Taowu liui Temporal range: Early Pleistocene (Gelasian) | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Carnivora |
Suborder: | Feliformia |
Family: | Felidae |
Subfamily: | † Machairodontinae |
Genus: | † Taowu Jiangzuo, Werdelin, and Sun et al., 2022 |
Species: | †T. liui |
Binomial name | |
†Taowu liui Jiangzuo, Werdelin, and Sun et al., 2022 | |
Taowu is an extinct genus of machairodonts, a type of saber-toothed cat. It lived during the Early Pleistocene about 2.5 million years ago in East Asia. So far, only one skull is known, found in northern China. Based on this, a relatively small representative of the saber-toothed cats can be reconstructed, which only reached the size of a present-day leopard. In its dentition characteristics, it mediates between phylogenetic older forms such as Amphimachairodus and younger members such as Homotherium . The genus was scientifically described in 2022, but the find material was recovered as early as the 1930s.
Taowu was a rather small representative of the saber-toothed cats. It reached about the size of a present-day leopards. Found so far is a nearly complete skull of 23.5 cm length and 13.4 cm width, measured across the zygomatic arches. Only the articular surface on the occipital bone is missing from this one. In top view, the skull was relatively slender, comparatively narrower than in Homotherium or Xenosmilus , and possessed a rounded snout region. The snout did not taper behind the canine, but continuously increased in width posteriorly. Likewise, a cranial narrowing behind the orbits was only rather weakly pronounced. In lateral view, the frontal line showed a gentle uparching, and the nasal opening was recessed and concavely indented relative to the premaxilla. The incisor row thus appeared much more prominent than in, for example, Amphimachairodus . In plan view, the frontal area was broad. The nasal bones widened posteriorly. The infraorbital foramen was at the level of the fourth premolar, as was the anterior edge of the orbit. Bony ridges attached to the frontal bone, which united to form a parietal crest. The zygomatic arch bulged strongly dorsally. On the underside of the skull, the tympanic bulla was markedly distended. As a diagnostic feature, the glenoid fossa was on a raised platform, more prominent than in Amphimachairodus, and was very wide. The anterior palatal window was at the level of the canine, and the largest posterior one was at the level of the third premolar. [1] The upper dentition consisted of three incisors, one canine, two premolars, and two molars per half of the jaw. The incisors formed a closed arch and increased in size from the inside to the outside. An additional cusp existed on the third incisor. The canine tooth protruded up to 7.4 cm from the jaw and was flat blade-shaped in cross-section. Both the anterior and posterior edges showed fine serration. Adjacent to the canine, a diastema separated the anterior from posterior dentition. Unlike some other saber-toothed cats such as Lokotunjailurus , the second premolar was absent. The third and thus most anterior premolar was not reduced in size, which differs from Homotherium , Lokotunjailurus , or Xenosmilus . Overall, the tooth appeared elongated at a length of just under 2 cm, as did the much larger posterior premolar, which grew to a good 3.4 cm in length. The typical pointed cusps, the para-, meta-, and protoconus, existed on this, the latter only being small in formation. The anterior shear edge, the parastyle, had an elongate shape, from which the anteriormost section, the preparastyle, stood out only imperceptibly. [1]
The only fossil find of Taowu to date comes from Fancun, a locality about 36 km east of the township of Taigu, which in turn is part of the city of Jinzhong in the Chinese Shanxi province. The site and other areas in the region were excavated as early as the 1930s by American paleontologist Childs Frick. The various localities yielded numerous fossil materials, including several carnivores such as Homotherium as another representative of the saber-toothed cats, an extinct form of the lynx as well as the badger, Xenocyon as a member of the dogs, and the hyena Pachycrocuta . In addition, early relatives of modern horses also appeared. Especially the latter mentioned imply a predominant position in the Pleistocene, with the lower section being more likely. [2] [3] [1]
Taowu is a genus from the extinct subfamily of saber-toothed cats (Machairodontinae) within the family of cats (Felidae). The saber-toothed cats represent an ancient branch of cats, which according to molecular genetics studies, forms the sister group of today's big cats and small cats. Their separation from the common branch occurred about 20 million years ago in the Lower Miocene. [4] [5] [6] The feature that gave saber-toothed cats their name is their significantly enlarged canine teeth. However, this shows certain variations within the kinship community, which led to the establishment of different subgroups. Here, the Machairodontini have saber-like canines, the Smilodontini have dagger-like canines, and the Metailurini have less conspicuously large canines. With its leopard-like body size, Taowu represents one of the smallest representatives of the saber-toothed cats of the Pliocene and Pleistocene. In overall dentition, the form can be assumed to be somewhat intermediate between the more primitive Amphimachairodus and the terminal form Homotherium within the Machairodontini. This is recognizable, for example, from the third premolars, which are only slightly reduced in size. On the other hand, the anteriorly shifted incisors also suggest certain more modern characteristics. [7]
The skull underlying the genus Taowu was found as early as the 1930s in Fancun, part of the city of Jinzhong, in the Chinese Shanxi province. It was mentioned in individual publications in which various researchers classified it as belonging to Machairodus , but a precise characteristic description was not developed. [8] [9] Studies in 2022 necessitated a reevaluation. Jiangzuo Qigao and colleagues then established Taowu as a distinct form of saber-toothed cat in their scientific first description and presented the skull in detail. The generic name Taowu refers to the creature of the same name in Chinese mythology. Its striking characteristics include powerful tusks reminiscent of saber teeth. The species T. liui, introduced together with the genus, uses its epithet to honor the Chinese scientist Liu Jinyi, who had made significant contributions to the study of Pleistocene East Asian predators. [1]
Below is a phylogenetic tree of the Machairodontinae, based on the work of Jiangzuo and colleagues (2022). [1]
Machairodontinae |
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Machairodus is a genus of large machairodont or ''saber-toothed cat'' that lived in Africa, Eurasia and North America during the late Miocene. It is the animal from which the subfamily Machairodontinae gets its name and has since become a wastebasket taxon over the years as many genera of sabertooth cat have been and are still occasionally lumped into it.
