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Pleistocene Big Cats
The Cave Lion (Panthera spelaea and Panthera fossilis)
The Cave Lion (Panthera spelaea and Panthera fossilis)
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The Cave Lion (Panthera spelaea and Panthera fossilis)
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 (02-17-2019, 06:39 AM)Ghari Sher Wrote:(02-10-2019, 07:24 AM)tigerluver Wrote: A new study was published recently identifying P. atrox, S. fatalis, and P. spelaea in southern Canada not to far from the US border. While it is expected for P. atrox and S. fatalis to be found this far south, the same cannot be said about P. spelaea. The authors' reasoning was that the ulna was smaller than that of the La Brea tarpit P. atrox and the "posterior edge of the shaft appears to be straighter in lateral view" as compared to P. atrox. The specimen was previously assigned to S. fatalis. Thanks for the reminder, I took a look at Barnett et al. (2009) and did notice that that work only finds the Alaskan lion to be P. spelaea so Harington's ulna would be reclassified to P. spelaea by this regard. Nonetheless, that goes back to the point that an ulna (an incomplete one at that) has too much variation to distinguish between relatively near identical species. The Barnett et al. (2009) also did not find any P. spelaea that close to the US-Canada border. It does have to be acknowledged that the sample size of Alaskan and southern Canadian fossils from the study is quite small, so the allopatry found by the study may not necessarily be reality. For instance, we know now S. fatalis existed deep in S. populator territory.   *This image is copyright of its original author  *This image is copyright of its original author Discoveries of huge cave lions in cave Imanai (Ural) inspired Russian paleo-painter Velizar Simeonovski to create painting "Short Triumph". He describes the scene: "Early evening in March. Small group of hunters, late neandertals just killed small cave bear (Ursus rossicus), it was easy victim since the bear was exsausted by long hibernation": https://www.oblgazeta.ru/news/15525/  *This image is copyright of its original author
Waveriders' study about the Cave lions; Panthera fossilis max skull up to 21 inches, and Panthera spelaea up to 20 inches.
 *This image is copyright of its original author
 (03-04-2019, 02:05 AM)GrizzlyClaws Wrote: Waveriders' study about the Cave lions; Panthera fossilis max skull up to 21 inches, and Panthera spelaea up to 20 inches. (03-04-2019, 04:47 AM)epaiva Wrote:(03-04-2019, 02:05 AM)GrizzlyClaws Wrote: Waveriders' study about the Cave lions; Panthera fossilis max skull up to 21 inches, and Panthera spelaea up to 20 inches. IMO, it was probably a little bit inflated. Since this fragmented humerus was probably the largest documented fossil for any Pleistocene lion, definitely outsized the 192 mm MT3 which was used to predict the largest specimen by Waveriders, and according to @tigerluver, this humerus could probably couple with a 500 mm skull max. So the largest Pleistocene lion skull probably measured up to 500 mm.  *This image is copyright of its original author
With the chart of the M1 length of the lions of Imani cave, we may be able to estimate the length of this mandible:
 *This image is copyright of its original author The largest M1 from the following chart is 33.4 mm:  *This image is copyright of its original author From the photo, the mandible length to M1 length ratio is just about 9. If we assume that mandible is the owner of the largest M1 from the above chart, it would measure about 300 mm as is. The complete mandible (incisors to condyloid process) is about 5% more so if complete it would have measured about 315 mm. The M1 length of 33.4 mm is also comparable to the 309.5 mm (M1 33.4 mm, GSL 458 mm) and 318 mm (M1 33.9 mm 467.5 mm) P. atrox specimens. The other teeth grouped by the authors to be male should also be from mandibles no less than 280 mm. The faunal level of these specimens was dated to the middle of the Late Pleistocene, so at least by temporal classification, these would be considered P. spelaea. A morphological analysis would help to classify these specimens with greater confidence. Assuming these are what is considered P. spelaea, there is no reason to believe that the P. atrox of Rancho La Brea were any larger. Remember, like in modern big cats, there are clinal variations in size. The P. spelaea that were historically considered to be not as large may have simply represented a smaller sized clinal variation. Even in Europe, specimens comparable to the biggest of the P. atrox existed. From Alan Stout, here is a specimen a bit shorter than 300 mm from Romania (link):  *This image is copyright of its original author All in all, post-cranial remains are skewed toward certain populations, perhaps falsely giving the perception of smaller size in P. spelaea. Perhaps the species underwent fluctuations in size through time as well. (03-14-2019, 05:46 AM)tigerluver Wrote: With the chart of the M1 length of the lions of Imani cave, we may be able to estimate the length of this mandible: Is there any contemporary fossil nearby that has been documented to be larger than the giant 475 mm skull from Mokhnevskaya cave? Compared to the giant humerus of Panthera fossilis from Central Europe to the giant tiger mandible, which specimen got an upper hand?  (03-04-2019, 02:05 AM)GrizzlyClaws Wrote: Waveriders' study about the Cave lions; Panthera fossilis max skull up to 21 inches, and Panthera spelaea up to 20 inches. Talking about prehistoric tigers and cave lions, I noticed something about some tiger fossils in a way that is quite similar to fossils of the Upper Pleistocene Eurasian cave lion (Panthera spelaea or Panthera leo spelaea) in the Spanish cave of La Garma, which I mentioned here (https://wildfact.com/forum/topic-tigers-...1#pid88981). The tiger fossils are 2 articulated phalanx bones, possibly from the same toe, besides a distal segment of a basal phalanx (ICWM-2376) of the 4th or 5th digit of the manus or pes, which were excavated amidst an assemblage of other animal bones and stone tools in Ille Cave near the village of New Ibajay in the province of El Nido, in the northern part of the Philippine island of Palawan. One bone (IV-1998-P-38239) was a full basal phalanx of the second digit of the left manus, and the other (IV-1998-P-38238) was the distal portion of a subterminal phalanx of the same digit and manus. With the former bone having a greatest length of 46.44 mm (1.828 inches), and the latter having a medio-lateral width of the distal end of 16.04 mm (0.631 inches), for example, their measurements were similar to those of Malayan and Indian tigers. The other fossils were identified as being of long-tailed macaques, deer, bearded pigs, small mammals, lizards, snakes and turtles: https://www.sciencedirect.com/science/article/pii/S0031018208002113?via%3Dihub *This image is copyright of its original author Ille Cave, north Palawan: https://pia-journal.co.uk/articles/10.5334/pia.308/  *This image is copyright of its original author  *This image is copyright of its original author Piper et al.: https://www.sciencedirect.com/science/article/pii/S0031018208002113?via%3Dihub *This image is copyright of its original author The case of the 2 Palawanese tiger toe-bones being found in Ille Cave amongst the fossils of other animals, which were likely collected by humans (judging from the stone tools found in the cave, besides the evidence for cuts on the bones, and the use of fire), somewhat resembles the case of 9 claws or toe-bones of Upper Pleistocene Eurasian cave lions (Panthera spelaea or Panthera leo spelaea) from roughly the same period (the Upper Paleolithic or Pleistocene, around 16,000 years ago), which were found in La Garma Cave in Spain, amongst the fossils of other animals, including horses and goats, and were likely to have been used by early humans for rituals, and it is not like cave lions did not occur in the Iberian Peninsula: https://www.nytimes.com/2016/10/27/science/cave-lion-pelts-caverns.html The area within the La Garma cave system where the cave lion claws were found, credit: Pedro Saura  *This image is copyright of its original author 8 of the 9 cave lion toe bones found in the Upper Paleolithic cave site, credit: Marian Cueto  *This image is copyright of its original author
Maybe the convergent evolution was occurred among all Pleistocene big cats?
Since the Pleistocene lions were less social then the modern African lions; thus, they were probably more convergent with Pleistocene tigers as well.
Incomplete skeleton known as Arrikrutz it was found by Iñaki Subeldia in Spain in 1966, they estimate it weighted about 250 kilograms
Credit to zoologiamania  *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author
Posted this on the American lion thread but it's relevant here too. American lion and cave lion fossil remains are found together in the same Canadian locality. This is the first time that the two species have been found to be sympatric.
"Fossils found in Medicine Hat, Alberta change that. The fossils themselves were collected in the 1960s along the South Saskatchewan River, but, as Reynolds and coauthors note, the cat bones that were plucked up were never properly described. Upon examination, the cat remains in this one place represent several species – lynx, the American lion Panthera atrox, the cave lion Panthera spelaea, and Smilodon fatalis. (The discovery of the American lion and cave lion in the same place is also noteworthy, not just for expanding the range of cave lions into southern Alberta but also driving the point that paleontologists should carefully evaluate their appraisal of lion remains in North America given there are two species in play.)" https://blogs.scientificamerican.com/laelaps/canada-gets-its-first-smilodon/ (04-21-2020, 08:37 PM)OncaAtrox Wrote: Posted this on the American lion thread but it's relevant here too. American lion and cave lion fossil remains are found together in the same Canadian locality. This is the first time that the two species have been found to be sympatric. Discussed a few posts above, but the basis for the identification of P. spelaea is rather shaky. Copy and pasting from above, the authors' reasoning was that the ulna was smaller than that of the La Brea tarpit P. atrox and the "posterior edge of the shaft appears to be straighter in lateral view" as compared to P. atrox. The size argument is weak as there is a lot of variation within a population. The contour argument does not hold up too well as in both P. spelaea and P. atrox we see straight and curved ulna. We'd need a skull or DNA/protein analysis to confirm the validity of this claim.
