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(04-15-2021, 04:24 AM)Balam Wrote: This study hasn't been posted here but a paper that studied the genetic relationship between extinct Pleistocene Patagonian taxa through phylogenetic reconstructions based on mitochondrial DNA concluded that P. o. mesembrina was well within the genetic markers of P. onca, not P. atrox. The likelihood that Chimento and Agnolin's (2017) paper did in fact relate to P. atrox becomes even less substantiated considering that the genetic data from this species is completely lacking from the area. The cave paintings do not depict lion-like creatures (but they do depict spotted felids), and the remains of P. atrox have not been found in other South American or Central American sites southern from Mexico to infer a proper migration, as we do have with other species.
Synergistic roles of climate warming and human occupation in Patagonian megafaunal extinctions during the Last Deglaciation, by Metcalf et al (2016):
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*This image is copyright of its original author
While the modern jaguar forms a monophyletic species, during the Pleistocene P. o. mesembrina could be genetically distinguished as a different subspecies, but not being different enough to be classified as a distinct species altogether. This is why using craniometric data from modern jaguars to rule out the possibility of P. o. mesembrina belonging to a different species is flawed, as the morphology of P. onca would vary from this other subspecies, and the environmental factors that could've contributed to the greater size on the Pleistocene form (such a larger prey availability and biomass during) are not present in the native ranges of extant jaguars. These ecological differences are key in distinguishing the morphological differences the two subspecies depict.
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From the supplementary data:
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*This image is copyright of its original author
If we are to take Chimento and Angolin's work with a degree of plausibility, we should also take into consideration other data that points towards the contrary with stronger DNA samples as opposed to ambiguous skull markers. The idea that P. atrox made it as far as the southern tip of the Patagonia is at best very dubious.
Furthermore, I found their work to lose credibility considering the degree of speculation in which they went to describe the supposed appearance of "P. atrox" based on factors that may have not been related at all, such as fur found on the caves which led them to believe it had a "reddish" coating, something that we do not see i the frozen remains of cave lion cubs.
Sorry I got to this so late. Great paper!
I was comparing the datasets and they are from the same sites mentioned by Chimento and Agnolin (2017). The lack of P. atrox in the same can obviously mean there was no P. atrox or that the frequency of P. atrox was much less and thus it wasn't represented in the small random sample. The sample size is decent at 17.
I could not find it so I was wondering if you were able to find a divergence date between P. onca and P. onca mesembrina in the study? It would be helpful in our reconstructions.
I also have the legends for the excellent comparative photos in Chimento and Agnolin (2017). A is of course the "P. onca mesembrina" skull. B-D is P. leo, E is P. atrox, F and R-Y are extant P. onca, G-H are the fossil P. onca.
Here are the figures again:
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*This image is copyright of its original author
From these comparative photos, Chimento and Agnolin (2017) are correct in the assertion that the incisive foramina of the skull in question are visible in superior view. Extant jaguars do not have this trait and would be solid evidence against the mystery skull being of the extant P. onca form. Even in the fossil P. onca we see the incisive foramina are not visible from the superior view. They also assert that the snout is indistinguishable from P. leo/P. atrox. To me, the rostrum looks more stout then pretty much all the other specimens in the photo except maybe P. spelaea (J) and the fossil P. onca (G and H specifically). Stoutness is however a more jaguar-like trait. I will note that the damage to the snout also makes it harder to ascertain the true stoutness of the rostrum.
It could be fair to say the skull does not group well with comparative specimens as its traits are a unique combination. If "P. onca mesembrina" is a genetically distinct taxon related to extant P. onca, this could make sense. I also want to highlight a new species of P. balamoides in this discussion. To quote, "Panthera balamoides sp. nov. combines characters of smilodontids and Panthera, with more similarities to Panthera onca." This asks the question if the "P. onca mesembrina" skull and P. balamoides are of the same species.
