Editing Smilodon (section)

=== Paleopathology ===

[[File:Smilodon subchondral defects.PNG|thumb|left|Large [[subchondral defects]] in ''S. fatalis'' limb-joints (arrows)]]
Several ''Smilodon'' fossils show signs of [[ankylosing spondylitis]], [[hyperostosis]] and trauma.<ref name="Bjorkengren">{{cite journal |last1=Bjorkengren |first1=A. G. |last2=Sartoris |first2=D. J. |last3=Shermis |first3=S. |last4=Resnick |first4=D. |year=1987 |title=Patterns of paravertebral ossification in the prehistoric saber-toothed cat |journal=American Journal of Roentgenology |pmid=3103404 |doi=10.2214/ajr.148.4.779 |volume=148 |issue=4 |pages=779–782|doi-access= }}</ref> One study of 1,000 ''Smilodon'' skulls found that 36% of them had eroded [[parietal bone]]s, which is where the largest jaw muscles attach. They also showed signs of microfractures, and the weakening and thinning of bones possibly caused by mechanical stress from the constant need to make stabbing motions with the canines.<ref>{{cite journal |last=Duckler |first=G. L. |year=1997 |title=Parietal depressions in skulls of the extinct saber-toothed felid ''Smilodon fatalis'': evidence of mechanical strain |journal=Journal of Vertebrate Paleontology |doi=10.1080/02724634.1997.10011006 |volume=17 |issue=3 |pages=600–609|bibcode=1997JVPal..17..600D }}</ref> Bony growths where the [[deltoid muscle]] inserted in the humerus is a common pathology for a La Brea specimen, which was probably due to repeated strain when ''Smilodon'' attempted to pull down prey with its forelimbs. Sternum injuries are also common, probably due to collision with prey.{{Sfn|Antón|2013|p=199}}

The frequency of trauma in ''S. fatalis'' specimens was 4.3%, compared to 2.8% in the dire wolf, which implies the ambush predatory behavior of the former led to greater risk of injury than the pursuit predatory behavior of the latter. ''Smilodon'' remains exhibit relatively more shoulder and [[lumbar vertebrae]] injuries.<ref>{{cite journal|last1=Brown|first1=C.|last2=Balisi|first2=M.|last3=Shaw|first3=C. A.|last4=Van Valkenburgh|first4=B.|title=Skeletal trauma reflects hunting behaviour in extinct sabre-tooth cats and dire wolves|journal=Nature Ecology & Evolution|date=2017|volume=1|issue=5|pages=0131|doi=10.1038/s41559-017-0131|pmid=28812696|bibcode=2017NatEE...1..131B |s2cid=8008808}}</ref> A 2023 study documented a high degree of [[subchondral defects]] in limb-joint surfaces of ''S. fatalis'' and dire wolf specimens from the La Brea Tar pits that resembled [[osteochondrosis dissecans]]. As modern dogs with this disease are [[inbred]], the researchers suggested this would have been the case for the prehistoric species as well as they approached extinction, but cautioned that more research was needed to determine if this was also the case in specimens from other parts of the Americas.<ref name="Subchondral defects">{{cite journal |last1=Schmökel |first1=Hugo |last2=Farrell |first2=Aisling |last3=Balisi |first3=Mairin F. |title=Subchondral defects resembling osteochondrosis dissecans in joint surfaces of the extinct saber-toothed cat ''Smilodon fatalis'' and dire wolf ''Aenocyon dirus'' |journal=PLOS ONE |date=2023 |volume=18 |issue=7 |pages=e0287656 |doi=10.1371/journal.pone.0287656|pmid=37436967 |pmc=10337945 |bibcode=2023PLoSO..1887656S |doi-access=free }}</ref>

[[Osteomyelitis]] in the left [[fourth metacarpal bone]] has been reported in a ''S. populator'' specimen dating back to [[Marine Isotope Stage 5]]. This pathology resulted in the machairodont individual becoming incapable of flexing its toe and would have severely diminished its ability to hunt prey.<ref>{{Cite journal |last1=Luna |first1=Carlos A. |last2=Pool |first2=Roy R. |last3=Ercoli |first3=Marcos D. |last4=Chimento |first4=Nicolás R. |last5=Barbosa |first5=Fernando H. de S. |last6=Zurita |first6=Alfredo E. |last7=Cuaranta |first7=Pedro |date=22 May 2023 |title=Osteomyelitis in the manus of Smilodon populator (Felidae, Machairodontinae) from the Late Pleistocene of South America |url=https://www.sciencedirect.com/science/article/pii/S1871174X23000471 |journal=[[Palaeoworld]] |volume=33 |issue=2 |pages=517–525 |doi=10.1016/j.palwor.2023.05.001 |issn=1871-174X |access-date=5 February 2024 |via=Elsevier Science Direct}}</ref>