Ysengrinia

Last updated

Ysengrinia
Temporal range: Late Oligocene to Early Miocene ~24–16  Ma
Ysengrinia Skull.jpg
Ysengrinia americana skull at Agate Fossil Beds National Monument
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family:† Amphicyonidae
Subfamily:† Thaumastocyoninae
Genus:† Ysengrinia
Ginsburg (1965)
Type species
Pseudocyon gerandianus
Viret, 1929
Other species
  • †Y. americana(Wortman, 1901)
  • †Y. depereti(Mayet, 1908)
  • †Y. tolosana(Noulet, 1876)
  • †Y. valentianaBelinchon & Morales, 1989

Ysengrinia is an extinct genus of carnivoran in the family Amphicyonidae, that lived during the Late Oligocene to Early Miocene. Fossil remains have been discovered in Western Europe, the United States and possibly China. The European species are among the earliest known members of the Thaumastocyoninae, a group of aberrant amphicyonids showcasing hypercarnivorous adations, but are only known from fragmentary remains. The American species is much better preserved and shows a robust, black-bear sized predator. These fossils play an important role in our understanding of the biotic interchange between Eurasia and North America during the earliest Miocene. However, more recent research suggests that the genus might be polyphyletic, and that several of its species should be excluded from Ysengrinia.

Contents

History

While fossils of belonging to this amphicyonid had been discovered since the late nineteenth century, their affinities were not recognized until a century later. Originally the remains were assigned to the genera Pseudocyon and Amphicyon. Kuss was the first to recognize the first to realize the similarities between the three European species in 1963, and two years later he assigned them all to Arctamphicyon. However, Ginsburg disagreed with this assignment, and erected Ysengrinia in 1965, with Y. gerandiana, previously referred to Pseudocyon, serving as its type species. The following year, he also moved the species Amphicyon tolosanus and Pseudocyon depereti to Ysengrinia, an arrangement generally followed by later authors, although Bonis (1973) suggested that Y. gerandiana might be synonymous with Y. tolosana. [1] [2]

In 1998, the species Ysengrinia ginsburgi was erected on the basis of fossils discovered at the locality Arrisdrift in Namibia, which would have made it the only species of the genus known from Africa. [3] However, newer studies have recognized the distinct anatomical differences between this taxon and the type species Y. gerandiana, resulting in the creation of the separate genus Namibiocyon for the amphicyonid from Arrisdrift. [4] Similarly, a tooth from the Askazansor Formation in Kazakhstan previously referred to Ysengrinia has since been moved to the genus Askazansoria . [5] [6]

Phylogeny

Heizmann and Kordikova erected the tribe Ysengrini in 2000, in which they included not only Ysengrinia, but also Crassidia and Amphiyconopsis, and which they considered to be in an intermediary position between the Amphicyoninae and Thaumastocyoninae. [7] More recent studies include the tribe within the latter subfamily, and furthermore suggest that Ysengrinia is polyphyletic. Cladistic analysis recovers Ysengrinia americana to be outside the group that includes the rest of the genus, while Ysengrinia valentiana is more closely related to Thaumastocyon than to the type species Ysengrinia gerandia. The authors also point out that Y. americana has notable differences in the upper dentition compared to the rest of the genus, [8] and displays a morphotype less adapted to hypercarnivory. Ysengrinia tolosana and Ysengrinia depereti, only known from their lower dentition, were not included in the analysis, and are in an uncertain systematic position. They suggest that Y. gerandia and Y. valentiana both belong to the Thaumastocyoninae, while Y. americana may either be the sister taxon of that subfamily, or be more closely related to Amphicyonines. [8] [9] It has been suggested that Peignecyon and an undescribed taxon from MN3/4 Baigneaux-en-Beauce descend from one of the numerous species of the genus. [10]

Below is the cladogram based on cranial, mandibular and dental characters, after Morales et al., 2021: [9]

Pseudocyonopsis landesquei

Daphoenodon superbus

Cynelos lemanensis

Ysengrinia americana

Thaumastocyoninae

Crassidia intermedia

Ysengrinia gerandia

Peignecyon felinoides

Tomocyon grivensis

Ysengrinia valentiana

Agnotherium antiquum

Ammitocyon kainos

Thaumastocyon bourgeoisi

Thaumastocyon dirus

Species

Ysengrinia americana

Illustration of the jaw of Ysengrinia americana Ysengrinia americana jaw.jpg
Illustration of the jaw of Ysengrinia americana

