(07-06-2018, 09:06 AM)tigerluver Wrote: @Smilodon-Rex , you mention a giant (Amphi)machairodus giganteus skull. I have read of a skull of the species being referred to as giant but do not recall it being 460 mm. Here is a link to the 415 mm skull I refer to. Would you have the source to share?

(07-06-2018, 09:06 AM)tigerluver Wrote: @Smilodon-Rex , you mention a giant (Amphi)machairodus giganteus skull. I have read of a skull of the species being referred to as giant but do not recall it being 460 mm. Here is a link to the 415 mm skull I refer to. Would you have the source to share?

(05-24-2018, 04:36 AM)tigerluver Wrote: Maybe a difference in the carnivora guild between the Americas kept S. fatalis smaller from the start? Or perhaps some type of social structure?

Panthera atrox probably arrived onto the Americas as massive as it was from the start because it was closely related to or simply an offshoot of P. fossilis. Considering the disappearance date of P. fossilis and relationship to P. atrox, P. atrox probably arrived onto America much earlier than fossil record shows. Thus, the S. fatalis and P. atrox interactions and thus evolutionary forces they had on each other probably started earlier too. 

Considering how the fossils recorded are rather recent, perhaps P. atrox being giant it was from its appearance inhibited S. fatalis slow progression to a larger size like its cousin in the south and thus by the end of its time, S. fatalis found it better to stop increasing in size and let P. atrox have the superpredator niche.

(05-20-2018, 09:25 PM)GrizzlyClaws Wrote: Since Smilodon fatalis and Smilodon populator were likely derived from the more primitive Smilodon gracilis, and ironically both species had predated Panthera atrox in the history of America.

But why Smilodon fatalis just let the newly arrived Panthera atrox seized the niche position as the top predator in its domain, while Smilodon populator remained occupying that position?

Maybe fatalis was positioned to be the second fiddle, while populator chose to evolve as the apex predator?

(07-06-2018, 07:47 AM)Smilodon-Rex Wrote:

*This image is copyright of its original author

*This image is copyright of its original author

Giants of Ice Age——American Lion＆Smilodon designed by myself
 @GrizzlyClaws ,  Smilodon populator's size may just equivalent to modern big tiger's subspecies, however, they still heavier than modern lions and tigers, and can also grow into 400 kg. Moreover, Smilodons have the more powerful body than modern lions and tigers since they born.
 American Lions also have the more powerful body than modern felines too, be different from Smilodons, American Lions are taller and their heads are bigger. 
    Here are the bodysize's range of few prehistoric big cats:
Smilodon populator——from 420 to 430 kg
Amphimachairodus giganteus——it may the biggest machairodontinae in history, according to the estimates of 460 mm skull, the weight limit may achieves  450 kg
American lion——from 450 to 465 kg  
Eurasia Cave lion——from 430 to 450 kg
Mosbach lion——from 450 to 493 kg
Ngandong tiger——from 350 to 370 kg
Natodomeri lion——from 350 to 370kg

(08-31-2018, 07:01 AM)johnny rex Wrote: @GuateGojira also mention that the largest lion skull that he know measured 432 mm (17 in) in greatest length and 280 mm in zygomatic wide (11.0625 in). He said this is also in Rowland Ward’s Records of Big Game of 1914.

(08-31-2018, 06:55 AM)johnny rex Wrote: Any thoughts about the measurements above, @peter ?

(08-31-2018, 01:26 PM)peter Wrote:

(08-31-2018, 06:55 AM)johnny rex Wrote: Any thoughts about the measurements above, @peter ?

The longest lion skull I saw (just over 16 inches) belonged to a male captured in what was known as Abessynia a long time ago. He ended up in Artis zoo (Amsterdam). I measured his skull in the former Zoological Museum of Amsterdam (ZMA). My guess is it now is in the Naturalis Natural History Museum in Leiden. 

Although a few others just exceeded 15 inches, skulls of wild African males averaged about 14 inches. 

I don't know what to think of the 18-inch skull topping the list you posted. 

Lions have longer skulls than tigers. It's very likely that exceptional lion skulls are a bit longer than exceptional tiger skulls. If a captive male Amur tiger can reach about 17 inches in greatest total length (referring to the skull of the young adult male Amur tiger from Koln), a male lion also can.