Alagtsavbaatar Temporal range: | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Carnivora |
Suborder: | Feliformia |
Infraorder: | Aeluroidea |
Genus: | † Alagtsavbaatar Egi et al., 2016 |
Type species | |
† Stenoplesictis indigenus Dashzeveg, 1996 | |
Species | |
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Synonyms | |
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Alagtsavbaatar (meaning "Alag Tsav hero") is an extinct species of carnivorous cat-like carnivoran belonging to the infraorder Aeluroidea. It was endemic to Asia, with all known specimens being found in Mongolia, and lived during the late Eocene epoch. It is a monotypic genus, with the type and only known species being A. indigenus, and is named after the Alag Tsav locality where its remains were first discovered. [1]
The first remains of Alagtsavbaatar to be found were collected in September 1989 by a field party organized by the Geological Institute of the Mongolian Academy of Sciences. The holotype, a right mandibular fragment (PSS 40-15), was collected in the Alag Tsav locality in southeastern Mongolia. Dashzeveg (1996) described PSS 40-15 as the type specimen of a new species he named Stenoplesictis indigenus. The specific name is a Latin word meaning "local". [1]
Egi et al. (2016) found that PSS 40-15 showed dental features not matching Stenoplesictis, and concluded that this specimen represents a previously unknown genus. They erected the genus Alagtsavbaatar for the specimen, with A. indigenus being the type and only species. In addition, a partial left humerus (MPC-M30/80) and two fragments of right mandibles (MPC-M30/81 and MPC-M30/86) were referred to A. indigenus. These referred specimens all originate from Khoer Dzan locality of the Ergilin Dzo Formation, southeastern Mongolia. [2]
Using the carnivoran regression on the holotype specimen (PSS 40-15), Alagtsavbaatar has been estimated to have a body mass of 2.6 to 3.6 kg. This is smaller than Asiavorator , a feliform known to have been sympatric with Alagtsavbaatar, whose body mass has been estimated at 3.6 to 5.6 kg. [2]
The mandible has a slender and elongated form, with a depth of 9.4 to 9.5 mm. Mental foramina are present below the first and third premolars. [2]
All premolars of Alagtsavbaatar have two roots. Diastemata are present between the premolars, with the one between the second and third premolars being the longest. Based on the alveoli, the second premolar is longer and wider than the first. Buccal cingulids are found on the second, third and fourth premolars, being most strongly developed in the fourth premolar. The third premolar is as tall as the fourth, but its length is intermediate between those of the second and fourth premolars. [2]
The first molar has a buccolingually wide trigonid, high protoconid and lower paraconid. The metaconid is smaller than the paraconid, and is well expressed. The largest talonid cusp is the hypoconid. [1] Notches are observed between the protoconid and paraconid, as well as between the protoconid and metaconid. A cingulid surrounds the trigonid, while a hypoconid and entoconid border the talonid basin. The second molar has two roots, and its crown base is larger than the talonid of the first molar. In addition, the second molar has short talonid, weak buccal cingulid, well-developed paraconid and large protoconid base. [2]
The only known postcranial element of Alagtsavbaatar is a humeral fragment (MPC-M30/80) which appears broken near the distal end of the deltapectoral crest, with the remaining part measuring 41.2 mm in length. Distal to this crest, the narrow supinator crest ends. Proximal to the supinator crest, the anteroposterior and mediolateral diameters of the shaft are 6.5 and 5.3 mm respectively. A moderately developed medial epicondyle is present. Above the trochlear and capitular articular surfaces are the coronoid fossa and radial fossa respectively. A deep olecranon fossa with a thin wall is seen. The trochlea is narrow, with a wider medial rim than median end, forming a large angle against the mediolateral axis. The radial head had a developed capitular eminence, as evidenced by the capitular articular surface displaying a shallow groove on its lateral part. [2]
In the original description of the holotype, Dashzeveg (1996) assigned the species to the genus Stenoplesictis as S. indigenus, and placed it in the family Viverridae following Hunt (1989), which listed the Stenoplesictinae as a probable subfamily of viverrids. [1] [3] This subfamily would later be elevated to family level and renamed Stenoplesictidae. The placement of this species in Stenoplesictis was refuted by Peigné and de Bonis (1999) based on the dentition, though they did not assign the species to another genus. [4] Egi et al. (2016) did not assign Alagtsavbaatar to any family in their description of the genus, placing it as Feliformia incertae sedis , though they do state that the Mongolian small feliforms (Alagtsavbaatar, Asiavorator and Shandogolictis ) appear to form a monophyletic clade relative to the European genera Stenoplesictis , Palaeoprionodon and Haplogale , which independently evolved hypercarnivory. They state this clade is a sister taxon to the extant Feliformia excluding the Nandiniidae. [2]
The known fossils of Alagtsavbaatar originate from the late Eocene-aged Ergilin Dzo Formation of Mongolia. Sedimentary analyses suggest the formation was a floodplain environment with a braided stream network formed by fluvial systems. [5] In this environment, sympatric predators included the nimravids Nimravus and Eofelis , the entelodontid Entelodon , and the related stenoplesictid Asiavorator . [2] [6]
Catopsbaatar is a genus of multituberculate, an extinct order of rodent-like mammals. It lived in what is now Mongolia during the late Campanian age of the Late Cretaceous epoch, about 72 million years ago. The first fossils were collected in the early 1970s, and the animal was named as a new species of the genus Djadochtatherium in 1974, D. catopsaloides. The specific name refers to the animal's similarity to the genus Catopsalis. The species was moved to the genus Catopsalis in 1979, and received its own genus in 1994. Five skulls, one molar, and one skeleton with a skull are known; the last is the genus' most complete specimen. Catopsbaatar was a member of the family Djadochtatheriidae.