Dinofelis is an extinct genus of sabre-toothed cats, possibly a member of the tribes Metailurini. They were widespread in Europe, Asia, Africa and North America from 5 million to about 1.2 million years ago. Fossils very similar to Dinofelis from Lothagam range back to around 8 million years ago, in the Late Miocene.
Smilodon is a genus of felid belonging to the extinct subfamily Machairodontinae. It is one of the best known saber-toothed predators and prehistoric mammals. Although commonly known as the saber-toothed tiger, it was not closely related to the tiger or other modern cats. Smilodon lived in the Americas during the Pleistocene epoch. The genus was named in 1842 based on fossils from Brazil; the generic name means "scalpel" or "two-edged knife" combined with "tooth". Three species are recognized today: S. gracilis, S. fatalis, and S. populator. The two latter species were probably descended from S. gracilis, which itself probably evolved from Megantereon. The hundreds of specimens obtained from the La Brea Tar Pits in Los Angeles constitute the largest collection of Smilodon fossils.
Homotherium is an extinct genus of machairodontine scimitar-toothed cat that inhabited North America, South America, Eurasia, and Africa during the Pliocene and Pleistocene epochs from around 4 million to 12,000 years ago. In comparison to Smilodon, the canines of Homotherium were shorter, and it was probably adapted to running down rather than ambushing prey.
A saber-tooth is any member of various extinct groups of predatory therapsids, predominantly carnivoran mammals, that are characterized by long, curved saber-shaped canine teeth which protruded from the mouth when closed. Saber-toothed mammals have been found almost worldwide from the Eocene epoch to the end of the Pleistocene epoch.
Nimravidae is an extinct family of carnivorans, sometimes known as false saber-toothed cats, whose fossils are found in North America and Eurasia. Not considered to belong to the true cats, the nimravids are generally considered closely related and classified as a distinct family in the suborder Feliformia. Fossils have been dated from the Middle Eocene through the Late Miocene epochs, spanning about 33.2 million years.
Machairodontinae is an extinct subfamily of carnivoran mammals of the family Felidae. 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.
Smilodontini is an extinct tribe within the Machairodontinae or "saber-toothed cat" subfamily of the Felidae. The tribe is also known as the "dirk-toothed cats". They were endemic to South America, North America, Europe, Asia, and Africa during the Miocene to Pleistocene, from 10.3 mya—11,000 years ago, existing for approximately 10.3 million years.
Paramachaerodus is an extinct genus of saber-tooth cat of the subfamily Machairodontinae, which was endemic to Europe and Asia during the late Miocene from 15 to 9 Ma.
Xenosmilus hodsonae is an extinct species of the Machairodontinae, or saber-toothed cats.
Thylacosmilus is an extinct genus of saber-toothed metatherian mammals that inhabited South America from the Late Miocene to Pliocene epochs. Though Thylacosmilus looks similar to the "saber-toothed cats", it was not a felid, like the well-known North American Smilodon, but a sparassodont, a group closely related to marsupials, and only superficially resembled other saber-toothed mammals due to convergent evolution. A 2005 study found that the bite forces of Thylacosmilus and Smilodon were low, which indicates the killing-techniques of saber-toothed animals differed from those of extant species. Remains of Thylacosmilus have been found primarily in Catamarca, Entre Ríos, and La Pampa Provinces in northern Argentina.
Megantereon was a genus of prehistoric machairodontine saber-toothed cat that lived in North America, Eurasia, and Africa. It is closely related to and possibly the ancestor of Smilodon.
Adelphailurus is an extinct genus of machairodontine (saber-toothed) cat inhabited western North America during the middle Pliocene.
Barbourofelidae is an extinct family of carnivorans of the suborder Feliformia, sometimes known as false saber-toothed cats, that lived in North America, Eurasia and Africa during the Miocene epoch and existed for about 7.9 million years. Thought to be an independent lineage from the Nimravidae and Machairodontinae, which had all attained elongated canines, recent research argues that it may be a subfamily of the Nimravidae, extending its biochronological range into the Miocene, although this issue is not yet fully resolved.
Nimravides is a genus of extinct saber-toothed cats that lived in North America during the Late Miocene, between 10.3 and 5.332 Ma. Despite its scientific name, Nimravides does not belong to the Nimravidae, but is a true cat belonging to the family Felidae.
Machairodontini is an extinct tribe of large saber-toothed cats of the subfamily Machairodontinae, that lived in Europe, Asia, Africa, and North America, during the Middle and Late Miocene.
Lokotunjailurus is an extinct genus of saber-toothed cats (Machairodontinae) which existed in Kenya and Chad during the Miocene epoch.
Homotherini is an extinct tribe of carnivoran mammals of the family Felidae. The tribe is commonly known as scimitar-toothed cats. These saber-toothed cats were distributed en North America, Europe, Asia, Africa, and South America from the Miocene to Pleistocene living from c. 23 Ma until c. 12,000 years ago.
Amphimachairodus is an extinct genus of large machairodonts. It is also a member of the tribe Homotherini within Machairodontinae and is most closely related to such species as Xenosmilus, Homotherium itself, and Nimravides. It inhabited Eurasia, Northern Africa and North America during the late Miocene epoch.
Tchadailurus is a genus of machairodontine felid from the late Miocene of Chad, Africa.