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Homotherium is an extinct genus of Homotherini belonging to the extinct subfamily Machairodontinae that inhabited North America, Eurasia, and Africa, as well as possibly South America during the Pliocene and Pleistocene epochs from around 4 million to 12,000 years ago. A probable descendant of Amphimachairodus, it was one of the last surviving members of Machairodontinae alongside the more famous sabertooth Smilodon, to which it was not particularly closely related. It was a large cat, comparable in size to a lion with a body mass of up to , functioning as an apex predator in the ecosystem it inhabited. It had an elongate neck and relatively elongate legs, a relatively short back and a very short tail, with the mummy of a H. latidens cub of Late Pleistocene age found in Siberia having a plain dark brown coat colour. In comparison to Smilodon, the canines of Homotherium were shorter, though still longer than those of living cats, and it is suggested to have had a different ecology from Smilodon as a moderate speed endurance pursuit predator adapted to running down large prey, such as antelope, Equinae, Bovini, and juvenile in open habitats, with Homotherium also proposed to have likely engaged in cooperative hunting.
Once widely distributed over most of the world's continents, the genus saw a protracted decline over the course of the Pleistocene, disappearing from Africa during the Early Pleistocene around 1.5 million years ago, and declining in abundance and distribution in Eurasia during the Middle Pleistocene, though with a handful of records in the Late Pleistocene. In North America, the genus survived until the end of the Late Pleistocene around 12,000 years ago, becoming extinct as part of the end-Pleistocene extinction event along with most other large animals native to the Americas. This followed the arrival of humans into the Americas, who may have caused a decline in populations of large prey on which Homotherium depended.
In 1918, the species Homotherium moravicum was described by Josef Woldřich based on remains found in what is now the Czech Republic. Homotherium davitashvili (also spelled davitasvilii) was described by Abesalom K. Vekua in 1972 based on fragmentary material found at the late Pliocene Kvabebi locality in Georgia in the southern Caucasus. Other material from Odessa in Ukraine was tentatively assigned to this species in 2004. In 1986, the species Homotherium darvasicum was described by Scharif Scharapov based on material from Kuruksay, Tajikistan in Central Asia. In 1989, another species Homotherium tielhardipiveteaui was named by Scharapov based on fossils also found in Tajikistan.
In 1936, Teilhard de Chardin described the new species Homotherium ultimus based on fossils from the Middle Pleistocene-aged Zhoukoudian cave complex near Beijing in northern China. Remains from the late Early Pleistocene-early Middle Pleistocene of Java in Indonesia have also been attributed to this species (as Homotherium ultimum), though others have attributed Javan remains of Homotherium to H. latidens. The also Javan Hemimachairodus zwierzyckii, originally named Epimachairodus zwierzyckii by Gustav Heinrich Ralph von Koenigswald in 1934 and placed in the new genus Hemimachairodus by the same author in 1974 (with indeterminate fossils attributed to Hemimachairodus also reported from Tajikistan (1988). 9785020033375 ISBN 9785020033375), is now also regarded as a synonym of Homotherium. In 1996, Homotherium hengduanshanense was described based on fossils of Late Pliocene-Early Pleistocene age from the Hengduan Mountains of Sichuan, southwestern China. (1996). 9787502741570, China Ocean Press. ISBN 9787502741570 Indeterminate remains of Homotherium have been reported from the Siwalik Hills of the northern Indian subcontinent, of Early - early Middle Pleistocene age.
In a 1954 publication, Jean Viret proposed that Homotherium crenatidens was the applicable species name for much of the Homotherium material in the Late Pliocene-Early Pleistocene of Europe. While Ficcarelli in 1979 regarded H. crenatidens and H. latidens as distinct species, this was disputed by Alan Turner in a 1999 publication, who considered that the proposed morphological differences separating the two species were invalid and the two species were not distinct.
