beringian Cave lion is to move down to the south to China for the large prey base. But we know that there is almost no history of the Cave lion in China, and the so-called "Chinese Cave lion" myth was already debunked as Panthera youngi was either a tiger or a sister species of tiger, since a big cat species that originated in the East Asia cannot be more closely related to the lion than to the tiger. The leopard is closer to the lion because they both originated from Africa, so same logic should apply to Panthera tigris and Panthera youngi. In conclusion, I think the presence of the Cave lion was overstated/overrepresented by many, especially from some western experts. I smell the bias when those experts are still so paranoid to insist the old non-logical scientific names like "Panthera leo spelaea", "Panthera leo atrox", "Panthera leo fossilis" when those so-called "subspecies" have many subspecies diversification within itself. I think we should keep our independent study without getting influenced by those biased studies.  *This image is copyright of its original author I was going off these studies, I forgot about Luo et al. Although, maybe certain members of the Amur population may have some link to the Amoy tiger based on Luo et al.'s study now that you point that out. Luo et al.'s specimen are all from the wild (Sikhote-Alin, recent). Where are Driscoll and Xue et al.'s specimens from, the papers aren't clear. I've attached the papers, maybe you guys could look through them and determine the Amur origin, I might be missing/forgetting something? This may be a very like scenario: The Amur tiger faced a serious genetic bottleneck, reducing gene variation. Genetic drift in this small population could have removed all traces of Amoy genes. The Sikhote-Alin specimens sampled by Luo et al. (2004) may have not lost the Amoy genes to drift. Nevertheless, we need to clear up the origin's of the studies in this post to see if this theory is plausible. The method and type of genes sampled could cause the discrepancy, but I think all authors have sampled mostly the same genes. Is there barrier between Driscoll et al.'s proposed line of subspeciation? Subspecies interbreed just fine in captivity, I doubt in the wild tigers would isolate as Driscoll et al. proposed without any geographical barrier.
Well, I would say there are more geographical barriers between the Manchuria and Central Asia than the Manchuria and China proper.
Between the Manchuria and Central Asia, there is a huge Gobi desert, while between the Manchuria and China proper was almost none before the artificial Great Wall. It was much easier for the Pleistocene China tiger to reach Manchuria than the Caspian tiger.
Based on the physical appearance, the pure Caspian tiger looks too shaggy and ruffy, even too much for an Amur tiger.
In term of the appearance, the Amur tiger rather looks more like a crossover between the Caspian tiger and China tiger. The Sumatran tiger as a hybrid of the Indochina/Malay tiger and Sunda tiger is already happening, then why not the hybridization between the Caspian tiger and China tiger?  *This image is copyright of its original author  *This image is copyright of its original author
Since about 2 million years ago, the tiger was already an obligate carnivore that lived in a wide area. Despite its life form, tied to the forest and water, the tiger was spread from Manchuria to Indochina and the entire Sunda shelf. Only the desert areas of the Indian subcontinent, the high mountains of central Asia and the freezing steps of Siberia stopped its expansion.