Y. americana is known from late Arikareean-aged rocks from Wyoming and Nebraska. The first fossils belonging to this species, a palate with nearly complete dentition, an upper canine and a calcaneum, were discovered by H.C. Clifford in 1875, and used as holotype for the description of "Amphicyon" americanus by Wortman in 1901. Some postcranial remains, several foot and limb bones, were discovered in the following years. It was not until 1972 that Hunt first proposed the presence of Ysengrinia in North America. Hunt then assigned "Amphicyon" americanus to the genus in 2002, resulting in the new combination Ysengrinia americana. He furthermore designated F:AM 54147, the only complete skull known of this genus, discovered in 1937 in the Anderson Ranch Formation, as its paratype. It is by far the most well-preserved member of the genus, and considerably larger than its European relatives. [1] However, more recent work has cast doubt on the inclusion of this species in the genus, partly since its dentition is less hypercarnivorous than that of European Ysengrinia. [9] The body mass of this species has been calculated at ~173 kg, but another estimation, derived from the diameter of the femur at the midshaft, results in a body mass of ~231 kg. [11]

Ysengrinia depereti

A poorly known species, originally described as "Pseudocyon" depereti on the basis of a fragmentary left mandibular ramus. It is known from the French site of Chilleurs-aux-Bois, which dates to the early Burdigalian (MN 3). [12] It had a broad m2 compared to Y. americana. [1]

Ysengrinia gerandiana

Originally described by Viret as Pseudocyon gerandius on the basis of a mandibular fragment, before Ginsburg created it the type species of Ysengrinia. It is known from the French site Saint-Gérand-le-Puy, as well as the German Ulm-Westtangente, both dating to MN 2. It shows reduced crushing molars in comparision with Y. americana, though its hypercarnivorous features are less pronounced than in Peignecyon. [1] [8] [12] Its body mass has been estimated at 89 kg. [13]

Ysengrinia tolosana

Originally described as "Amphicyon" tolosanus by Noulet in 1876, this is the oldest known species of Ysengrinia, known from the terminal Oligocene to early Miocene of France and Germany. A fossil discovered at Flörsheim described as Amphicyon robustum by Weitzel in 1930 was shown by Kuss to belong to the same species. [2] It is known by two mandibular fragments, one including p4-m2 from Le Cammas (probably dating to MP 30), and one from another with p3-m2 from Flörsheim (MP 30 or MN 2), as well as an isolated lower molar from Paulhiac (MN1), and the fragment of canine and a right humerus from Dieupentale (MP29-30). [14] Hunt notes that Y. tolosana shares more characteristics with Y. americana than the other European species do. [1] [12] [15] It is similar to Y. tolosana in size, but with a much wider second upper molar. [12]

Ysengrinia valentiana

This species is only known from two isolated molars discovered at the Orleanian locality of Buñol (MN 4), making it the only species known from Spain. Recent studies have indicated that its referral to Ysengrinia is questionable, and that it may be a more derived Thaumastocyonine. It shows transitional features between Peignecyon and Thaumastocyon., though the fragmentary nature of its remains makes concluding the closer relationship of this taxon impossible. [9] Its body mass has been estimated at 106kg. [16]

Description

Skull of Ysengrinia americana Ysengrinia americana.jpeg
Skull of Ysengrinia americana

Ysengrinia included medium to large-sized amphicyonids, with Hunt estimating the various species to have weighed between roughly 40 and 150 kg, though another study estimates that Y. americana could have grown even larger than that. [1] [11]