A 2014 review recognised only one species of Homotherium in Eurasia during the Late Pliocene-Pleistocene, Homotherium latidens. Other named Homotherium species from this time period, including H. crenatidens, were found not to be distinct. Across time and space, the remains of H. latidens display considerable morphological variability, though there does not appear to be any clear pattern in this variation temporally or geographically (with the exception of the presence of "pocketing" of the margin of the masseteric fossa of the mandible appearing in Middle and Late Pleistocene H. latidens, but not earlier ones), with the morphological variation of the entire span of Homotherium in Eurasia from the Late Pliocene to the Late Pleistocene being similar to the variation found at the large sample for individuals from the Incarcal locality from the Early Pleistocene of Spain, supporting a single valid species. Some older material from the Pliocene of Eastern Europe (such as that from the Odesa catacombs in Ukraine) was tenatively considered to belong to a separate species. Some authors have continued to recognise Homotherium crenatidens as a valid, pan-Eurasian species chronologically earlier than H. latidens, with these authors suggesting that H. crenatidens spans the Late Pliocene-Early Pleistocene, while H. latidens spans the Middle-Late Pleistocene.
In 1972 the species Homotherium problematicum (originally Megantereon problematicus) was named by G. E. Collings, based on fragmentary material from the Makapansgat locality in northeast South Africa, of late Pliocene-Early Pleistocene age. Homotherium hadarensis was described by G. Petter and F.C. Howell in 1988, based on remains found in the Pliocene aged Hadar Formation of the Afar region of northern Ethiopia. In 2015, further material from the Hadar Formation was tentatively referred to H. hadarensis. A third species, Homotherium africanum (originally Machairodus africanus), was named by Arambourg in 1970 based on remains found in Aïn Brimba, in southern Tunisia, North Africa, dating to the early-middle Pliocene. In 1990, Alan Turner challenged the validity of H. problematicum and H. hadarensis, and later authors have generally refrained from referring African Homotherium fossils to any specific species due to their largely fragmentary nature. In 2021, indeterminate remains of Homotherium were reported from the Tobène locality of northwestern Senegal in West Africa, dating to the Early Pliocene. Indeterminate remains of Homotherium have also been reported from the Ahl al Oughlam locality in northern Morocco, dating to the Late Pliocene.
In 2011, a new species Homotherium venezuelensis was described by Ascanio Rincón et al. based on a partially crushed skull along with several partial lower jaws and teeth collected from tar seep deposits of Early to Middle Pleistocene age (around 1-0.5 million years ago) of Monagas in northeastern Venezuela. In 2022 and 2023, Jiangzuo et al. proposed that Homotherium venezuelensis be reassigned to the closely related homotheriin genus Xenosmilus (a genus originally described for Early Pleistocene aged fossils found in Florida) which was endorsed by Manzuetti et al. in 2024. Homotheriin remains had previously been reported from South America in the form of a lower jaw from southern Uruguay in 2004, dating to sometime between the Late Pliocene and the Middle Pleistocene, which the original 2004 study and Manzuetti et al. 2024 attributed to cf. Xenosmilus. The 2022 and 2023 studies found that Xenosmilus was nested within Homotherium as traditionally defined (with H. ischyrus more closely related to Xenosmilus than to other Homotherium species), making Homotherium without including the species in Xenosmilus paraphyletic.
In comparison to its likely ancestor Amphimachairodus, the upper display stronger serration, are larger and more arched, the upper second premolar (P2) is always absent, and the upper and lower third premolars (P3 and p3) are smaller, and the morphology of the upper fourth premolar (P4) displays differences. The Pliocene-Early Pleistocene North American H. ischyrus differs from the Eurasian H. latidens in having better developed upper and lower third premolars bearing three cuspids/cusps, with their mandibular ramus (the upper posterior part of the lower jaw that articlulates with the skull) being in comparison to H. latidens relatively low and elongate.
