Compared to the usually massively built
dirk-toothed phenotype, apparent in Smilodon, Megantereon and the feliform Barbourofelis (just to list a few), their upper canines were smaller than those of equally sized cats of that phenotype, but they had serrated edges.[4][5] The scimitar-toothed phenotype has also evolved independently in other mammal families.[6]
The scimitar tooth form was used to assist in the hunting of herbivorous megafauna. With its hyper sharp and serrated form it was perfect for ripping flesh off of downed prey. However, if this tooth would come into contact with bone it could get caught, serrations worn off, or even completely broken thus leaving the organism without a food source, leading to starvation and death.[8][9]
There is a debate about how both the scimitar-tooth and the dirk-tooth evolved in felines and other mammals. the two sides of the debate revolve around whether it was derived from a sexual dimorphic trait or if it was completely natural selection that drove the creation of these phenotypes. The argument for sexual dimorphic origins stems from the fact that in mammals sexual dimorphic traits manifest as tools for males to compete for females. It is believed that the scimitar-tooth and the dirk-tooth were originally only in males for use in competition but then with the rise of mega-herbivores it became favorable for females to take up the trait as well.[10] The natural selection side of the debate argues that the scimitar and dirk-tooth both evolved because of the unfilled niche of predation of megaherbivores so the trait evolved to take advantage of said niche.[11]
^Jiangzuo, Q.; Werdelin, L.; Sun, Y. (2022). "A dwarf sabertooth cat (Felidae: Machairodontinae) from Shanxi, China, and the phylogeny of the sabertooth tribe Machairodontini". Quaternary Science Reviews. 284: Article 107517.
Bibcode:
2022QSRv..28407517J.
doi:
10.1016/j.quascirev.2022.107517.
^Rincon, A.; Prevosti, F.; Parra, G. (2011). "New saber-toothed cat records (Felidae: Machairodontinae) for the Pleistocene of Venezuela, and the Great American Biotic Interchange". Journal of Vertebrate Paleontology. 31 (2): 468–478.
doi:
10.1080/02724634.2011.550366.
hdl:11336/69016.
S2CID129693331.
^Martin, L.D. (1989). "Fossil history of the terrestrial Carnivora". In Gittleman, J.L. (ed.). Carnivore behaviour, ecology, and evolution. Vol. 1. Ithaca, IL: Cornell University Press. pp. 536–568.
^Meloro, C.; Slater, G. J. (2012). "Covariation in the skull modules of cats: the challenge of growing saber-like canines". Journal of Vertebrate Paleontology. 32 (3): 677–685.
doi:
10.1080/02724634.2012.649328.
S2CID55862923.
^Slater, G. J.; Valkenburgh, B. Van (2008). "Long in the tooth: evolution of sabertooth cat cranial shape". Paleobiology. 34 (3): 403–419.
doi:
10.1666/07061.1.
S2CID85353590.
^Van Valkenburgh, B.; Sacco, T. (2002). "Sexual dimorphism, social behavior, and intrasexual competition in large Pleistocene carnivorans". Journal of Vertebrate Paleontology. 22: 164–169.
doi:
10.1671/0272-4634(2002)022[0164:sdsbai]2.0.co;2.
S2CID86156959.
^Turner, Alan (1990). "The evolution of the guild of larger terrestrial carnivores during the Plio-Pleistocene in Africa". Geobios. 23 (3): 349–368.
doi:
10.1016/0016-6995(90)80006-2.