Quote:I was comparing the datasets and they are from the same sites mentioned by Chimento and Agnolin (2017). The lack of P. atrox in the same can obviously mean there was no P. atrox or that the frequency of P. atrox was much less and thus it wasn't represented in the small random sample. The sample size is decent at 17.
Yes, most of the analyzed remains come overwhelmingly from the Mylodon cave which was the site used in Chimento and Agnolin's study. This is really good because it keeps us from inferring if the two genetic data gathered from Metcalf et al. directly correlates with the 2017 paper.
Quote:I could not find it so I was wondering if you were able to find a divergence date between P. onca and P. onca mesembrina in the study? It would be helpful in our reconstructions.
Unfortunately the study didn't mention the divergence date between both subspecies beyond their genetic proximity and how they relate to other pantherines. Perhaps this data will come along in further studies in the future. My guess is that the genetic split between P. onca and P. onca mesembrina would be between 300,000 at most to 150,000, if we use similar evolutionary patterns based on the relationships between the subspecies of P. leo.
Quote:From these comparative photos, Chimento and Agnolin (2017) are correct in the assertion that the incisive foramina of the skull in question are visible in superior view. Extant jaguars do not have this trait and would be solid evidence against the mystery skull being of the extant P. onca form. Even in the fossil P. onca we see the incisive foramina are not visible from the superior view. They also assert that the snout is indistinguishable from P. leo/P. atrox. To me, the rostrum looks more stout then pretty much all the other specimens in the photo except maybe P. spelaea (J) and the fossil P. onca (G and H specifically). Stoutness is however a more jaguar-like trait. I will note that the damage to the snout also makes it harder to ascertain the true stoutness of the rostrum.
I think this area becomes more tricky to assess and where most of the controversy centers around, hence my dissatisfaction with Chimento and Agnolin's work relying almost entirely on ambiguous skull markers to make very bold claims. While the incisive foramina are certainly visible on the P. onca mesembrina skull, the conclusion from the 2017 study concerning the muzzle is in my opinion completely erroneous. As you said the snout in P. onca mesembrina is more stout than in P. leo or P. atrox and almost resembles perfectly the H skull belonging to fossil P. onca. Furthermore, while the skull for P. onca mesembrina is not complete, one can tell from looking at the beginning of the zygoma (and based on the rendition performed in the study itself) that it would've been significantly wider than the zygomatic arches of P. leo and P. atrox. In fact, the difference between P. onca mesembrina and P. atrox is this regard is the most pronounced in the entire sample, while it matches almost perfectly with the remains of fossil P. onca, IMO.
Quote:It could be fair to say the skull does not group well with comparative specimens as its traits are a unique combination. If "P. onca mesembrina" is a genetically distinct taxon related to extant P. onca, this could make sense. I also want to highlight a new species of P. balamoides in this discussion. To quote, "Panthera balamoides sp. nov. combines characters of smilodontids and Panthera, with more similarities to Panthera onca." This asks the question if the "P. onca mesembrina" skull and P. balamoides are of the same species.
Personally, I think that the traits present in the P. onca mesembrina skull align more closely to P. onca than any other pantherine, granted that some differences are appreciated but this could be explained by morphological adaptations that evolved from the basal P. onca as the mitochondrial data has concluded them to be different subspecies.
In regards to "P. balamoides", this was a potential species I was very interested in some time ago as it would've expanded the range of the pantherine felids in the New World considering many people thought this was a different species from P. onca, P. atrox or P. spelaea. However recent studies strongly point towards the possibility that these remain in fact belong to the ursid Arcotherium and it was never a true felid after all. See Yucatán carnivorans shed light on the Great American Biotic Interchange, by Schubert et al. (2019).
