Skulls, Skeletons, Canines & Claws

[tigerluver]

(07-21-2021, 11:14 PM)GrizzlyClaws Wrote:

(07-21-2021, 07:39 PM)tigerluver Wrote:

(07-21-2021, 08:48 AM)GrizzlyClaws Wrote: Some Eastern Cave lions were absolutely huge, and maybe they were smaller on average than the Western Cave lions, but those top notch specimens were just as large as the largest Western Cave lions.

And they did have proportionally longer/thinner canine teeth.

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

Monstrous specimens!

Do you know the alleged localities? What would you say the length measurements of the specimens are?

The giant jaw looks Romanian in both size and preservation.

The skull has other peculiarities. I have never seen a truly complete carnivore skull from Eurasia on the fossil market, they are all restored or composite to increase the price. Maybe it's just the specimen, but the skull shows some oddities like a very short muzzle (could be camera angle), the posterior edge of the occiput goes very far past the condyles, the posterior arch is very narrow, there is plastering on the anterior end of the left hemimandible, the mandible is glossy and uniform in color while the skull is dull in color, and parts of the skull (like the occiput and area anterior to it) are different colors (which gives some concern for restoration work).

These Cave lion fossils were labelled as the Beringian subspecies from the eastern Siberia.

These guys seem to be about in the same league with the giant Kahayan tiger, and they can be told apart from the European Cave lions with their relatively long canine teeth.

The mandible seems to have a very robust canine. Despite being a bit shorter than P. atrox largest 309 mm (canine AP ~30 mm) and 318 mm (canine AP ~33.5 mm) mandibles, it is wider in the AP diameter (34 mm purported from that photo). For unit height, it is likely more robust than the Kahayan canine (that tiger has more of a sabertooth style canine) but vertical quite a bit shorter. Comparing the length, the horizontal ramus of this cave lion seems about the same to a slight bit longer because the vertical ramus and associated masseteric fossa are shorter than expected for a cave lion of this stature. The horizontal ramus of this cave lion is very robust and tall, probably quite a bit moreso than any tiger including the Kahayan mandible. This is a unique cave lion trait. P. leo for comparison have thin mandibles, especially anteriorly. The vertical ramus however seem short and significantly shorter than the Kahayan tiger's projection. From the point of the anterior canine to the division of the inferior contour of the masseteric fossa, the Kahayan mandible is 5-10% longer and seems to indicate it had more masseteric fossa for its jaw. I wonder if this is not a Late Pleistocene animal as the tall horizontal ramus but short vertical ramus indicate less muscle attachment and weaker bite force, which could correlate with the thinner skulls of P. fossilis.

Now I have a question to see if anyone has any hypotheses. Why do wide skulled cats have shorter, less robust horizontal rami of the mandible? For instance, P. fossilis has a narrower skull than P. spelaea but has a very tall and robust horizontal ramus. The Ngandong tiger skull is narrow but the Watualang mandible is proportionately more robust in the horizontal ramus than any extant tiger. The widest tiger skull I have measured was from Malaysia, with a length of about 320 mm but was extremely wide for its length at 245 mm. Its mandible is just like the Kahayan tiger's, short in the horizontal ramus, but with a tall, deep, and long vertical ramus and associated masseteric fossa. These observations show that the wide skulls with less robust horizontal rami have greater surface area for musculature. Conversely, the cats with tall horizontal rami have much less surface area for musculature. 

As an aside, the cave lion skull still has some concern given the fossil market. I hope it is not a composite and the stuck on a canine (and maybe maxilla too) of a different animal onto it making the canine seem thin. Full skull finds are nearly impossible. Reply