There is a world somewhere between reality and fiction. Although ignored by many, it is very real and so are those living in it. This forum is about the natural world. Here, wild animals will be heard and respected. The forum offers a glimpse into an unknown world as well as a room with a view on the present and the future. Anyone able to speak on behalf of those living in the emerald forest and the deep blue sea is invited to join.
08-30-2014, 08:54 PM( This post was last modified: 08-30-2014, 08:54 PM by tigerluver )
Smilodon
I'll add some more info on Smilodon populator as requested. Last I mentioned was that it was more robust than a bear bone of greater length, that's some serious muscle. So I decided to quickly apply the dimensions of the largest Smilodon specimen (Length = 387.5 mm and HLM = 44.7 mm) to bear regression published in Figuerido et al. (2010). The length formula yielded a mass of 308.7 kg, and the HLM formula a mass of 437.3 kg, averaging 373 kg. These estimates are slightly greater (10-20 kg) than their counterparts based on purely felid data (360 kg).
So at this point, regression has only estimated Smilodon populator at up to 373 kg. Though, there's a bear specimen of similar length and diameter that weighs 440 kg, quite a bit heavier. My explanation for this discrepancy goes down to database. It seems for both bears and cats, using individual species as a datapoints yields underestimates. I've found its more accurate when you use similar sized individual specimens as datapoints. The bear equation also has one major flaw. It uses published average masses of each species rather than the masses of the bone specimens themselves as the "y-value" data, and simply put, such estimates may not be reflective of reality due to this.
Even using tiger data (the thinnest bone yet most dense Pantherine) for Smilodon populator gives an average mass of around 400 kg. The main inhibitor is that bone diameters seem a bit limited in how heavy they can make an animal, add to that Smilodon isn't a long boned animal. In the end, Smilodon is the toughest to estimate, but from what we have, the largest specimen of Smilodon probably weighed up to 440 kg and a weight of 400 kg is just as likely, as the single bear used for comparison may have been somewhat overweight.