Another layer that puts into question the existence of P. atrox in the Patagonia is the lack of cave paintings associated with this taxon in contrast to jaguar paintings. We discussed the ones from the Mylodon cave some time ago, but here's some more from adjacent areas. These paintings were described in the paper La Cueva de los Yaguaretés by Ramirez in 2002 from the Santa Cruz province in the Argentine Patagonia:
Granted that we do not have radiocarbon dating for these specific rock paintings which makes it hard to assess their temporal proximity to P. onca mesembrina and Patagonian post-glacial P. onca, but the depictions are consistent with the cave paintings described by Chimento and Agnolin, with a spotted cat being the common denominator. We know from cave paintings in Europe that local human tribes did not shy away from describing the lion in their art. It is likely that they saw them as extremely important species and held plenty of reverence to them, and we should expect the same phenomenon with human settlements that utilized similar art methods in caves to describe the world around them, as was the case in the Patagonia. Yet we get a complete absence of lion paintings from this region in contrast to the jaguar, this leads me to believe that the relationship between local Patagonian tribes and the jaguar was similar to that of Europeans with cave lions.
We know that Chimento and Agnolin have in their position fur enclaved to a claw and a patch of skin, it would be interesting if they could analyze the genetic composition of those fragments of fur to determine what species they belonged to, rather than liberally guessing. My guess is that they would come back matching Smilodon populator. If further studies like these are not performed by them my suspicions that the conclusions on the supposed presence of P. atrox in the Patagonia by them were simply rushed and may have been driven by bias (wanting to have the presence of P. atrox in South America). I believe that the lack of DNA from P. atrox from Metcalf et al. is a strong enough deterrent to at least put into question the veracity of the claims made in the other paper.
As it is often said extraordinary claims require extraordinary evidence and Chimento and Agnolin have yet to provide us that.
A quick correction on my part, from Paunero's Arte rupestre pleistoceno de Santa Cruz, Patagonia Argentina paper, the dating for the paintings are in fact inferred and the appearance of P. onca mesembrina is deducted:
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"The archaeological record indicates that the first human groups arrived at southern Patagonia at the end of the Pleistocene, these times are characterized by great climatic changes, with fluctuations in flora and extinction processes of fauna (Borrero 2001; Borromei 2003; Páez et al. 1999). If we put aside the dates discussed by the academic community (Goebel et al. 2008; Paunero 2009a; Rubinos Pérez 2003; Waters & Stafford 2007), the evidence indicates that Initial human occupations on the Central Plateau of Santa Cruz were contemporaries of the event known as the Antarctic Reverse Cold Episode (Hajdas et al. 2003; Heusser & Rabassa 1987), related to Younger Dryas from northern hemisphere and that the situation with a trend similar to the current one, it would reflect from 8 ka AP. (McCulloch & Davies 2001; Miotti 2004; Paunero 2009a). Expressed in time ranges and according to knowledge current archaeological, exploratory events and initial colonizing phases
they would be in the range of: 10,000 to 11,200 years 14C BP. (Tables 1-2)."
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"Archaeological, palaeoenvironmental and paleontological evidence shows us that in the Central Plateau, the vegetation was of the herbaceous steppe type, that is, with more abundant and tender grasslands that allowed a greater diversity of animals and the survival of large mammal species adapted to these media and are currently extinct, such as the Hippidion saldiasi (equid), the Lama (Vicugna) gracilis (camelid), Hemiauchenia paradoxus (camelid), Panthera onca mesembrina (large jaguar), the American Rhea (rhea large that persists in the north of Argentina), the Dusicyon avus (species of fox), coexisting with current species, such as Lama Guanicoe (guanaco), Dusicyon griseus (gray fox), Dusicyon culpaeus (red fox), Pterocnemia pennata (choique), Eudromia elegans (martineta) and Félix concolor (puma) (Miotti 2004; Paunero 2009a)."
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"The María Bajo is also present, in this case with another variety of design, the animal, probably a jaguar, can be seen with negatives of close hands, seen from above, with the characteristic spots on its fur, its long tail and the vertebral column, as we can see in Figure 11. A unique and striking case, constitutes the large polychrome feline of cave 6B of El Ceibo, a ranch bordering The Mary, whose image we can see in Figure 12, this has a little more 1.50 m long, it is painted in red with the spots of its fur in black, it also has a bristling back and prominent claw-like legs. Cardich (1979) has interpreted this figure as corresponding to a species of large jaguar currently extinct, Panthera onca mesembrina, which inhabited the region more than 10,000 years ago. In this regard, it should be mentioned that in recent excavations carried out in the La María Quebrada Tunnel Cave, we have recorded a tooth of this species, associated with the buried evidence of the first colonizing human groups in the region."