Andrewsarchus, meaning "Andrews' ruler", is an extinct genus of artiodactyl that lived during the Middle Eocene in what is now China. The genus was first described by Henry Fairfield Osborn in 1924 with the type species A. mongoliensis based on a largely complete cranium. A second species, A. crassum, was described in 1977 based on teeth. A mandible, formerly described as Paratriisodon, does probably belong to Andrewsarchus as well. The genus has been historically placed in the families Mesonychidae or Arctocyonidae, or was considered to be a close relative of whales. It is now regarded as the sole member of its own family, Andrewsarchidae, and may have been related to entelodonts. Fossils of Andrewsarchus have been recovered from the Middle Eocene Irdin Manha, Lushi, and Dongjun Formations of Inner Mongolia, each dated to the Irdinmanhan Asian land mammal age.
Cynodictis is an extinct amphicyonid carnivoran which inhabited Eurasia from the Late Eocene subepoch to the Early Oligocene subepoch living from 37.2 to 28.4 million years ago, existing for approximately 8.8 million years.
Protictitherium is an extinct genus of hyena that lived across Europe and Asia during the Middle and Late Miocene, it is often considered to be the first hyena since it contains some of the oldest fossils of the family. They were especially prolific in Turkey, where every species has been registered.
Feliformia is a suborder within the order Carnivora consisting of "cat-like" carnivorans, including cats, hyenas, mongooses, viverrids, and related taxa. Feliformia stands in contrast to the other suborder of Carnivora, Caniformia.
Altanius is a genus of extinct primates found in the early Eocene of Mongolia. Though its phylogenetic relationship is questionable, many have placed it as either a primitive omomyid or as a member of the sister group to both adapoids and omomyids. The genus is represented by one species, Altanius orlovi, estimated to weigh about 10–30 g (0.35–1.1 oz) from relatively well-known and complete dental and facial characteristics.
Brachyhyops is an extinct genus of entelodont artiodactyl mammal that lived during the Eocene Epoch of western North America and southeastern Asia. The first fossil remains of Brachyhyops are recorded from the late Eocene deposits of Beaver Divide in central Wyoming and discovered by paleontology crews from the Carnegie Museum of Natural History during the early 20th century. The type species, Brachyhyops wyomingensis, is based on a single skull and was named by E.H. Colbert in 1937, but was not officially described until 1938. During the latter half of the 20th century, additional specimens from North America have been recorded from Saskatchewan and as far south as Texas, indicating that Brachyhyops had a broad distribution and was well-dispersed throughout western North America.
Asiavorator is an extinct genus of civet-like carnivoran belonging in the family Stenoplesictidae. It was endemic to Asia and lived during the Eocene and Oligocene epochs.
Triaenops goodmani is an extinct bat from Madagascar in the genus Triaenops. It is known from three lower jaws collected in a cave at Anjohibe in 1996, and described as a new species in 2007. The material is at most 10,000 years old. A bat humerus from the same site could not be identified as either T. goodmani or the living T. menamena. T. goodmani is identifiable as a member of Triaenops or the related genus Paratriaenops by a number of features of the teeth, such as the single-cusped, canine-like fourth premolar and the presence of a gap between the entoconid and hypoconulid cusps on the first two molars. T. goodmani is larger than the living species of Triaenops and Paratriaenops on Madagascar, and on the first molar the protoconid cusp is only slightly higher than the hypoconid, not much higher as in the other species.