Its anterior premolars were reduced in size, as in Cynelos and Amphicyon , but its posterior molars were not enlarged, as in the latter genus. In Y. gerandia the reduction of the second molars, typical in thaumastocyonines, can be detected.[8] Y. tolosana shows wide diastemas between the premolars, and a characteristic second lower molar, with a wide trigonid and a high protoconid. [2] The skull of Y. americana, the only species of which a complete skull is known, was large, with a basilar length of 30 cm (for comparision, the skull length of Y. gerandia has been estimated at ~24-25 cm). [17] The snout was short and broadened at the level of the canines, which were remarkably large and robust, and are the reason for its deep and massive mandible. The braincase was remarkably small compared to the size of the skull, leading early authors to comment on its "primitive" characteristics. Its frontal region was only moderately inflated, with a flat, instead of domed, surface. Ysengrinia possessed a prominent sagittal crest, where massive temporal muscles could attach. The presence of a deep masseteric fossa bordered by thickened ventral and anterior margins indicates that a considerable force was developed during the occlusion of the carnassials and molars. The talonid of the first lower molar formed a crushing platform with the second and third molars. Like most other North American amphicyonids, it had a dental formula of 3-1-4-3. [1]

Restoration of Ysengrinia americana Ysengrinia americana1.jpg
Restoration of Ysengrinia americana

The postcranial remains of Ysengrinia show that it was a robust animal, with short, but powerful, limbs, with its forelimb being everted at the elbow. The morphology of its extremities is similar to that of ursids, though the relative length of the forelimb is longer than in either bears or tigers and comparable to that of a lion, whereas the relative length of the hindlimb is in between that of bears and big cats. Its shoulder is enormous and stabilized by the massive and thick muscles of the rotator cuff. The immense scapula includes a very broad scapular spine, and terminates in a well-developed acromion and a less-developed metacromion. Both this feature and the size of the glenoid fossa are more similar to polar bears than lions or tigers. The humerus is also similar to that of Ursus, as well as Amphicyon, but it lacked the deep olecranon fossa, and the associated secure locking of the ulna in the fossa, which prevents lateral bending of the elbow joint, making the condition seen in Ysengrinia more primitive in comparison. The iliopsoas muscle seems to have been huge, and the femur and tibia were similar to those of lions and tigers, although more robust in large males. The features of the astragalus are unlike those of plantigrade carnivorans such as ursids, and more similar to those of digitigrade felids, but it likely wasn't fully digitigrade like modern dogs and cats. It probably moved in a "subdigitigrade" stance, though while standing, the entire sole of the hindfoot likely touched the ground. Overall, these characteristics indicate that Ysengrinia lacked any cursorial adaptations and was an ambush hunter similar to big cats, relying on short bursts of speed to catch its prey, which was then disposed of with help of its powerful forelimbs and large canines. There is evidence of sexual dimorphism in Y. americana, as the females seem to have been smaller and more gracile than the males. [1]

Paleobiogeography and Paleoecology

The earliest amphicyonids were small-sized, but towards the end of the Chattian larger taxa, among them the comparatively enormous Ysengrinia, appeared for the first time. The geologically oldest fossils of the genus date to the late Oligocene, and are found at sites such as Dieupentale and Thézels, the former dating to MP 29, and the latter to MP 30, immediately prior to the Oligocene-Miocene transition, and it has been reported from the even earlier Pech Desse (MP 28, ~25 Ma). [18] [19] [20] Their emergence is linked to the turnover of Europe's carnivores around MP 26 (~26.5 Ma) which saw the diversification of amphicyonids, and the emergence of the first large members of the family; and the Microbunodon event, which took place during MP 28 (24.8-24 Ma), and saw a huge faunal turnover of 40% of the European ungulate fauna within 500k years, correlated with a major arrival of Asian immigrants. It is associated with the climate becoming more arid and seasonal, and the spread of wooded savannas. [21] The amphicyonids seem to have been strongly affected by these changes, and not only Ysengrinia, of likely European origin, but also Goupilictis , one of the smallest amphicyonids, and probably an Asian immigrant, are recorded for the first time during this time period. Ysengrinia coexisted with this smaller taxon, the medium-sized amphicyonids Cynelos and Brachycyon , as well as Hyaenodon , which seems to have been less affected by the environmental changes than the carnivorans. It is unclear if the amphicyonids, more adapted to wooded environments, were sympatric with the rather cursorial Hyaenodon, or if the two groups were environmentally separated. However, despite their apparent adaptations towards more open environments, the late Oligocene ultimately saw the local extinction of hyaenodonts, and the continuing diversification of amphicyonids, indicating that the latter benefitted from the environmental and faunal changes. [22]

In North America, the temnocyonine amphicyonids were the only large-sized carnivorans present during the Oligocene-Miocene boundary, after the local extinction of both nimravids and hyaenodonts. However, in the earliest Miocene, tectonic activities in Asia led to a dispersal event of Eurasian species into North America that lasted from circa 23 to 15.5 Ma, from the late Arikareean to the Hemingfordian. [23] Ysengrinia americana, which was considerably larger than even the largest temnocyonines, was among the earliest of these immigrants, first appearing around 23 Ma, alongside another amphicyonid, Cynelos, the chalicothere Moropus , the rhinoceros Menoceras and the ursid Cephalogale . [24] [25] [26] Another amphicyonid, Daphoenodon , first occurred at the same time, though this genus likely descended from earlier amphicyonids endemic to the New World, and is therefore not associated with the biotic interchange. [17] During this time period, the climate dried, and savannahs spread over the Great Plains, with trees mostly being restricted to riverbanks. Ephermal lakes were often the only source of water available, and mass deaths resulted when they dried out during the common droughts. [27] It is in these waterhole deposits that Ysengrinia was found. A notable locality is Beardog Hill, named for the unusually high number of amphicyonid fossils found here. Most of these belong either to Daphoenodon superbus, or the rarer Delotrochanter oryktes , a temnocyonine showcasing adaptions towards both durophagy and cursoriality, both of which were found in the remnants of their dens. Other carnivorans found here include two small canids ( Phlaocyon annectens and Cormocyon ), a small mustelid ( Promartes olcotti ) and the large, wolverine-like Megalictis simplicidens . Various prey animals dragged to the dens, including oreodont Merychyus and the camels Stenomylus and Oxydactylus , were also discovered. Ysengrinia, however, is absent from the dens, likely as a result of its large size, and only found at the waterhole, where Moropus, Menoceras and the huge, omnivorous Daeodon are the most commonly found taxons. [24] Y. americana was generally associated with waterholes and riparian habitats across its range. In the somewhat younger localities of the Anderson Ranch Formation (formerly known as Upper Harrison Formation), which date to the latest Arikareean, Ysengrinia occurs alongside the youngest known temnocyonines, Temnocyon macrogenys and Delotrochanter major, the Daphoenines Daphoenodon falkenbachi and Adilophontes brachykolos , as well as the immense Megalictis ferox. [28] [29] The following Arikareean-Hemingfordian boundary is characterized by a faunal turnover, which included the disappearance of all afromentioned carnivorans, including Y. americana and temnocyonines, as well as the appearance of several more Eurasian immigrants, among them the earliest North American members of the genus Amphicyon, which first occurred around 18.8 Ma. However, at least some of these sudden extinctions and appearances may be the result of the changing depositional environments, as the Anderson Ranch Formation was accumulated in a semi-arid grassland, whereas the Runningwater Formation was formed by fluvial environments. [29] While Ysengrinia has also been reported from New Mexico, Hunt's review of the American fossils of the genus does not include these fossils. [30] [1]

An upper molar discovered in the Japanese Orematsu Formation, which dates to 16.3-15.6 Ma, has also previously been referred to this genus. [31] Other authors have pointed out that this fossil is notably younger than the youngest known Ysengrinia fossils, and is morphologically similar to that of Cynelos idoneus, a taxon that is furthermore of similar age to the fossil from Japan. [1] [32] A partially preserved maxilla and isolated teeth of Ysengrinia, resembling Y. americana, have also been reported from the Xiejahe Fauna of China, which is part of the Shanwang Formation, and dates to circa 18 Ma. [9] [33]

Related Research Articles

<span class="mw-page-title-main">Amphicyonidae</span> Extinct family of carnivores

Amphicyonidae is an extinct family of terrestrial carnivorans belonging to the suborder Caniformia. They first appeared in North America in the middle Eocene, spread to Europe by the late Eocene, and further spread to Asia and Africa by the early Miocene. They had largely disappeared worldwide by the late Miocene, with the latest recorded species at the end of the Miocene in Africa. They were among the first carnivorans to evolve large body size. Amphicyonids are colloquially referred to as "bear-dogs".

<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">Ursoidea</span> Superfamily of mammals

Ursoidea is a superfamily of arctoid carnivoran mammals that includes the families Subparictidae, Amphicynodontidae, and Ursidae. The last family includes the extant lineages of bears, as well as the extinct Hemicyoninae and Ursavinae.

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

Agnotherium is a genus of large sized carnivoran mammals, belonging to the Amphicyonidae, which has been found in Western Europe, and possibly China and Northern Africa, and lived during the Late Miocene epoch. Despite only being known from fragmentary remains, the genus notable for hypercarnivorous adaptions, which have been said to represent the "apex" among its family.

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

Gobicyon is an extinct genus of large-sized carnivoran mammals, belonging to the Amphicyonidae, that was discovered in China, Mongolia, and Serbia, and lived during the Middle Miocene epoch. Despite only being known from rather fragmentary remains, recent discoveries showcase that it was an aberrant member of the subfamily Haplocyoninae, with adaptions towards bone-crushing similar to those of a hyaena.

<span class="mw-page-title-main">Amphicyoninae</span> Extinct subfamily of carnivores

Amphicyoninae is a subfamily of extinct amphicyonids, large terrestrial carnivores sometimes called "bear-dogs", belonging to the suborder Caniformia, which inhabited North America, Eurasia, and Africa from the middle Eocene to the late Miocene.

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

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.

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

Palaeogale is an extinct genus of carnivorous mammal known from the Late Eocene, Oligocene, and Early Miocene of North America, Europe, and Eastern Asia. A small carnivore often associated with the mustelids, Palaeogale might have been similar to living genets, civets, and linsangs.

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

Gustafsonia is an extinct genus of carnivoran belonging to the family Amphicyonidae. The type species, Gustafsonia cognita, was described in 1986 by Eric Paul Gustafson, who originally interpreted it as a miacid and named it Miacis cognitus. It was subsequently considered to be the only species of the diverse genus Miacis that belonged to the crown-group Carnivora, within the Caniformia, and it was ultimately assigned to the family Amphicyonidae. The type specimen or holotype was discovered in Reeve's bonebed, western Texas, in the Chambers Tuff Formation in 1986. The University of Texas holds this specimen. It is the only confirmed fossil of this species.

<span class="mw-page-title-main">Hyaenodonta</span> Extinct order of mammals

Hyaenodonta is an extinct order of hypercarnivorous placental mammals of clade Pan-Carnivora from mirorder Ferae. Hyaenodonts were important mammalian predators that arose during the early Paleocene in Europe and persisted well into the late Miocene.

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

Magericyon is an extinct genus of Amphicyonid ("bear-dog") that lived during the Miocene 10-9 Ma in what is now Spain.

Ammitocyon is a genus of large sized carnivoran mammals, belonging to the Amphicyonidae, that lived during the Late Miocene in what is now Spain. It is notable for its extreme adaptations towards hypercarnivory, its extremely robust skeleton, and was one of the last surviving members of its family.

<span class="mw-page-title-main">Thaumastocyoninae</span> Extinct subfamily of amphicyonids

Thaumastocyoninae is an extinct subfamily of amphicyonids, large terrestrial carnivores, which inhabited what is now Europe during the Miocene epoch. The subfamily was erected by Hürzeler (1940), and is defined by the complete suppression of m1 metaconid, reduction of the premolars, except the p4, which is reinforced, and the oblique abrasion of the teeth, and the possession of hypercarnivorous tendencies. Thaumastocyonines are poorly known, with only about 65 dental specimens, most of those isolated teeth, being known as of 2020, although more complete remains have recently been discovered.

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.

Namafelis is an extinct genus of felids that lived in what is now Namibia during the Early Miocene. It contains a single species, Namafelis minor. Closely related to Diamantofelis, it is of “Pseudaelurus-grade”, and therefore a rather basal member of the cat family.

Myacyon is an extinct genus of large sized carnivoran mammals, belonging to the family Amphicyonidae, that lived in Africa during the Miocene epoch. Due to the limited scope and fragmentary nature of the severely damaged holotype, as well as the illustrations in its descriptions, which have been called inadequate, usage of this genus poses serious issues. However, it is notable for being one of the last surviving members of its family and its adaptions to hypercarnivory. Its relationships to other amphicyonids are obscure, and it is not closely related to Bonisicyon, the other late surviving African genus, although it has been proposed that it descends from a species of Cynelos or Namibiocyon.

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.

Namibiocyon is an extinct genus of carnivoran mammals, belonging to the family Amphicyonidae, that lived in Namibia during the Early Miocene epoch. Before the erection of this taxon in 2022, the type and only species, N. ginsburgi, had been assigned to a variety of other genera. It is notable for its adaptions toward hypercarnivory.

Delotrochanter is an extinct genus of large-sized carnivoran mammals, belonging to the Amphicyonidae, that lived in the Great Plains of North America during the Oligocene to Early Miocene. This genus includes some of the largest and last surviving members of the subfamily Temnocyoninae. it furthermore possesses adaptions towards both bone-crushing and cursoriality.

Peignecyon is an extinct genus of large carnivorans belonging to the family Amphicyonidae. It belongs to the subfamily Thaumastocyoninae, which is characterized by their adaptions towards hypercarnivory. Whereas most other thaumastocyonines are often only known from fragmentary remains and isolated teeth, Peignecyon is known from a variety of well-preserved remains. It contains a single species, P. felinoides from the Early Miocene of the Czech Republic.

References

  1. 1 2 3 4 5 6 7 8 9 10 Hunt, R.M. (2002). "Intercontinental migration of Neogene Amphicyonids (Mammalia, Carnivora): Appearance of the Eurasian beardog Ysengrinia in North America". American Museum Novitates (3384): 1–53. doi:10.1206/0003-0082(2002)384<0001:imonam>2.0.co;2. hdl:2246/2873. S2CID   55870347.
  2. 1 2 3 "Contribution à l'étude des Mammifères de l'Aquitanien de l'Agenais: Rongeurs, Carnivores, Périssodactyles - Scientific Publications of the Muséum national d'Histoire naturelle, Paris". sciencepress.mnhn.fr. Retrieved 2024-09-16.
  3. ↑ Morales, J.; Pickford, M.; Soria, D.; Fraile, S. (1998). "New carnivores from the basal Middle Miocene of Arrisdrift, Namibia". Eclogae Geologicae Helvetiae. 91: 27–40.
  4. ↑ Morales, Jorge; Pickford, Martin (2022). "The taxonomic status of "Ysengrinia" ginsburgi Morales et al. 1998 (Amphicyonidae, Carnivora) from the basal middle Miocene of Arrisdrift, Namibia" (PDF). Communications of the Geological Survey of Namibia. 24: 1–16 – via Google Scholar.
  5. ↑ De Bonis, L.; Brunet, M.; Kordikova, E. G.; Mavrin, A. V. (1997). "Oligocene-Miocene sequence stratigraphy and vertebrate paleontology of western and southern Betpakdala Steppe, South Kazakhstan". Mémoires et travaux de l'Institut de Montpellier: 225–240 – via Researchgate.
  6. ↑ Peigné, Stéphane; Chaimanee, Yaowalak; Yamee, Chotima; Tian, Pannipa; Jaeger, Jean-Jacques (2006-04-01). "A new amphicyonid (Mammalia, Carnivora, Amphicyonidae) from the late middle Miocene of northern Thailand and a review of the amphicyonine record in Asia". Journal of Asian Earth Sciences. 26 (5): 519–532. Bibcode:2006JAESc..26..519P. doi:10.1016/j.jseaes.2004.11.003. ISSN   1367-9120.
  7. ↑ Heizmann, Elmar P.J.; Kordikova, Elena G. (2000). "Zur systematischen Stellung von "Amphicyon" intermedius H. v. MEYER, 1849 (Carnivora, Amphicyonidae)" (PDF). Carolinea. 58.
  8. 1 2 3 Morales, J., Fejfar, O., Heizmann, E., Wagner, J., Abella, J., Valenciano, A. (2019): A new Thaumastocyoninae (Amphicyonidae, Carnivora) from the early Miocene of Tuchořice Czech Republic. – Fossil Imprint 75: 397–411. https://doi.org/10.2478/if-2019-0025
  9. 1 2 3 4 5 Morales, Jorge; Abella, Juan; Sanisidro, Oscar; Valenciano, Alberto (2021). "Ammitocyon kainos gen. Et sp. Nov., a chimerical amphicyonid (Mammalia, Carnivora) from the late Miocene carnivore traps of Cerro de los Batallones (Madrid, Spain)". Journal of Systematic Palaeontology. 19 (5): 393–415. doi:10.1080/14772019.2021.1910868.
  10. ↑ Morlo M, Bastl K, Habersetzer J, Engel T, Lischewsky B, Lutz H, von Berg A, Rabenstein R, Nagel D. 2020. The apex of amphicyonid hypercarnivory: solving the riddle of Agnotherium antiquum Kaup, 1833 (Mammalia, Carnivora). Journal of Vertebrate Paleontology 39(5):e1705848 DOI 10.1080/02724634.2019.1705848.
  11. 1 2 Figueirido; Pérez-Claros; Hunt; Palmqvist (2011). "Body Mass Estimation in Amphicyonid Carnivoran Mammals: A Multiple Regression Approach from the Skull and Skeleton". Acta Palaeontologica Polonica. 56 (2): 225–246. doi: 10.4202/app.2010.0005 . S2CID   56051166.
  12. 1 2 3 4 Peigné, Stéphane (2003). The Amphicyonidae (Mammalia: Carnivora) from Ulm-Westtangente (MN 2, Early Miocene), Baden-Württemberg, Germany: systematics and ecomorphology; with 14 tables. Stuttgarter Beiträge zur Naturkunde / B, 343. Staatliches Museum für Naturkunde.
  13. ↑ Costeur, Loïc; Maridet, Olivier; Peigné, Stéphane; Heizmann, Elmar P. J. (2012-01-01). "Palaeoecology and palaeoenvironment of the Aquitanian locality Ulm-Westtangente (MN2, Lower Freshwater Molasse, Germany)". Swiss Journal of Palaeontology . 131 (1): 183–199. doi:10.1007/s13358-011-0034-3. ISSN   1664-2384.
  14. ↑ Baudelot, S.; Olivier, Ph. (1978-01-01). "Les Rongeurs (Mammalia, Rodentia)de l'Oligocène terminal de Dieupentale (Sud-Ouest de la France: Tarn et Garonne)". Geobios. 11 (1): 5–19. doi:10.1016/S0016-6995(78)80015-1. ISSN   0016-6995.
  15. ↑ Zhanxiang, Qiu (2003). "Chapter 2: Dispersals of Neogene Carnivorans between Asia and North America". Bulletin of the American Museum of Natural History. 279: 18–31. doi:10.1206/0003-0090(2003)279<0018:C>2.0.CO;2. ISSN   0003-0090.
  16. ↑ Solé, Floréal; Lesport, Jean-François; Heitz, Antoine; Mennecart, Bastien (2022-06-15). "A new gigantic carnivore (Carnivora, Amphicyonidae) from the late middle Miocene of France". PeerJ. 10: e13457. doi: 10.7717/peerj.13457 . ISSN   2167-8359. PMC   9206431 . PMID   35726261.
  17. 1 2 Hunt, Robert M. (1998). "Amphicyonidae". In Janis, C. M.; Scott, K.M.; Jacobs, L. L. (eds.). Evolution of tertiary mammals of North America, volume 1: Terrestrial carnivores, ungulates and ungulatelike mammals. Cambridge, UK: Cambridge University Press. pp. 196–227. ISBN   978-0521355193.
  18. ↑ Blanchon, Maxime; Antoine, Pierre-Olivier; Blondel, Cécile; de Bonis, Louis (2018-07-01). "Rhinocerotidae (Mammalia, Perissodactyla) from the latest Oligocene Thézels locality, SW France, with a special emphasis on Mesaceratherium gaimersheimense Heissig, 1969". Annales de Paléontologie. 104 (3): 217–229. doi:10.1016/j.annpal.2018.06.001. ISSN   0753-3969.
  19. ↑ Bonis, Louis de; Guinot, Y. (1987). "Le gisement de Vertébrés de Thézels (Lot) et la limite Oligo-Miocène dans les formations continentales du bassin d'Aquitaine". Münchner Geowissenschaftliche Abhandlungen.