Compared to living Pantherinae big cats such as tigers and lions, Homotherium has a more elongate and narrower skull with a more elevated snout region, with the top of the skull (dorsal region) having a more straight outline with a high sagittal crest. Homotherium had shorter upper Canine tooth than members of the machairodont tribe Smilodontini such as Smilodon or Megantereon, but these were still longer than those of extant cats. (2025). 9783969291368, Propylaeum. ISBN 9783969291368 Its large upper canine saber teeth are broad, distinctly flattened and coarsely Serration. The large upper canines of Homotherium were likely hidden by the lips and gum tissues of the upper and lower jaws when the mouth was closed, similar to extant cats and unlike the larger upper canines of Smilodon. This hypothesis is further supported by comparable space between the canines and mandible at full closure of the jaws to modern cats; while Smilodon has significantly more space in this respect, likely for soft tissue to fit between the canine and mandible. The incisors are enlarged relative to those of modern big cats, and arranged in an arc at the front of the jaws, similar to hyenas and canines. The joining region between the two halves of the lower jaw (mandibular symphysis) is angular and high, with the coronoid process of the mandible being relatively short.
Preserved soft tissue of a three-week old cub of a H. latidens found in Siberia in 2020 and described in 2024 shows that the coat color for at least the juveniles of this species was a black or dark brown color with pale fur on the paws and chin. The fur on the corners of the mouth and back of the neck were longer than on the forelimbs of the mummy, and the pelage is generally dense all over the body. Additionally, the cub had wide rounded paws lacking a carpal pad. These are thought to be adaptations to living in snowy environments, and the fact that a three-week old had these features indicates that they developed them at a young age. A study on the microstructure of the cub's hair revealed that the medulla (the innermost part of the hair strand) made up only a relatively small part of the total diameter of the hair strands, suggesting that the heat-protective properties of the hair were poor and lacked specific adaptations to cold environments. It is likely that the cub was born in spring and died in summer.
It has been speculated based on its adaptation to open habitats and high levels of competition from other carnivores, that Homotherium probably relied on group hunting, which would make it easier to take down prey to compensate for their relatively weak forelimbs, increase the size of prey able to be taken, and enable distraction strategies to be employed during hunting, as well as to be better able to defend kills against kleptoparasitism (kill stealing) by other carnivores.
Analysis of the genome of a Homotherium specimen found in permafrost in Yukon in northern Canada, suggests that Homotherium experienced positive selection for genes related to respiration and the circulatory system, which may have been adaptations for endurance running. Positive selection for genes related to vision indicates that sight probably played an important role in hunting, suggesting that Homotherium was a Diurnality (daytime) hunter. Selection for genes related to cognition were tentatively suggested by researchers to possibly support the social hunting hypothesis. Isotope analysis of Homotherium and other animals from the Pliocene of Hadar, Ethiopia, dating to around 3.45–2.95 million years ago, suggests that its prey at this locality were large, on average around and primarily consumed plants. Prey animals primarily consisted of (in descending order of importance) antelopes belonging to the genus Tragelaphus, the swine Nyanzachoerus, the bovine Ugandax, the three-toed hipparionine equine Eurygnathohippus, and the antelope Damalborea. Homotherium was overlapping in diet though distinct in niche from that of the contemporary hyena Crocuta venustula.
Isotopic analysis of H. latidens from the Venta Micena locality in southeast Spain dating to the Early Pleistocene, around 1.6 million years ago, suggests that at this locality H. latidens was the apex predator and hunted large prey in open habitats, with the equine Equus altidens and bison likely forming a substantial portion of its diet. Juveniles of the mammoth Mammuthus meridionalis may also have formed a significant proportion (up to 10%) of their diet. It may have also occasionally taken other prey, such as juveniles of the large hippo Hippopotamus antiquus. At Venta Micena, Homotherium niche partitioned with the Smilodontini sabertooth Megantereon (a close relative of Smilodon) and the "European jaguar" Panthera gombaszoegensis, which hunted somewhat smaller prey in forested habitats. In Early Pleistocene Europe, the giant hyena Pachycrocuta brevirostris is likely to have presented a significant threat capable of stealing H. latidens kills.
Isotope analysis of specimens from Punta Lucero in northern Spain, dating to the early Middle Pleistocene (600-400,000 years ago), suggests that H. latidens at this locality exclusively consumed large (from to over ) prey, likely including aurochs, bison, red deer, and/or the giant deer Praemegaceros, and heavily overlapped in diet with the coexisting European jaguar Panthera gombaszoegensis.
