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Xenosmilus articulated replica skeleton offered by Bone clones
It measures 163 cent long 107 cent height at the head not the shoulders
Credit to Bone clones
Name: Xenosmilus (Foreign knife). Phonetic: Zee-no-smi-lus. Named By: Martin, Babiarz, Naples & Hearst 2000. Classification: Chordata, Mammalia, Carnivora, Felidae, Machairodontinae, Machairodontini. Species: X. hodsonae (type). Diet: Carnivore. Size: 1.7 to 1.8 meters long. Known locations: USA, Florida, Alachua County. Time period: Calabrian of the Pleistocene. Fossil representation: Remains of two almost complete individuals.
Although not as famous as Smilodon, Xenosmilus was nonetheless an exceptionally powerful Pleistocene era big cat that is estimated to have weighed between 230-400 kg. This estimate puts Xenosmilus within the same weight class as the largest species of Smilodon, and even though it was smaller, Xenosmilus would have been proportionately stronger for its size. Xenosmilus had been placed within the Machairodontinae group of sabre-toothed cats, mainly because of the large forward canines. However the canines were not as long as they were in other species, although the teeth in general do seem to be more robust possibly indicating that prey was still alive and struggling when they were brought into use. However the immensely powerful build of Xenosmilus meant that it was capable of wrestling almost any prey to the ground with ease, suggesting that teeth breakage would not have to be risked.
Because Xenosmilus has a powerful short legged build associated with the dirk toothed cats combined with broad upper canines as seen in the scimitar tooth cats, its exact classification has been a subject of some confusion. It could be that Xenosmilus displays a link between the two cat groups, or alternatively the features of Xenosmilus are simply a freak case of convergent evolution. Xenosmilus is estimated to have lived one million years ago during the Calabrian phase of the Pleistocene. However because only the two specimens from the same locale are known, the full temporal range of Xenosmilus in the fossil record cannot be established. However this placement does reveal that potential competition for Xenosmilus could have come from the earlier species of Smilodon, Dire wolves, and possibly the Dire wolf ancestor, Armbruster's Wolf.
One of the prey animals chosen by Xenosmilus are peccaries, often referred to as New World Pigs. This is confirmed by the presence of numerous peccary bones found in association with the Xenosmilus remains, and during the Pleistocene peccaries would have provided an abundant food source.
Further reading
- Three ways to be a saber-toothed cat. - Naturwissenschaften 87:41-44 - L. D. Martin, J. P. Babiarz, V. L. Naples & J. Hearst - 2000.
No I do not agree. Although Xenosmilus Hodsonae has a humerus almost equal in robust to Smilodon fatalis, it is more fragile than Smilodon populator. And as far as I know, Smilodon's musculature is much denser. @tigerluver @GuateGojira What are you thinking ?
(02-08-2022, 08:41 PM)tostwear Wrote: No I do not agree. Although Xenosmilus Hodsonae has a humerus almost equal in robust to Smilodon fatalis, it is more fragile than Smilodon populator. And as far as I know, Smilodon's musculature is much denser. @tigerluver @GuateGojira What are you thinking ?
A far I remember, Xenosmilus was smaller than Smilodon populator and Smilodon fatalis, the few specimens are smaller in all measurements, the largest skull was as large as an average sized Smilodon fatalis. The last real estimation that I remember was up to 230 kg for this felid, 300 kg is out of question and 400 kg is certainly imposible for the specimens known.
(02-13-2017, 07:54 AM)tigerluver Wrote: Body mass of Xenosmilus hodsonae
With four long bones, we have many different estimators. As Xenosmilus is not a giant as in the likes of the more popular Pleistocene felids, equations can be used but are far from needed.
The humerus is tiger-lion sized in length, thus a mass of 200-240 kg can be applied for this measurement alone. The articular length falls in the same tiger-lion mass range. The midshaft diameter is greater proportionately than that of lion and tiger humeri if you consider the Christiansen and Harris (2005) diameters are from the midshaft as well. Based on Christansen's (1999) assertion that the least tranverse diameter of the humeral shaft is "usually located at midshaft in humerus and femur but often more proximally and distally situated in the radius and tibia, respectively," it is probably okay to. I personally feel the least traverse diameter falls a bit south the midshaft. Nonetheless, Christiansen's data is probably midshaft and thus the midshaft would provide a mass range of 240-290 kg. All in all, the humerus indicates a specimen with a mass of ~235 kg assuming built in between the lion and the tiger, and some thing closer to 270 kg assuming a more tiger-like built.
