aphanistus (living 15.0 Ma) roamed Eurasia, as did its most studied descendants, members of the lion-sized genus Homotherium (living 3.0–5.0 Ma). ogygia (living 9.0 Ma) inhabited Spain (and perhaps additional territory), and its most studied descendants, the members of the tiger-sized genus Smilodon, lived up to 10,000 years ago in the Americas. (Though the Smilodontini ancestor was originally assigned to the genus Paramachairodus, it was later revised to the genus Promegantereon). Batollnes-1 unearthed new specimens of Promegantereon ogygia, a Smilodontini ancestor, and Machairodus aphanistus, a Homotheriini ancestor, shedding light on evolutionary history. Prior to the excavation of Batallones-1, the predominating hypothesis was that the highly derived saber-toothed phenotype arose rapidly through pleiotropic evolution. Until the recent discovery of the Late Miocene fossil depository known as Batallones-1 in the 1990s, specimens of Smilodontini and Homotheriini ancestors were rare and fragmentary, so the evolutionary history of the saber-toothed phenotype, a phenotype affecting craniomandibular, cervical forelimb and forelimb anatomy, was largely unknown. The phylogenetic relationships of Machairodontinae are shown in the following cladogram: † MachairodontinaeĮvolutionary history and origin of phenotype All recent felids have more or less conical-shaped upper canines.Ĭlassification Subfamily †Machairodontinae Saber-toothed and conical-toothed cats competed with each other for food resources, until the last of the former became extinct. In the Americas, they coexisted with the cougar, American lion, American cheetah, and jaguar until the late Pleistocene. Homotherium survived in northern Europe even until the late Pleistocene. In Africa and Eurasia, sabertooth cats competed with several pantherines and cheetahs until the early or middle Pleistocene. Saber-tooths also coexisted in many places with conical-toothed cats. DNA analysis published in 2005 confirmed and clarified cladistic analysis in showing that the Machairodontinae diverged early from the ancestors of modern cats and are not closely related to any living feline species. Machairodonts were not in the same subfamily as tigers, there is no evidence that they had tiger-like coat patterns, and this broad group of animals did not all live or hunt in the same manner as the modern tiger. The name 'saber-toothed tigers' is misleading. The last machairodontine genera, Smilodon and Homotherium, did not disappear until late in the Pleistocene, roughly 10,000 years ago in the Americas.īased on mitochondrial DNA sequences extracted from fossils, the lineages of Homotherium and Smilodon are estimated to have diverged about 18 Ma ago. However, some have recently regrouped the Metailurini within the other felid subfamily, the Felinae, along with all modern cats. Traditionally, three different tribes of machairodontines were recognized, the Smilodontini with typical dirk-toothed forms, such as Megantereon and Smilodon, the Machairodontini or Homotherini with scimitar-toothed cats, such as Machairodus or Homotherium, and the Metailurini, containing genera such as Dinofelis and Metailurus. Until the late Miocene, machairodontines co-existed at several places together with barbourofelids, archaic large carnivores that also bore long sabre-teeth. The earliest known machairodont genus is the middle Miocene Miomachairodus from Africa and Turkey. The early felid Pseudaelurus quadridentatus showed a trend towards elongated upper canines, and is believed to be at the base of the machairodontine evolution. The Machairodontinae originated in the middle Miocene of Europe. It dwarfs its modern relative, the common house cat, Felis catus. Μαχαιροῦς, from Ancient Greek: μάχαιρα, lit. 'makhaira', means a sword.Įvolution Family Felidae A male Amphimachairodus giganteus was one of the largest machairodonts. Besides the machairodonts, other saber-toothed predators also arose in the nimravids, barbourofelids, machaeroidines, hyaenodonts and even in two groups of metatherians (the thylacosmilid sparassodonts and the deltatheroideans). Sometimes, other carnivorous mammals with elongated teeth are also called saber-toothed cats, although they do not belong to the felids. The name means "dagger-tooth", from Greek μάχαιρα ( machaira), sword. The Machairodontinae contain many of the extinct predators commonly known as " saber-toothed cats", including the famed genus Smilodon, as well as other cats with only minor increases in the size and length of their maxillary canines. They were found in Asia, Africa, North America, South America, and Europe from the Miocene to the Pleistocene, living from about 16 million until about 11,000 years ago. Machairodontinae is an extinct subfamily of carnivoran mammals of the family Felidae (true cats). Homotherium venezuelensis, Machairodus aphanistus, Metailurus sp.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |