Sivasmilus

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Sivasmilus
Temporal range: Miocene
Sivasmilus holotype Pilgrim1915.png
The holotype of Sivasmilus copei as depicted by Pilgrim (1915).
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Suborder: Feliformia
Family: Barbourofelidae
Genus: Sivasmilus
Kretzoi, 1929
Type species
Sivasmilus copei
Kretzoi, 1929
Pakistan Punjab relief map.svg
Red pog.svg
Chinji locality
Pakistan relief location map.jpg
Red pog.svg
Chinji locality
Map showing the location of the Chinji locality in Punjab, Pakistan.

Sivasmilus is a fossil genus of barbourofelid (false saber-toothed cat) containing only a single species, Sivasmilus copei. It is known from only a single specimen, a partial mandible collected from the Chinji Formation in the Lower Siwaliks in Pakistan, estimated to be from the Miocene. The fossil was originally described in 1915 when it was assigned to the fossil feline Sivaelurus chinjiensis , but was used as the basis of a new genus and species in 1929 by Hungarian paleontologist Miklós Kretzoi. Sivasmilus copei was a relatively small, cat-like animal.

Contents

History and naming

The holotype and only specimen assigned to Sivasmilus, a partial left mandible labelled GSI-D 151, was collected from the Chinji locality in the Salt Range, same as the holotype specimen of Sivaelurus chinjiensis ; that fact along with their similar size led paleontologist Guy Ellcock Pilgrim to provisionally assign GSI-D 151 to S. chinjiensis when he described the fossil in 1915. [1]

In 1929, paleontologist W. D. Matthew considered the holotype of Sivaelurus to be distinctly feline, but the mandible fragment GSI-D 151 to be distinctly machaerodont (saber-toothed cat) based on features of the teeth; [2] in that same year, Hungarian paleontologist Miklós Kretzoi reached the same conclusion in a wholly separate paper and erected the new genus and species Sivasmilus copei for it. [3] In his 1932 paper on Siwalik carnivorans, Pilgrim acknowledged this reassignment and agreed with its machaerodont affinities, stating that he had sought to avoid establishing an ill-defined genus when he assigned it to Sivaelurus. [4]

In 2018 a study noted that the mandible fragment seemed to fit the holotype of Sivaelurus (a near-complete right maxilla, or upper jaw bone) quite well. [5]

Description

The holotype of Sivasmilus copei is a partial left mandibular ramus with the canine tooth and second, third, and fourth premolars. The mandible overall is small and relatively slender, with a moderately developed mental crest, and two mental foramina situated under the second and third premolars respectively. The ramus is broken off after the fourth premolar and any further teeth are unknown; additionally, the front part of the fourth premolar is broken off just above the root. [1] [4] It was noted by several authors that the chin formed a more obtuse angle with the lower edge of the ramus than was usual in "machaerodonts" (which at the time included the nimravids and barbourofelids). [4] [6]

The canine tooth is relatively large and somewhat elongated, situated above the level of the premolars, with an oval cross-section and missing or vestigial keels. The diastema between the canine and the third premolar is relatively long, with a vestigial second premolar (a primitive trait) situated at about the halfway point. The third premolar itself was small, low-crowned, with only a weak posterior (rear) accessory cusp and encircling cingulum (a shelf at the base of the tooth), and no anterior (front) accessory cusp or parastyle at all. The front edge of the third premolar, however, had a distinct series of very fine serrations. The fourth premolar was a longer tooth, with a large posterior accessory cusp and a broader cingulum than in the third premolar, a strong metastyle behind the principal cusp and room for a parastyle in front of the principal cusp, though Pilgrim could not say if a parastyle was present or not. [1] [4]

Kretzoi thought that Sivasmilus lies evolutionary between Afrosmilus africanus and Propontosmilus sivalensis [= Paramachaerodus orientalis]. [3] Pilgrim, reviewing it in 1932, described it as a small and primitive species of machaerodont. [4]

Classification

The genus Sivasmilus was originally assigned to the subfamily Machairodontinae in the family Felidae, [4] though a 2021 study referred it without explanation to the Barbourofelinae. [7] This was followed by other papers, though a 2022 study mentioned in passing that it bore a greater resemblance to machairodontines but that an inspection of the known material was needed. [8] [9]

Related Research Articles

<i>Pseudaelurus</i> Extinct genus of carnivores

Pseudaelurus is a prehistoric cat that lived in Europe, Asia and North America in the Miocene between approximately twenty and eight million years ago. It is considered to be a paraphyletic grade ancestral to living felines and pantherines as well as the extinct machairodonts (saber-tooths), and is a successor to Proailurus. It originated from Eurasia and was the first cat to reach North America, when it entered the continent at about 18.5 Ma ending a 'cat-gap' of 7 million years. The slender proportions of the animal, together with its short, viverrid-like legs, suggest that it may have been an agile climber of trees.

Paramachaerodus is an extinct genus of saber-tooth cat of the subfamily Machairodontinae, which was endemic to Eurasia during the Middle and Late Miocene from 15 to 9 Ma. A 2022 phylogenetic analysis suggested that the genus may be polyphyletic.

<i>Amphicyon</i> Extinct genus of carnivores

Amphicyon is an extinct genus of large carnivorans belonging to the family Amphicyonidae, subfamily Amphicyoninae, from the Miocene epoch. Members of this family received their vernacular name for possessing bear-like and dog-like features. They ranged over North America, Europe, Asia, and Africa.

<span class="mw-page-title-main">Barbourofelidae</span> Extinct family of feliform carnivorans

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.

Miomachairodus is an extinct genus of large machairodontine containing only a single species, Miomachairodus pseudailuroides. It is known from Miocene-age fossils in China and Turkey and persisted until the Late Miocene. Fossils of this machairodont have been found in the Vallesian-age Bahe Formation in Shaanxi, China, and Yeni Eskihisar in Anatolia. This Turkish site is of Miocene age and is well known for its pollen studies.

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.

<i>Amphimachairodus</i> Extinct genus of carnivores

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.

<i>Hilarcotherium</i>

Hilarcotherium is an extinct genus of astrapotheriid mammals that lived in South America during the Middle Miocene (Laventan). The type species is H. castanedaii, found in sediments of the La Victoria Formation, part of the Honda Group in the department of Tolima in Colombia. In 2018, Carrillo et al. described a partial skull and mandible of a second species H. miyou from the Castilletes Formation in the Cocinetas Basin of northern Colombia, and estimated the body weight of the animal at 6,465 kilograms (14,253 lb).

Sivaladapis is a genus of adapiform primate that lived in Asia during the middle Miocene.

Sivapanthera is a prehistoric genus of felid described by Kretzoi in 1929. Species of Sivapanthera are closely related to the modern cheetah but differ from modern cheetahs by having relatively longer brain cases, flatter foreheads, narrower nostrils and larger teeth. In many ways, skulls of Sivapanthera show similarity to that of the puma, or even those of Panthera. Scholars differ on the validity of this genus, while some think that it should be treated as a distinct genus, others think that its members should be treated as members of the Acinonyx genus, or even as subspecies of Acinonyx pardinensis.

Hyperailurictis is an extinct genus of felid from Miocene North America. The Hyperailurictis species are Pseudaelurus-grade felids and thought to be the first felids in the Americas.

Miopanthera is an extinct genus of Pseudaelurus-grade felids.

<i>Sivaelurus</i> Extinct genus of carnivores

Sivaelurus is a fossil genus of felid containing only a single species, S. chinjiensis, which was described based on a partial right maxilla collected from the Chinji Formation in the Lower Siwaliks. The species was originally described by Guy Ellcock Pilgrim as Pseudaelurus chinjiensis in 1910, who later erected a new genus, Sivaelurus, for it in 1913.

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.

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.

Diamantofelis is an extinct genus of felids that lived in what is now Namibia during the Early Miocene. It contains a single species, Diamantofelis ferox.

Vishnufelis is a fossil genus of feline (cat) containing only a single species, Vishnufelis laticeps. It was described by Guy Ellcock Pilgrim in 1932, based on the first cranial material of a cat found in Asia: a fragmented skull found in the Chinji Formation, which dates back to the middle Miocene.

<i>Pachypanthera</i> Genus of prehistoric mammals

Pachypanthera is an extinct genus of pantherine felid that was recovered from the Late Miocene-aged Khorat sand pits in northeastern Thailand. It contains a single species, Pachypanthera piriyai, named and described in 2023.

Vinayakia is a fossil genus of proailurine felid with three species: Vinayakia nocturna, the type species, Vinayakia intermedia, and Vinayakia sarcophaga. All three species were based on fossils collected from the Miocene-aged Nagri and Chinji Formations of the Siwaliks in India and Pakistan.

Magerifelis is an extinct genus of feline with only one species assigned to it, Magerifelis peignei. It was described in 2024 based on seven fossils from the middle Miocene of Spain and France.

References

  1. 1 2 3 Pilgrim, G. (1915). "Note on the new feline genera Sivaelurus and Paramachaerodus and on the possible survival of the subphylum in modern times". Records of the Geological Survey of India. 45: 149.
  2. Matthew, W. D. (1929). "Critical Observations upon Siwalik Mammals". Bulletin of the American Museum of Natural History. LVI: 453, 498–499. hdl:2246/1325.
  3. 1 2 Kretzoi, M. (1929). "Materialen zur phylogenetischen Klassifikation der Aeluroideen". Cong. Int. Zool. Budapest. 10: 1297.
  4. 1 2 3 4 5 6 Pilgrim, G. (1932). "The fossil Carnivora of India". Palaeontologia Indica, Memoirs of the Geological Survey of India. 18: 206–209.
  5. Bonis, Louis de; Peigné, Stéphane; Mackaye, Hassane Taisso; Likius, Andossa; Vignaud, Patrick; Brunet, Michel (2018). "New sabre toothed Felidae (Carnivora, Mammalia) in the hominid-bearing sites of Toros Menalla (Late Miocene, Chad)". Geodiversitas. 40 (1): 81. doi: 10.5252/geodiversitas2018v40a3 . S2CID   134769588.
  6. Colbert, Edwin H. (1935). "Siwalik Mammals in the American Museum of Natural History". Transactions of the American Philosophical Society. 26: 122. doi:10.2307/1005467. JSTOR   1005467.
  7. Jiangzuo, Qigao; Sun, Danhui; Flynn, John J. (2021). "Paleobiogeographic implications of additional Felidae (Carnivora, Mammalia) specimens from the Siwaliks". Historical Biology. 33 (9): 1767–1780. Bibcode:2021HBio...33.1767J. doi:10.1080/08912963.2020.1737683. S2CID   216279658.
  8. Jasinski, Steven E.; Abbas, Sayyed Ghyour; Mahmood, Khalid; Babar, Muhammad Adeeb; Khan, Muhammad Akbar (2022). "New Carnivoran (Mammalia: Carnivora) specimens from the Siwaliks of Pakistan and India and their faunal and evolutionary implications". Historical Biology. 35 (11): 2217–2252. doi:10.1080/08912963.2022.2138376. S2CID   253346978.
  9. Mahmood, Khalid (2023). "Barbourofelines from the Middle-Late Miocene of the Siwaliks, Pakistan". Pakistan Journal of Zoology. 55 (6). doi: 10.17582/journal.pjz/20221013201049 . S2CID   257513528.