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Pleistocene Big Cats
Freak Felids - A Discussion of History's Largest Felines
Freak Felids - A Discussion of History's Largest Felines
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Freak Felids - A Discussion of History's Largest Felines
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Here is a huge lower canine tooth of a modern tiger which is about the same size with those large Pleistocene ones.
 *This image is copyright of its original author
Going to have to delay my thoughts again, but here's a study on lion evolution:
A new Amur tiger subfossil from Manchuria; a fragmented upper canine tooth.
 *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
Okay, here we go.
Regarding the Hanko and Korsos (2007) study, it looks like they used the mandible and dentition to phylogenetically organize the species. Issue with this is that they completely overlooked the very real differences in the cranium as presented by Marciszak et al. (2014). So I guess the combination of both these studies would be of better use to classification, and neither is wrong, just not as complete as they would be together. I prefer genetic evidence on top of all this as well, and we don't have study like that yet. On another note, I was reviewing data on cave lion skulls, and the community, including myself, have missed some of the skull issues. P. spelaea are not necessarily superior to P. fossilis in all regards of the skull. Marciszak only focuses on snout width, whereby yes, P. spelaea had wider snouts. I think the difference is statistically just significant (due to the limited sample size of P. fossilis), but I can test it sometime to be sure. Regardless, looks like we've all taken the snout issue and extended it to the rest of the skull. The only complete(ish) skull of P. fossilis is from Mauer, so this will have to be the holotype we'll have to use. This skull, like the other P. fossilis skulls reported, had the narrower snout as we all know. But, the zygomatic width is quite great. This skull measures 442 mm, but the zygomatic width is 300 mm (ZW/GSL = 0.679). This is wider than a good amount of P. spelaea skulls, including the Marciszak et al. (2014). The Mauer skull is proportionately superior in terms of zygomatic width compared to all P. atrox specimens I've read of as well. If we assume that this single skull is not exceptional, we can scratch off the notion of zygomatic inferiority of P. fossilis to the other cave lions. It seems snout width and zygomatic width are not necessarily correlated processes, thus we can't assume P. fossilis' narrower snout equals a narrower skull. Hopefully Argant's Chateau skull measurements get a more thorough publication to see whether the Mauer skull is truly the norm.
This Panthera atrox specimen also has extremely broad snout, but with relatively narrow zygomatic arches.
BTW, I think the largest Panthera spelaea skull is equivalent with the largest Panthera atrox skull.  *This image is copyright of its original author  *This image is copyright of its original author
@GrizzlyClaws, I forgot to get to the other discussion points.
I'd say the combination of distantly related and subspecies simply equals a species. Subspecies is a weird term and maybe is better off dropped, and different populations of a single species be defined as ecotypes. Sotnikova and Foronova, who have done the best analysis of all three of the cave lions, believes each of them are distinct from the lion, so species rather than subspecies. Looking at paleoart as well as fossils, the lion clad probably arrived in waves into Eurasia (Yamaguchi 2004, Sabol 2011a, Sotnikova and Foronova 2014?, Sotnikova and Nikolskyi 2006). This would imply that the three forms are not subspecies if there were replacement events. Now, if the new population waves interbred with each other rather than replaced each other, we have a pandemic species with ecotypes. The latter scenario probably isn't true as the maned lion would have most certainly been contemporary with at least the late P. spelaea population, yet there is no evidence of hybrid traits. I took another look at the Barnett et al. (2009) study, and they have P. atrox closer to P. leo than P. spelaea, opposite to Hanko and Korsos (2007). I wish I had more time at the moment to put everything together, but it seems that genetic, cranial, and mandibular studies aren't in agreement with each other as I do some of my own analysis. P. fossilis has been ignored or passed off as "P. spelaea senior" for quite some time, and I think this is where the problems of contradictory findings are stemming from.
It is now crystal clear that Panthera atrox was definitely born from Panthera fossilis, but Panthera spelaea was not the offspring of Panthera fossilis.
I am just more curious about the origin of Panthera spelaea, if not from Panthera fossilis, where they evolved from?
