Xenosmilus

Zee-no-smi-lus.
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Liam Carter

Paleoanthropologist

Liam Carter explores the roots of humanity by studying early human fossils and artifacts. His ground-breaking work has provided a deeper understanding of our ancestors' lifestyles and social structures.

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Name

Xenosmilus ‭(‬Foreign knife‭)‬.

Phonetic

Zee-no-smi-lus.

Named By

Martin,‭ ‬Babiarz,‭ ‬Naples‭ & ‬Hearst‭ ‬2000.

Classification

Chordata,‭ ‬Mammalia,‭ ‬Carnivora,‭ ‬Felidae,‭ ‬Machairodontinae,‭ ‬Machairodontini.

Diet

Carnivore.

Species

X.‭ ‬hodsonae‭ (‬type‭)‬

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.

In Depth

       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.

SPECIES SPOTLIGHT