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User:Jts1882/sandbox/test

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Current test pages edit

User:Jts1882/sandbox/test/Phylogeny

User:Jts1882/sandbox/test/Felidae

Inputbox test edit

Mosses edit

Testing use of Newick strings edit

Content moved, but section kept to provide redirects form Talk page discussions

Open Tree of Life Test edit

Cladogram using newick data from Open Tree of Life Felidae ("ott_id":563159)

Moved to User:Jts1882/test/Newick#Open Tree of Life Test

Cladogram using Newick tree from Fish Tree of Life edit

Elopomorpha cladogram based on FishTree data moved to User:Jts1882/test/Newick#Fish Tree of Life test.

Charts SVG demo edit

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Temporary test zone edit

A saber-toothed cat (alternatively spelled sabre-toothed cat)[1] is any member of various extinct groups of predatory mammals that were characterized by long, curved saber-shaped canine teeth. The large maxillary canine teeth extended from the mouth even when it was closed. The saber-toothed cats were found worldwide from the Eocene epoch to the end of the Pleistocene epoch (42 mya – 11,000 years ago), existing for about 42 million years.[2][3][4]

The true saber-toothed cats are members of the subfamily Machairodontinae, which belongs to the family Felidae in the order Carnivora and is a sister group to the extant cats of the subfamilies Felinae and Pantherinae. One of the best known genera is Smilodon, species of which, especially S. fatalis, are popularly referred as "saber-toothed tigers".

The term saber-toothed cat is also applied to two other groups of feliform carnivores, the families Nimravidae and Barbourofelidae[5], which are also known as false saber-toothed cats to reflect the fact they are not true cats of family Felidae. The Nimravidae appeared first, entering the landscape around 42 mya and becoming extinct by 7.2 mya. The Barbourofelidae appeared around 16.9 mya and were extinct by 9 mya. These two would have shared some habitats with each other and with the machairodonts, which first appeared in the Miocene around 23 million million years ago and survived into the late Pleistocene, about 11,000 years ago.

The saber-toothed morphology developed independently in these three carnivore groups, as example of convergent evolution.[6] This convergence is remarkable due not only to the development of elongated canines, but also a suite of other characteristics, such as a wide gape and bulky forelimbs, that is so consistent that it has been termed the “saber-tooth suite”.[7] The saber-toothed morphology also developed independently in several other non-feliform mammalian carnivores, including the oxyaenid "creodont" genera Machaeroides and Apataelurus; and two lineages of metatherian mammals, the thylacosmilids of Sparassodonta and deltatheroideans, which are more closely related to marsupials than to the placental mammals.

Morphology edit

The different groups of sabre-toothed cats evolved their saber-toothed characteristics entirely independently. They are most known for having maxillary canines which extended down from the mouth even when the mouth was closed. Saber-toothed cats were generally more robust than today's cats and were quite bear-like in build. They were believed to be excellent hunters and hunted animals such as sloths, mammoths, and other large prey. Evidence from the numbers found at La Brea Tar Pits suggests that Smilodon, like modern lions, was a social carnivore.[8]

The first saber-tooths appear among the synapsids, or mammal-like reptiles; they were one of the first groups of animals to experience specialization of teeth, and many had long canines. Some had two pairs of upper canines with two jutting down from each side, but most had one pair of upper extreme canines. Because of their primitiveness, they are extremely easy to tell from machairodonts. With no coronoid process, many sharp "premolars" more like pegs than scissors and a very long, lizard-like head are among several characteristics that mark them out.

The second appearance is in Deltatheroida, a lineage of Cretaceous metatherians. At least one genus, Lotheridium, possess long canines, and given both the predatory habits of the clade as well as the generally incomplete material this may have been a more widspread adaptation.[9]

The third appearance of long canines is Thylacosmilus, which is the most distinctive of the saber-tooth mammals and is also easy to tell apart. It differs from machairodonts in possessing a very prominent flange and a tooth that is triangular in cross section. The root of the canines is more prominent than in machairodonts and a true sagittal crest is absent.

The fourth instance of saber teeth is from clade Oxyaenidae. The small and slender Machaeroides bore canines that were thinner than in the average machairodont. Its muzzle was longer and narrower.

The fifth saber-tooth appearance is the ancient family of carnivores, the nimravids, and they are notoriously hard to tell apart from machairodonts. Both groups have short skulls, tall sagittal crests, and their general skull shape is very similar. Some have distinctive flanges, and some have none at all, so this confuses the matter further. Machairodonts were almost always bigger, though, and their canines were longer and more stout for the most part, but exceptions do appear.

The sixth appearance is the barbourofelids. These carnivores are very closely related to actual cats, and as such, they are hard to tell apart. The best known barbourofelid is Barbourofelis, which differs from most machairodonts by a much heavier and more stout mandible, smaller orbits, massive and almost knobby flanges, and canines that are farther back. The average machairodont had well-developed incisors, but barbourofelids were more extreme.

The seventh and last of the saber-tooth group to evolve were the machairodonts themselves.

  1. ^ See for example "sabre-toothed cat" Encyclopædia Britannica. 2009. Encyclopædia Britannica Online. 26 Oct. 2009.
  2. ^ "PaleoBiology Database: ''Smilodon'', basic info". Paleodb.org. Retrieved 2012-09-06.
  3. ^ "PaleoBiology Database: ''Nimravidae'', basic info". Paleodb.org. Retrieved 2012-09-06.
  4. ^ "PaleoBiology Database: ''Barbourofelidae'', basic info". Paleodb.org. Retrieved 2012-09-06.
  5. ^ Barrett, Paul Z. (2016-01-01). "Taxonomic and systematic revisions to the North American Nimravidae (Mammalia, Carnivora)". PeerJ. 4: e1658. doi:10.7717/peerj.1658. PMC 4756750. PMID 26893959.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  6. ^ Antón, Mauricio (2013). Sabertooth (Life of the Past). Indiana University Press.
  7. ^ Meachen-Samuels, Julie A. "Morphological convergence of the prey-killing arsenal of sabertooth predators". Paleobiology. 38 (1): 1–14. doi:10.1666/10036.1.
  8. ^ Carbone, C.; Maddox, T.; Funston, P. J.; Mills, M. G.; Grether, G. F.; Van Valkenburgh, B. (2009). "Parallels between playbacks and Pleistocene tar seeps suggest sociality in an extinct sabretooth cat, Smilodon". Biol Lett. 5 (1): 81–85. doi:10.1098/rsbl.2008.0526. PMC 2657756. PMID 18957359.
  9. ^ Bi, S.; Jin, X.; Li, S.; Du, T. (2015). "A new Cretaceous metatherian mammal from Henan, China". PeerJ. 3: e896. doi:10.7717/peerj.896.{{cite journal}}: CS1 maint: unflagged free DOI (link)
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