Comparing Cats: A Discussion of Similarities & Differences

[dominusforti]

(03-17-2022, 03:59 AM)Pckts Wrote:

(03-17-2022, 02:59 AM)dominusforti Wrote: I feel like there is a lot of bias going on here...on both sides. Nevertheless, I agree with @SpinoRex in that lions and tigers are very similar, they belong to a rather osteologically homogeneous group (Panthera) and are within that group the most similar species to each other.

But, for the clavicles, first I will say that the difference is obviously statistically significant, all the other felids group together (with some variation) but the African lion and, crucially, the American lion, stand out as having significantly higher values. I'm not insinuating this makes them stronger but it's not worth debating the obvious truth that the difference is real and not caused by some kind of sampling error.

Fwiw, larger and more recurved claviculae are typically found in arboreal species, whereas terrestrial (especially cursorial) species tend to have reduced clavicles or lack them altogether.

So, the advantage would be something that helps scansorial taxa use their forelimbs to climb. The cost is a little less clear but it definitely isn't helping in the lion's cursorial habits. Therefore the adaptive reason would need to be something else. Possibly allowing lions to compensate for their general trend toward cursoriality while still needing to stalk, accelerate, and grapple large prey like the other pantherine felids.

How can there be no sampling error when you're comparing all females to mostly males and on top of that, one of the smallest sub species of Tigers, one being a stillborn as well.

I mean, in the nicest way possible but did you read through the paper? Because it explains why sexual dimorphism cannot explain the marked difference not just between lions and tigers but between both types of lion (two different species belonging to the lion ecomorph and lineage) and all other forms of felid. In a principal components analysis, "the lions [which they describe as the large, robust clavicular morph] and large fossil morphs clearlt separate themselves from the other felids, with the tigers overlapping with, although falling toward the large-end of the rest of the cats."

The difference between lions and all other felids was diagnostic enough for the researchers to deduce that large fossil morph had to be Panthera atrox, due to its lion-like values. P. leo plots closer to the giant P. atrox than it does with P. tigris, which overlaps with the other smaller felids and remains identifiably separate from P. leo on PC 1. The difference therefore seems much too significant to attribute to sexual dimorphism and, even to entertain that notion for a moment, the felids for which males and females were included did exhibit strong sex-based differences, and the single lioness clavicle is just as distinct from the tiger sample as the male lions were. Reply