Andrewsarchus mongoliensis vs. Sarkastodon mongoliensis

[Deleted]

I agree, Andrew wins easily.

[dinosauria101]

I'll give this to Andrewsarchus, it's larger and has a much deadlier bite.

[Infinity Blade]

Regarding grappling abilities on Sarkastodon, one of its closest relatives and morphologically very similar, Patriofelis, lacks retractable claws and in fact its ungals are proportionally small and straight, indicating that "they entirely lacked the grasping and tearing power developed in Felis" according to Osborn, Gunnel & Gingerich (1991) says that the features of the radius indicate that Dipsalidictis was capable of supination and pronation to at least some degree but Oxyaena's was designed more for weight bearing and was less mobile at the wrist. Oxyena is considered ancestral to Patriofelis and much smaller so we can expect to the mobility to diminish even further in Patriofelis and more so in Sarkastodon which was at least 40% larger still than the largest Patriofelis.

Turns out this isn't entirely true. The wrists of Patriofelis were actually more flexible than found in modern carnivorans, and certainly allowed pronation and supination. Additionally, the elbow joint was flexible and the forelimbs show powerful muscle attachment sites, suggesting Patriofelis did, in fact, grapple with prey (Kort, 2019).

The forearm shows well developed sites for muscle attachment. The large deltopectoral crest provides the insertion point for a large deltoid and pectoralis major, muscles involved in adduction and abduction and flexion and extension of the arm. The wide capitulum would have allowed supination and pronation in the forearm and separate lunate and scaphoid indicate a more flexible wrist than found in modern carnivorans (Savage, 1977). Patriofelis was likely plantigrade based on these features, as well as relatively short metacarpals and the splayed angle of the metacarpal heads (Figure 9).

Patriofelis characteristics most closely match those of modern ambush predators. Ambush predators hide from prey and chase in a short burst compared with pursuit predators which chase their prey over long distances (Van Valkenburgh, 1985). Modern ambush predators also rely on grappling to bring down prey rather than exhaustion through long chases (Janis and Figueirido, 2014). While its short limbs and inflexible spine would have inhibited some movement, large sites for muscle attachment and robust bones would have made Patriofelis strong and tougher to injure than more gracile predators. In Patriofelis, robust forelimbs with large sites for muscle attachment and joints that allow for abduction is associated grappling prey (Janis and Figueirido, 2014). The shortened limbs and large muscle attachment site also imply Patriofelis was capable of powerful short bursts of movement, but not sustained high-speed locomotion. Thus, it is possible that the inflexible lumbar in Patriofelis resisted torsion and breakage in the spine while fighting prey or possibly other predators rather than stabilizing the back for long distance locomotion as seen in modern ungulates.

Patriofelis has characteristics of a large, terrestrial ambush predator with no specializations for arboreal or semiaquatic locomotion. The large size, short limbs, and lack of elongated or curved claws would have restricted arboreal locomotion. Inflexible lumbar, and limbs inefficiently proportioned for drag in the water show a lack of specialization towards semiaquatic locomotion. Large attachment sites for muscles in the forelimb and a flexible elbow joint would have allowed Patriofelis to grapple with large prey, a feature many extant ambush predators have (Janis and Figueirido, 2014). Flexible forelimb and hindlimbs would have also allowed for navigation through the dense forests that Patriofelis inhabited.

In fact, large oxyaenines had humeri that were more robust than any felid's, including that of Smilodon populator (Sorkin, 2008).

Data points for the Oxyaeninae (Creodonta, Oxyaenidae, genera Oxyaena and Patriofelis) and the Borhyaenoidea (Marsupialia, genera Prothylacynus and Thylacosmilus) with estimated body masses above 25 kg fall farther below the 95% prediction intervals for the linear regression line fitted to the data points for the ‘Felinae’ than do the data points for Smilodon and Panthera spelaea/atrox. This indicates that large oxyaenines and borhyaenoids possessed more robust humeri than any felid.

It is true that Oxyaena had wrists more adapted for weight bearing than Dipsalidictis, but that could simply be because the latter was a partially arboreal animal, while the former was terrestrial, as Gunnel & Gingerich (1991) themselves note. It's true that Patriofelis lacked raptorial claws on its hands, but it could have just been a predator that grappled with prey without claws to use as hooks or weapons (it wouldn't be the only predator that grapples/grappled prey without specialized raptorial claws; bears, amphicyonids, thylacosmilids).


Just so we're clear, I'm not making a statement on the matchup; I'm not much into them anymore and I try to avoid them nowadays. I am simply replying to this particular comment and want to inform readers with the information I presented here.