Most likely the lion mother lineage in Africa. Depending on the climate, immigration was probably blocked for millenia and then reopened. The second wave of immigration brought in a new group of genes that would evolve on a slightly different path.
But they wouldn't interbreed with the modern lions in the wild like the Ngandong tigers and the modern tigers.
I am suspecting they (Fossilis-Atrox-Spelaea) descended from an ancient maneless lion lineage in Africa, and the time split with the modern lion lineage was beyond that of the Ngandong tiger/modern tiger and the Brown bear/Polar bear. The aforementioned two groups all did use to interbreed with each other in the wild. However, the remaining question that baffles me is that even Spelaea and Atrox wouldn't interbreed between themselves, but are they supposed to be more closely related to each other than they do with Leo? Maybe the lion clade group was a very old lineage among the pantherine cats, only the Leo group has appeared fairly recent, but the rest was simply very old, perhaps even older than Tigris.
Maybe the Fossilis-Atrox lineage was the first migration wave out of Africa.
The Spelaea lineage was the second migration group after the later interglacial period. The Leo lineage was the third one to appear, but it is not as widely spread as the previous two. Because of the long glacial period, no genetic exchange for a such long period, that would make Spelaea and Fossilis-Atrox not interbreedable in the wild. According to Guate's info, the Spelaea lineage and the Leo lineage has been split for over 600kya, then the time gap between the Fossilis-Atrox lineage and the Leo lineage could be even greater.
The earliest confirmed P. fossilis is dated to 610 kya from Italy. There is a lion-like specimen dated to 750 kya that may have been P. fossilis as well (Sotnikova and Foronova 2013). Now which group do you P. fossilis came from and when:
"The early history of lion-sized pantherine cats is associated with the African continent where a find of Panthera sp. with features of jaguars, leopards and, to a lesser extent, lions is known from the Pliocene fauna (about 3.5 Ma) of Laetoli site (Hemmer 2011). The specimen from Laetoli was commonly considered as an ancestor of the lion group of pantherine felids (Turner & Antón 1997; Werdelin & Lewis 2005), but Hemmer et al. (2001) consider it as a stem species for the whole group of felids mentioned above. Сurrently, the mandible No. 1273 from the Olduvai upper Bed-II dated as about 1.4–1.2 Ma is believed to be the most ancient form of fossil lions. According to Hemmer et al. (2010), only this specimen actually shares apomorphic dental features with the lion group of felids. Other African finds previously assigned to lion-like felids and known from sediments dated as 1.87–1.12 Ma, can be classified only as the ancestral forms belonging to the lions stem group (Hemmer 2011). (Sotnikova and Foronova 2013)" I'll ignore P. atrox for now as we know it's origin almost for sure. For the remaining three lion species, maybe they all came from unique stem groups if they truly could not interbreed. What is intriguing to me about the cave lion case is that they're seemingly fairly young, despite stem groups appearing as early as 3.5 Ma. Are we missing some of the cave lion fossil record in Europe, or did it take them that long to make the move while it took them no time at all to speciate. The earliest undisputed tigers are from Sangiran, dated to about a millions years old. Not too much younger than the undisputed lion fossil. Though, the cave lion and tiger cases are different due to the lack of spatial isolation in tigers. Asia has been Asia since then, while the union of Africa and Europe were reliant on bridges that likely fluctuated in their availability and quite distant. Searching online, it seems that Africa and Eurasia weren't that well connected. So depending on the temperatures, migrations would really differ between time periods.
I think Panthera fossilis could be descended from Panthera shawi, but this ancient lineage was already extinct in Africa long time ago, probably got replaced by other younger lineages from the lion clade.
http://prehistoric-fauna.com/Panthera-shawi Then you got the point, the time gap between the Spelaea lineage and the Leo lineage could be just as much as that between that of the Ngandong tiger/modern tiger, but the later group had consistent genetic exchange until the disappearance of the Sunda Shelf.
From a Serbian-Croatian website.
http://muzeji-zajedno.hr/hr/portfolio/najveci-spiljski-lavovi-na-svijetu/ And here is the newly discovered tiger-like Ural Cave lion in English. http://www.bradshawfoundation.com/news/index.php?id=Cave-Lions-in-the-Urals |
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