Dermotherium is a genus of fossil mammals closely related to the living colugos, a small group of gliding mammals from Southeast Asia. Two species are recognized: D. major from the Late Eocene of Thailand, based on a single fragment of the lower jaw, and D. chimaera from the Late Oligocene of Thailand, known from three fragments of the lower jaw and two isolated upper molars. In addition, a single isolated upper molar from the Early Oligocene of Pakistan has been tentatively assigned to D. chimaera. All sites where fossils of Dermotherium have been found were probably forested environments and the fossil species were probably forest dwellers like living colugos, but whether they had the gliding adaptations of the living species is unknown.
Afrasia djijidae is a fossil primate that lived in Myanmar approximately 37 million years ago, during the late middle Eocene. The only species in the genus Afrasia, it was a small primate, estimated to weigh around 100 grams (3.5 oz). Despite the significant geographic distance between them, Afrasia is thought to be closely related to Afrotarsius, an enigmatic fossil found in Libya and Egypt that dates to 38–39 million years ago. If this relationship is correct, it suggests that early simians dispersed from Asia to Africa during the middle Eocene and would add further support to the hypothesis that the first simians evolved in Asia, not Africa. Neither Afrasia nor Afrotarsius, which together form the family Afrotarsiidae, is considered ancestral to living simians, but they are part of a side branch or stem group known as eosimiiforms. Because they did not give rise to the stem simians that are known from the same deposits in Africa, early Asian simians are thought to have dispersed from Asia to Africa more than once prior to the late middle Eocene. Such dispersals from Asia to Africa also were seen around the same time in other mammalian groups, including hystricognathous rodents and anthracotheres.
Indraloris is a fossil primate from the Miocene of India and Pakistan in the family Sivaladapidae. Two species are now recognized: I. himalayensis from Haritalyangar, India and I. kamlialensis from the Pothohar Plateau, Pakistan. Other material from the Potwar Plateau may represent an additional, unnamed species. Body mass estimates range from about 2 kg (4.4 lb) for the smaller I. kamlialensis to over 4 kg (8.8 lb) for the larger I. himalayensis.
Sivaladapis is a genus of adapiform primate that lived in Asia during the middle Miocene.
Sivapardus is an extinct, little-known genus of feline with only one species assigned to it, Sivapardus punjabiensis. It was described in 1969 by the paleontologist Abu Bakr based on a partial mandible from the Upper Siwaliks in Pakistan; the locality it was found at is estimated to be from the Late Pliocene to Early Pleistocene. S. punjabiensis was a large cat with a short and broad snout that may have lived on open grasslands.
Gypsonictops is an extinct genus of leptictidan mammals of the family Gypsonictopidae, which was described in 1927 by George Gaylord Simpson. Species in this genus were small mammals and the first representatives of the order Leptictida, that appeared during the Upper Cretaceous.
Archaeogaia is an extinct genus of notoungulates that lived during the Early and Middle Paleocene of what is now Argentina. It is one of the oldest known unequivocal notoungulates.
Bonisicyon is an extinct genus of carnivoran mammals, belonging to the family Amphicyonidae. It is the last-surviving member of its family, living in East Africa during the end of the Miocene epoch. Known only from a damaged mandible and isolated teeth from the Nawata Formation, and possibly also the Lukeino Formation, its closer taxonomic affinities are unclear. It is notable for both its small size, and its unique dentition.
Lonchocyon is an extinct genus of arctoid carnivorans, with possible affinities to amphicyonids or hemicyonine bears. It contains a single species, Lonchocyon qiui, known from a single left mandible discovered at the fossil-bearing locality Haerhada at the base of the Baron Sog Formation, which is located in Inner Mongolia, China, and dates to the late Eocene. This taxon is notable for its large size in comparison to other arctoid carnivorans of the Eocene epoch, and for its hypercarnivorous adaptions, most notably its large canine and strongly reduced premolars. The genus name is a combination of Greek lonch, meaning spear and referencing the spear-like paraconid on its lower carnassial, and cyon, meaning dog. The specific name honours Professor Zhan-Xiang Qiu.
The Ergilin Dzo Formation, is a geologic formation in southeastern Mongolia. It preserves fossils of a wide variety of animals, which date back to the late Eocene epoch. The type fauna of the Ergilian Asian land mammal age is defined by the mammalian fossils of this formation.
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