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Post by brobear on Feb 22, 2019 14:32:51 GMT -5
Agriotherium species:
1 - †A. myanmarensis (Ogino et al., 2011)
2 - †A. insigne (Gervais, 1859)
3 - †A. inexpetans (Qiu et al., 1991)
4 - †A. palaeindicus (Lydekker, 1878)
5 - †A. sivalensis (Falconer & Cautley, 1836)
6 - †A. africanum (Hendey, 1972)
7 - †A. coffeyi (Dalquest, 1986)
8 - †A. gregoryi (Frick, 1926)
9 - †A. schneideri (Sellards, 1916)
10- Agriotherium hendeyi
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Post by brobear on Mar 6, 2019 18:01:17 GMT -5
Here we describe a new species of giant short-faced fossil bears, Agriotherium myanmarensis sp. nov. (Ursidae, Carnivora), from the latest Miocene to early Pliocene Irrawaddy sediments in the Chaingzauk area, central Myanmar. A. myanmarensis has a short mandible and a deep premasseteric fossa, both of which are the typical feature of Agriotherium. There are two specimens discovered so far: in the type specimen the inferior border of the mandibular corpus is rectilinearly-shaped, the m1 talonid is rather reduced, m1 metaconid larger than the entoconid–entoconulid ridge, the diastema between canine and p4 is very short, and the postcanine teeth are so reduced that existing cheek teeth are very crowded. Agriotherium had been widely distributed from the late Miocene through Pleistocene in Europe, East Asia (China), North America, and South Africa, but no fossil record has been reported from Southeast Asia. Except its extreme short snout, A. myanmarensis is most similar to that of the European form, Agriotheriuminsigne, rather than to the Asian species from Siwalik or China, such as Agriotherium palaeindicus, Agriotherium sivalensis, and Agriotherium inexpetans, suggesting the phylogenetic closeness to the European rather than to the South/East Asian forms. Shintaro Ogino; Naoko Egi; Zin-Maung-Maung-Thein; Thaung-Htike; Masanaru Takai (2011).New species of Agriotherium (Mammalia, Carnivora) from the late Miocene to early Pliocene of central Myanmar. Journal of Asian Earth Sciences, 42 (3), pg. 408-414. www.sciencedirect.com/science/article/pii/S1367912011002185 shaggygod.proboards.com/  |
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Post by King Kodiak on Feb 28, 2020 18:11:05 GMT -5
AGRIOTHERIUM SIVALENSIS 
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Post by King Kodiak on Mar 13, 2020 17:11:56 GMT -5
New Species of Agriotherium from North America, and Implications for Understanding Transformations in the Metaconid-Entoconid Complex of Bears
New material of Agriotherium from the late Hemphillian (~6 Ma) Quiburis Formation in Arizona, North America is reported. These specimens represent a new species, Agriotherium hendeyi, sp. nov., of small size and with a bucco-lingually narrow lower dentition distinguishing it from North American “Agriotherium” schneideri as well as the genotype and other Old World species of Agriotherium. Strikingly, the m1 metaconid-entoconid complex of the new species exhibits a morphologically transitional state between the pattern observed in Indarctos (three cusps) and the typical Agriotherium pattern (two cusps). Together with a review of the variation in A. africanum, a geometric morphometric analysis permits identification and discussion of a proposed transformation pathway from the Indarctos pattern to the Agriotherium pattern. It is shown that the two cusps in the metaconid-entoconid complex in Agriotherium correspond to the two entoconids in Indarctos, whereas the ancestral metaconid is reduced or lost in Agriotherium. From a developmental perspective, the metaconid fused to the anterior entoconid as a result of the shortening of the talonid, rather than via replacement of the metaconid by a posterior shift of the entoconid, presumably under selective pressure towards a more typically hypercarnivorous tooth morphology and carnivorous diet.
www.researchgate.net/publication/335276057_A_New_Species_of_Agriotherium_from_North_America_and_Implications_for_Understanding_Transformations_in_the_Metaconid-Entoconid_Complex_of_Bears
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Post by King Kodiak on Sept 6, 2020 11:00:38 GMT -5
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Post by brobear on Sept 6, 2020 14:21:37 GMT -5
*Nice find King Kodiak. According to our findings here, it appears that Agriotheriums were hypercarnivorous bears.
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Post by brobear on Dec 13, 2020 8:20:31 GMT -5
There is strong disagreement among paleontologists of where Agriotherium was a bear or a dog-bear - Hemicyonidae.
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Post by King Kodiak on Dec 15, 2020 16:10:58 GMT -5
Agriotherium schneideri from the Hemphillian of Central Mexico
Abstract and Figures
A well-preserved upper and lower dentition of Agriotherium schneideri from the late Tertiary of Guanajuato, Mexico, permits a better understanding of this poorly known bear. Other North American species have been assigned to this genus, but only A. schneideri is here considered valid. Despite scant material, it appears that this ursid displayed a wide range of variability in its dentition. Paucity of specimens indicates that Agriotherium and its contemporary, Indarctos, were less common in the New World than in the Old World. True carnassials and massive, potentially bone-crushing cheekteeth imply that both genera were active predator-scavengers rather than more passive omnivores with a mostly herbivorous diet. The brief geologic time range of Agriotherium in North America makes it a useful biochronologic marker, albeit on a limited basis due to scarcity of specimens.
Full report here:
www.researchgate.net/publication/272595545_Agriotherium_schneideri_from_the_Hemphillian_of_Central_Mexico
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Post by brobear on Dec 15, 2020 20:06:33 GMT -5
by Homero13.  |
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Post by OldGreenGrolar on Dec 15, 2020 20:13:01 GMT -5
These short faced bears were definitely one of the most numerous bears.
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Post by brobear on Dec 16, 2020 5:10:36 GMT -5
These short faced bears were definitely one of the most numerous bears. The Tremarctinae ( short-faced bears ) were numerous in North and South America, but never spread any further. The Agriotheriinae were much more numerous. |
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Post by OldGreenGrolar on Dec 16, 2020 6:48:52 GMT -5
/\ Care to list the continents the Agrioteriums were present in ?
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Post by brobear on Dec 16, 2020 6:55:59 GMT -5
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Post by OldGreenGrolar on Dec 16, 2020 7:25:41 GMT -5
Thank you. The Agrioterium must surely have encountered cave bears, Atlas bears, brown bears, and Asiatic black bears. |
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Post by brobear on Dec 16, 2020 8:53:54 GMT -5
en.wikipedia.org/wiki/Agriotherium Agriotherium is an extinct genus of bears whose fossils are found in Miocene through Pleistocene-aged strata of North America, Europe, Africa, and Asia. This long-lived genus persisted from at least ~11.6–2.5 Mya. Materials from the late-surviving A. africanum in Africa have suggested that A. africanum died out during the early Gelasian. *TheGreenAgriotherium... how many of those animals you listed were around two and a half million years ago when the last Agriotherium died?
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