In the late Early Pleistocene-early Pleistocene of Java and Early-Middle Pleistocene of China, Homotherium lived alongside the extant tiger, who may have competed with Homotherium.
At the Friesenhahn Cave site in Bexar County, south Texas, which dates to the Late Pleistocene (likely around 20-17,000 years ago, during the Last Glacial Maximum), the remains of almost 400 juvenile (on average around 2 years old) Columbian mammoths were discovered along with numerous Homotherium serum skeletons of all ages, from old adults to cubs. The sloped back and powerful lumbar section of Homotheriums vertebrae suggest that these animals could have been capable of pulling formidable loads; furthermore, broken upper canines - a common injury in fossils of other machairodonts such as Machairodus and Smilodon that would have resulted from struggling with their prey - is not seen in Homotherium, perhaps because their social groups would completely restrain prey items before any of the cats attempted to kill the target with their saber teeth, or because the canines were less frail due to being covered. Moreover, the bones of the young mammoths found in Friesenhahn Cave show distinctive marks matching the incisors of Homotherium, indicating that they could efficiently process most of the meat on a carcass and that the mammoths had been deposited in the caves by the cats themselves and not by scavengers. Examination of the bones also indicates that the carcasses of these juvenile mammoths were dismembered after being killed by the cats before being dragged away, suggesting that Homotherium would disarticulate their kill to transport it to a safe area such as a hidden lair or den and prevent competitors such as Dire wolf and from usurping the carcass, with the meatiest parts of the juvenile mammoths like limbs being preferentially transported to the cave. Isotopic analysis of H. serum dental remains at Friesenhahn Cave have confirmed that at this locality it predominantly fed on mammoths along with other C4 grazers, like bison and horses in open habitats, as well as possibly C4 browsers like the camel Camelops.
Isotopic analysis of H. serum specimens from Eastern Beringia (now Alaska and Yukon) suggests that in this region the species was not a specialised mammoth predator and consumed a variety of large prey, likely including bison, muskox, horse and reindeer, as well as probably .
Eurasian Homotherium began to decline in size during the latest part of the Early Pleistocene, and its body mass decline continued over the Middle Pleistocene, along with becoming increasingly rare in the Eurasian fossil record. This may be due to competition with other predators, such as the larger lion Panthera fossilis that arrived in Europe at the beginning of the Middle Pleistocene, and/or archaic humans. Across northern and southern China, Homotherium is thought to have gone extinct sometime during the Middle Pleistocene. The latest well-dated records of Homotherium in Europe date to the late Middle Pleistocene, around 300-200,000 years ago, with the exception of a single lower jaw bone from the North Sea which has been radiocarbon dated to around 28-30,000 years ago. It has been suggested that this may represent a Late Pleistocene dispersal from North America, rather than a continuous undocumented occupation of the region. In 2024, a mummy of a Homotherium latidens cub was reported from the Upper Pleistocene from the Badyarikha River, Yakutia in northeastern Siberia, dating to 35,471–37,019 years Before Present, marking the first recorded presence of the species in the Late Pleistocene of Asia. The youngest well dated remains of Homotherium serum date to around 12,715–12,655 years Before Present, found in southern Alberta, Canada, at the very end of the Late Pleistocene. Homotherium serum became extinct as part of the end-Pleistocene extinction event of most large mammals across the Americas. The extinction of Homotherium, along with fellow sabertooth Smilodon, at the end of the Late Pleistocene in North America has been suggested to be the result of the decline and extinction of the large prey species on which they depended.
A now-lost Upper Palaeolithic figurine found in Isturitz cave in southwest France has been suggested by some authors to represent Homotherium, but other authors have argued that it more likely represents a Panthera spelaea based on its anatomical proportions and the much greater abundance of cave lion remains compared to those of Homotherium in Late Pleistocene Europe.
At the end of the Late Pleistocene in North America, Homotherium serum co-existed with Paleo-Indians, the first humans to inhabit the Americas. The effect of human hunting of large herbivores which H. serum relied upon may have been a contributory factor in its extinction along with other large carnivores in North America.
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