During all the next thousands of years, the tiger evolved trough evolutionary "waves" that changed the tiger at species level, upgrading it in size, strength and adaptation at several habitats and preys. At about 100,000 years, the tigers existed from the Taiga of Manchuria, the center and south of China, Indochina (up to Burma) and the entire Sunda shelf. Interestingly, while there were some expansion-contraction events in mainland, the Sunda shelf always keep its tigers in one large continental-size land. It was only about 72,000 - 108,000 years ago that the species suffered its worst event, causing almost they entire extinction (only the modern human caused a similar destruction to this species), which was the Topa eruption, no other natural event caused more damage, even the human and lion populations suffered a sever bottleneck. According with the genetic analysis of Luo et al. (2004), only less than 2,000 reproductive females survived the catastrophe, and from this small group all modern tigers evolved, mainland and island included according with the new genetic studies. This group lived in the area of the northern Indochina-south of China jungles, probably the only area that was not too much affected by the climatic disaster. Northern areas like Manchuria probably became in a freezing hell, caused by the clouds of ashes from the Toba eruption and according with Kitchener & Dugmore (2000) and they bio-geographical models, this northern areas were unable to support a tiger population, and it was colonized just after the beginning of the Holocene. Southern areas, like the Sunda shelf, were completely destroyed, maybe some specimens in the eastern part of the Sunda shelf survived, but looking at a map, I found this unlikely now. Those few tigers began a great recovery, just like that in India after 1970, and step by step, recolonized they previous habitat. The planet started its recovery, but several glaciations created climate changes with several dry or wet years. The habitat of all animals, suffered expansions and contractions, but based in fossils and genetic studies, it was not until the upper Pleistocene and early Holocene (12,000 - 20,000 years ago) that the tiger began its colonization of the Caucasus at the west of Asia and the Indian subcontinent. At the same time, the last glaciation ended and the rise of the sea levels separated the Sunda tigers from the mainland tigers, which started they own evolutionary way with the extinction of the larger specimens and the adaptation to a new way of life. In mainland, the tigers began they expansion to the west of Asia via the silk corridor and give origin to the Caspian population (Driscoll et al., 2009), which later returned to the Russian far east and formed a contiguous population that was separated by human intervention at just about 200 years ago. In the south, tigers invaded the Indian subcontinent about 12,000 years ago and created its strongest colony with the best prey base and a great habitat. The population of tigers in the south of China probably moved to the north, but according with genetic studies the modern Amur tiger population don't intermix with this Chinese population. So, in this case, the possible way was that the Amur tigers, after they colonization of the Amur region, moved southern and probably crossed ways with the southern population. Future studies with more specimens from Manchuria and southern areas could provide more evidence, as now it seems that only specimens from the modern Amur tigers at the Sikhote Alin area, were used. Finally, this evolutionary history of the tiger show that they were a contiguous population since about 2 millions years and this was the habitat that they shared until about 75,000 - 108,000 years ago. After the great extinction and the genetic bottleneck caused by the Toba eruption, there is no evidence that other tiger populations (expect, perhaps the eastern areas of the Sunda shelf) survived, so in this context, there were no survival specimens of the Paleo-Amur tiger population, at the north of Manchuria, all eastern Siberia and obviously Beringia. All modern tigers evolved from the last population of Wanshien tigers in the north-Indochina and South of China and the South China tiger was the direct descendent of this group, and according with the new studies of Xue et al. (2015) and Wilting et al. (2015) it was also the ancestor of the modern Sunda tigers. This is the evolutionary history of the tiger, that I can reconstruct using the latest genetic studies.
Then the Panthera spelaea population from the Northeast Asia was also severely affected by the Toba eruption.
Maybe this Cave lion population was the earliest extinct one, much earlier than the European population? Imagine even the main population like tiger has been almost pushed down to the verge of extinction, then I cannot imagine the situation for other trivial populations. Since the Panthera spelaea population was struggling to set its footprint in China, but they could never penetrate beyond Manchuria, so their population was probably much smaller than tiger's. Can you imagine the effect of the Toba eruption to this much smaller population?
So all Manchurian fossils should be pushed back prior to the Toba eruption, and all Manchurian subfossils should belong to the re-colonization era, right?
If the paleo Amur tiger got completely wiped out by the aftermath of the Toba eruption, so did this mean the same for most other carnivorous species? (08-16-2015, 11:01 AM)GrizzlyClaws Wrote: Then the Panthera spelaea population from the Northeast Asia was also severely affected by the Toba eruption. Yes, in fact, Barnett et al. (2009) describe several haplotypes that were extinct in several genetic bottlenecks. One of them separated P. spelaea fossilis from P. spelaea atrox. Other separated the Beringia specimens from those of Europe and other one exterminated the "large sized" specimens and only leave the "smaller" ones. The Toba eruption affected the northern areas with a decrees of the sun light (less heat) and that caused a harder could, probably killing the vegetation and the herbivores. The carnivores were the last to suffer the disaster. |
| Users browsing this thread: |
| 1 Guest(s) |