Ancient Jaguars

[Balam]

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):

*This image is copyright of its original author

*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 conclude that P. o. mesembrina belonged 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.

*This image is copyright of its original author

From the supplementary data:

*This image is copyright of its original author

*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. Reply