Good catch on P. balamoides, seems like at least two studies think it's Arctotherium.
Agreed, the next step for the P. atrox in South America idea would be testing one of the remains that are attributed to P. atrox.
We can try to get a rough estimate of the divergence then using the branch lengths. Using the 0.02 scale, the branch length of the P. leo and P. pardus split is about 0.036. The P. onca an P. onca mesembrina split branch length is 0.021. So the genetic gap between P.leo/P. pardus is 1.71 times the gap between P. onca/P. onca mesembrina. In other words P. onca and P. onca mesembrina are 1.71 times more closely related than P. leo/P. pardus. We then have to find a way to calibrate this change to time to find a rate of change. I found a study that estimates the divergence of P. leo/P. pardus at 4.35 MYA. So the rate of change over time would be 4.35 MYA divided by 0.036, equaling 121.1 MYA/1 unit of change. Using stoichiometry, P. onca and P. onca mesembrina would have diverged 2.54 MYA. This is around the divergence of P. leo and the cave lions. By this, P. onca mesembrina would be its own species but most closely related to the jaguar. Molecular dating is fickle however and the confidence intervals are wide.
Evidence into the possibility that P. onca mesembrina is its own taxon is that despite the fossils being around only 10 kya old, they are distinct from extant P. onca. This would mean there was no interbreeding which can define speciation depending on the timespan.
This could explain why there is a large gap in size noted by Chimento and Agnolin (2017) between P. onca mesembrina and fossil P. onca. They were indeed distinct populations and perhaps size served as a sympatric barrier.
I wonder if the cave paintings simplify rosettes into spots or if they were accurate. They probably are simplified but if not could show a difference in the coat pattern of P. onca? mesembrina.
It is still possible P. atrox existed in the region prior to the time of these cave paintings. However, I am leaning toward digging into P. onca? mesembrina more.
Good catch on P. balamoides, seems like at least two studies think it's Arctotherium.
Agreed, the next step for the P. atrox in South America idea would be testing one of the remains that are attributed to P. atrox.
We can try to get a rough estimate of the divergence then using the branch lengths. Using the 0.02 scale, the branch length of the P. leo and P. pardus split is about 0.036. The P. onca an P. onca mesembrina split branch length is 0.021. So the genetic gap between P.leo/P. pardus is 1.71 times the gap between P. onca/P. onca mesembrina. In other words P. onca and P. onca mesembrina are 1.71 times more closely related than P. leo/P. pardus. We then have to find a way to calibrate this change to time to find a rate of change. I found a study that estimates the divergence of P. leo/P. pardus at 4.35 MYA. So the rate of change over time would be 4.35 MYA divided by 0.036, equaling 121.1 MYA/1 unit of change. Using stoichiometry, P. onca and P. onca mesembrina would have diverged 2.54 MYA. This is around the divergence of P. leo and the cave lions. By this, P. onca mesembrina would be its own species but most closely related to the jaguar. Molecular dating is fickle however and the confidence intervals are wide.
Evidence into the possibility that P. onca mesembrina is its own taxon is that despite the fossils being around only 10 kya old, they are distinct from extant P. onca. This would mean there was no interbreeding which can define speciation depending on the timespan.
This could explain why there is a large gap in size noted by Chimento and Agnolin (2017) between P. onca mesembrina and fossil P. onca. They were indeed distinct populations and perhaps size served as a sympatric barrier.
I wonder if the cave paintings simplify rosettes into spots or if they were accurate. They probably are simplified but if not could show a difference in the coat pattern of P. onca? mesembrina.