Turns out that the cave lion diversification from the modern lion happened later than previously thought, with some researches considering subspecies of Panthera leo (in case there remained any doubts on their positions as true lions), but this is debatable.
Lions are one of the world’s most iconic megafauna, yet little is known about their temporal and spatial demographic history and population differentiation. We analyzed a genomic dataset of 20 specimens: two ca. 30,000-y-old cave lions (Panthera leo spelaea), 12 historic lions (Panthera leo leo/Panthera leo melanochaita) that lived between the 15th and 20th centuries outside the current geographic distribution of lions, and 6 present-day lions from Africa and India. We found that cave and modern lions shared an ancestor ca. 500,000 y ago and that the 2 lineages likely did not hybridize following their divergence. Within modern lions, we found 2 main lineages that diverged ca. 70,000 y ago, with clear evidence of subsequent gene flow. Our data also reveal a nearly complete absence of genetic diversity within Indian lions, probably due to well-documented extremely low effective population sizes in the recent past. Our results contribute toward the understanding of the evolutionary history of lions and complement conservation efforts to protect the diversity of this vulnerable species. Previous studies based on partial fragments of the mitochondrial genome have estimated that cave and modern lions diverged ca. 500,000 y ago, using the appearance in the fossil record of the ancestral cave lion Panthera fossilis (5, 6). More recently, the divergence time was estimated to be 1.89 million years ago using full mitochondrial sequences and multiple fossil constraints (8). To investigate these discrepancies among estimates, and to fully resolve the position of cave lions in the phylogeny, we applied three independent methods that leverage the power of whole-genome sequences and do not rely on fossil record calibrations to estimate the divergence time between cave and modern lions. First, we investigated the split time between the ancestral populations by estimating the probability F (Aderived|Bheterozygous) (17) of an individual A (such as the Siberian or Yukon cave lion) carrying a derived allele discovered as a heterozygote in a modern lion individual B. This summary statistic was then used to estimate the divergence time of the cave lion lineage given a model of population history in modern lions inferred using the pairwise sequential Markovian coalescent (PSMC) (18). We estimated that F(Cave lion|Modern lion) averaged at ∼0.15 (Fig. 2A), meaning that cave lions carry the derived allele in ∼15% of the heterozygous sites detected in modern lions (14.7 to 16.4%; SI Appendix, Table S2). From a simulation of the expected distribution pattern of F(Cave lion|Modern lion), given the population history of modern lions, a mutation rate (µ) of 4.5 × 10−9 per generation (11), and a generation time of 5 y (19),  *This image is copyright of its original author We further explored the divergence time between cave and modern lions by exploiting the fact that the Siberian cave lion was a male (SI Appendix, Table S5). Male X chromosomes can be used to construct synthetic pseudodiploid genomes and estimate rates of coalescence between their ancestral populations. Since the effective population size (Ne) is inversely correlated with the amount of coalescing events occurring at a particular point in time, the Ne inferred from a pseudodiploid chromosome of two diverged populations should suddenly increase around the time of their divergence, as no coalescent events can happen after this estimated time assuming reproductive isolation occurred after the split. Indeed, we inferred from the PSMC of cave and each modern lion combined X chromosomes that there was a sharp increase in Ne to an unmeasurably large size ca. 495,000 y ago (Fig. 2B; 460,000 to 578,000 y ago, SI Appendix, Table S6). However, we caution that there may be added uncertainty around this estimate due to the low depth of coverage in the X-chromosome of the Siberian cave lion (1.96-fold, SI Appendix, Table S5). We also assessed estimates of sequence divergence (dxy), which should be directly related to the split time (T) and the Ne of the common ancestor (Neanc) (dxy = 2Tµ + 4Nanc µ). We found that the mismatch rate between the Siberian cave lion and modern lions using only transversions was an average dxy = 0.00067 (SI Appendix, Fig. S6). Assuming that µ = 4.5 × 10−9 per generation (11), a transition/transversion ratio of 1.9 (SI section 4), a branch shortening in the Siberian cave lion of 6,000 generations (SI Appendix, Table S1) and Neanc of 55,000 individuals (Fig. 3A), we obtained a split time of ca. 108,000 generations [540,000 y assuming a generation time of 5 y (19)]. Given the general congruence among our estimates, we conclude that the most likely split time between cave and modern lions is ca. 500,000 y ago. This estimate is also remarkably consistent with the early Middle Pleistocene appearance of P. fossilis in the European fossil record (5). Full study: https://www.pnas.org/content/early/2020/04/28/1919423117 |
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