The femur is short. The length based mass would on its own be around 170 kg. However, referring to the figure above about forelimb and hindlimb ratios, we see X. hodsonae had a very posteriorly sloped body mapping, thus estimating mass via femur length of a cat would be inaccurate. The femoral distal width is large for both a tiger and lion, but not exceptional. Thus a mass of 200-290 kg (yes, that's a large range but the two largest cats of today are proportioned quite differently in this regard) could apply for this measurement. The femoral midshaft diameter produces a lesser mass of 200-240 kg. Overall, if we ignore the length measurement, a mass of ~230 kg assuming built in between the lion and the tiger, and some thing closer to 270 kg assuming a more tiger-like built.
This is what I remembered. So like I said, there is no way that Xenosmilus weighed more than Smilodon fatalis, at least not with the specimens that we have. I remember that the largest skull known (until now....) was less than than 350 mm in GL, from this image we can see that the CBL is less than 290 mm:
*This image is copyright of its original author
Here is a reconstruction of the skull:
*This image is copyright of its original author
However, take in count that proportionally speaking, the head was relative small in comparison to the body, according with L. D. Martin and his team.
Here are some reconstructions from the book about this animal, sadly I still don't have the full one.
*This image is copyright of its original author
*This image is copyright of its original author
So, it seems that this cat was about the same weight as modern tigers and lions, but surpassed by S. fatalis.
Name: Xenosmilus (Foreign knife). Phonetic: Zee-no-smi-lus. Named By: Martin, Babiarz, Naples & Hearst 2000. Classification: Chordata, Mammalia, Carnivora, Felidae, Machairodontinae, Machairodontini. Species: X. hodsonae (type). Diet: Carnivore. Size: 1.7 to 1.8 meters long. Known locations: USA, Florida, Alachua County. Time period: Calabrian of the Pleistocene. Fossil representation: Remains of two almost complete individuals.
Although not as famous as Smilodon, Xenosmilus was nonetheless an exceptionally powerful Pleistocene era big cat that is estimated to have weighed between 230-400 kg. This estimate puts Xenosmilus within the same weight class as the largest species of Smilodon, and even though it was smaller, Xenosmilus would have been proportionately stronger for its size. Xenosmilus had been placed within the Machairodontinae group of sabre-toothed cats, mainly because of the large forward canines. However the canines were not as long as they were in other species, although the teeth in general do seem to be more robust possibly indicating that prey was still alive and struggling when they were brought into use. However the immensely powerful build of Xenosmilus meant that it was capable of wrestling almost any prey to the ground with ease, suggesting that teeth breakage would not have to be risked.
Because Xenosmilus has a powerful short legged build associated with the dirk toothed cats combined with broad upper canines as seen in the scimitar tooth cats, its exact classification has been a subject of some confusion. It could be that Xenosmilus displays a link between the two cat groups, or alternatively the features of Xenosmilus are simply a freak case of convergent evolution. Xenosmilus is estimated to have lived one million years ago during the Calabrian phase of the Pleistocene. However because only the two specimens from the same locale are known, the full temporal range of Xenosmilus in the fossil record cannot be established. However this placement does reveal that potential competition for Xenosmilus could have come from the earlier species of Smilodon, Dire wolves, and possibly the Dire wolf ancestor, Armbruster's Wolf.
One of the prey animals chosen by Xenosmilus are peccaries, often referred to as New World Pigs. This is confirmed by the presence of numerous peccary bones found in association with the Xenosmilus remains, and during the Pleistocene peccaries would have provided an abundant food source.
Further reading
- Three ways to be a saber-toothed cat. - Naturwissenschaften 87:41-44 - L. D. Martin, J. P. Babiarz, V. L. Naples & J. Hearst - 2000.
No I do not agree. Although Xenosmilus Hodsonae has a humerus almost equal in robust to Smilodon fatalis, it is more fragile than Smilodon populator. And as far as I know, Smilodon's musculature is much denser. @tigerluver @GuateGojira What are you thinking ?
Smilodon has wider limb bone dimensions. However, Xenosmilus is more stocky as its legs proportionately shorter for its torso. The humerus/ulna ratio (measure of stockiness) is 1.13 in Xenosmilus but 1.08 in S. populator. S. populator was much larger in absolute terms however.