It is still possible P. atrox existed in the region prior to the time of these cave paintings. However, I am leaning toward digging more into P. onca? mesembrina more.
Really good points! Certainly, the idea of P. onca mesembrina being in fact P. mesembrina is an interesting proposition that will require more data and genetic studies to further corroborate but it seems well within the realm of possibilities to me. I still find the likelihood of P. atrox making it so far south into the continent unlikely and believe that the remains studied on the 2017 paper belong to a P. onca ecotype or close relative. What is interesting about this are the "mini-clades" that formed within the genus Panthera, primarily three different clades that comprise closely related species: the lion, jaguar, and tiger clades, in parallel to the Neofelis sp. analogy I've done in the past.
Speciation is a complex subject that is constantly changing and we should always be open to new information that can allow us to have a better understanding of the phylogenetic relationships between species. Jaguars have been relatively understudied in comparison to their other pantherine cousins so further future studies on them and their prehistoric relatives will be very interesting to go over they get published in the future. What is clear to me is that jaguar morphology has always been volatile in relation to the environments they inhabited which is depicted on their diverse biomass, with some pretty drastic size difference among extant jaguars, and even greater discrepancies on absolute values among extinct forms.
Panthera onca augusta (Leidy)
A large feline is represented by various skull fragments and limb elements in the collection of the Bureau of Economic Geology, University of Texas (BEG-UT 40673-45 to 40673-80). This material differs from pumas and is like the modern jaguar in the following characters: the mastoid is larger, especially in its outward projection; the bulla is less elongate and not ridged anteroposteriorly; the anterointernal process of the entotympanic is flattened; and the fringe of the ectotympanic extends farther forward. The juncture of the bicipital crest and the deltoid ridge is lower on the humerus shaft (about midlength). All of these characters are shared with P. atrox but our material is below the size range for that species; the ulna olecranon in our specimen rises higher above the sigmoid notch and is straighter along its posterior edge. There is one character, however, that does not fit the published data on jaguars; p4 is smaller relative to M1 than in P. atrox and modern jaguars. This difference is not considered important enough to outweigh the many other totally jaguar-like characters, however, and reference to the living species is made with confidence. Simpson (1941), when reviewing the large Pleistocene felines from North America, demonstrated that much of the material is indistinguishable from the living species, P. onca. Like the Laubach Cave specimen and one described by Semkem (1961) from Longhorn Cavern in Texas, most of Simpson's specimens are slightly larger than modern specimens of P. onca milleri, the subspecies currently living closest to the United States, but probably within the size range of P. onca palustrus of South America. Even so, Simpson felt it convenient and justifiable to refer these large jaguars to an extinct race, P. o. augusta (Leidy).
10-16-2023, 04:21 AM( This post was last modified: 10-19-2023, 06:30 PM by Balam )
A massive male Patagonian panther (Panthera onca mesembrina) walks through the open steppe as a herd of guanacos watches wearily from the distance. Chile, 20kya.
I made this image with the help of DALL-E 3:
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This image shows a huge 200+ kg male P. onca mesembrina. Per the remains and cave depictions we have of this prehistoric jaguar, we know it had a reddish fur, the rosettes were probably more sparsely located across the body and lighter in coloration. It has the characteristic hyper-robust built of a jaguar with a thick winter coating. The body proportions are less stout as this subspecies never went through the dwarfing phase of tropical jaguars. It has a round and wide skull like other jaguar subspecies.
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I tried looking on other scientific journal sites where the paper was published but the legend for those charts is not there either. The only explanation available is the fragmented skull which has been discussed before and I'm sure you're aware of:
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Looking at the proportions of the skulls from the supplemented charts, my guess is that it is a collection of Pantherine skull from Puma, P. leo, tigris, onca, atrox and perhaps spelaea as well, used to determine the anatomical differences mentioned in the paper to substantiate the proximity in traits the aforementioned skull had with P. leo and P. atrox, rather than P. onca. What do you think?
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*This image is copyright of its original author
@tigerluver, where did you find the legend for these figures?