  20. ↑ Remy; Crochet; Sigé; Sudre; de Bonis; Vianey-Liaud; Godinot; Hartenberger; Lange-Badré; Comte (1987). "Biochronologie des phosphorites du Quercy: Mise à jour des listes fauniques et nouveaux gisements de mammifères fossiles". Münchner Geowiss. Abh.
  21. ↑ Mennecart, Bastien (2015-02-18). "The European Ruminants during the "Microbunodon Event" (MP28, Latest Oligocene): Impact of Climate Changes and Faunal Event on the Ruminant Evolution". PLOS ONE. 10 (2): e0116830. doi: 10.1371/journal.pone.0116830 . ISSN   1932-6203. PMC   4334963 . PMID   25692298.
  22. ↑ Solé; Dubied; Le Verger; Mennecart (2018). "Niche partitioning of the European carnivorous mammals during the paleogene". PALAIOS. 33 (11): 514–523. doi:10.2110/palo.2018.022.
  23. ↑ Jiang, H.; Deng, T.; Li, Y.; Xu, H. (2015-08-27). Neogene tectonics and climate forcing of carnivora dispersals between Asia and North America (Report). Geodynamics. doi: 10.5194/sed-7-2445-2015 .
  24. 1 2 Jr, Robert M. Hunt; Skolnick, Robert; Kaufman, Joshua (2019). The Carnivores of Agate Fossil Beds National Monument. Lulu.com. ISBN   978-1-60962-143-8.
  25. ↑ Hunt, Robert M.; Stepleton, Ellen (2015-01-02). "A skull of the immigrant Eurasian beardog Cynelos (Carnivora, Amphicyonidae) from the early Miocene of southern California". Journal of Vertebrate Paleontology. 35 (1): e891229. doi:10.1080/02724634.2014.891229. ISSN   0272-4634.
  26. ↑ Coombs, Margery C.; Hunt, Robert M. (2015-11-02). "New material of Moropus (Perissodactyla, Chalicotheriidae, Schizotheriinae) from the early Hemingfordian Rose Creek Member of the John Day Formation, Oregon, U.S.A." Journal of Vertebrate Paleontology. 35 (6): e1009992. doi:10.1080/02724634.2015.1009992. ISSN   0272-4634.
  27. ↑ Graham, John (2009-01-01). "Agate Fossil Beds National Monument: Geologic Resources Inventory Report". U.S. National Park Service Publications and Papers.
  28. ↑ Hunt, Robert (2011-01-01). "Evolution of large carnivores during the mid-Cenozoic of North America: The Temnocyonine Radiation (Mammalia, Amphicyonidae)". Papers in the Earth and Atmospheric Sciences.
  29. 1 2 HUNT, ROBERT M. (2002). <0001:nacmdf>2.0.co;2 "New Amphicyonid Carnivorans (Mammalia, Daphoeninae) from the Early Miocene of Southeastern Wyoming". American Museum Novitates (3385): 1–41. doi:10.1206/0003-0082(2002)385<0001:nacmdf>2.0.co;2. ISSN   0003-0082.
  30. ↑ Lucas, Spencer G.; Sullivan, Robert M. Vertebrate Paleontology in New Mexico: Bulletin 68. New Mexico Museum of Natural History and Science.
  31. ↑ Kohno, Naoki (1997). "The first record of an amphicyonid (Mammalia : Carnivora) from Japan, and its implication for amphicyonid paleobiogeography". Paleontological Research. 1 (4): 311–315.
  32. ↑ Jiangzuo, Qigao; Li, Chunxiao; Zhang, Xiaoxiao; Wang, Shiqi; Ye, Je; Li, Yu (2020-02-07). "Diversity of Amphicyonidae (Carnivora, Mammalia) in the Middle Miocene Halamagai formation in Ulungur River area, Xinjiang, Northwestern China". Historical Biology. 32 (2): 187–202. doi:10.1080/08912963.2018.1477142. ISSN   0891-2963. S2CID   90842601.
  33. ↑ Qiu, Zhu-ding; Qiu, Zhan-xiang (2013-05-14), Chapter 4. Early Miocene Xiejiahe and Sihong Fossil Localities and Their Faunas, Eastern China, Columbia University Press, pp. 142–154, doi:10.7312/wang15012-004, ISBN   978-0-231-52082-9 , retrieved 2023-09-09


This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.