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393:. This difference mirrors the history of the mammals classified as arctocyonids. They were first considered creodonts (imagined to be the ancestors of modern carnivores), and then "condylarths," (imagined to be the ancestors of hoofed mammals). Modern studies suggest the confusion is due to the fact that ungulates, carnivores, and creodonts are related groups, and flesh-eating lineages and adaptations evolved within each of them.
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body size) and the neocortex was less developed than later mammals. By the standards of modern mammals, they would have been neither especially quick nor intelligent, but their brains were comparable to many mammals of their time. Derived features of the inner ear were shared with fossils that are assigned to
354:
suggest these animals depended more on their sense of smell than sight, may have been able to hear about as well as a modern aardvark, and were slow-moving to moderately agile. The encephalization quotient (EQ) had a range of 0.12–0.41 (1.0=average brain size compared with modern mammals of a similar
323:, though they were not closely related to any living mammal. Well preserved fossils allow clear information on what they looked like. They were about 1 metre (3.3 ft) long including a long, robust tail, which may or may not have been
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499:"Virtual endocranial and inner ear endocasts of the Paleocene 'condylarth' Chriacus: new insight into the neurosensory system and evolution of early placental mammals"
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327:. Other features include a light build, weighing approximately 7 kg (15 lb), and many adaptations typical of animals that live in trees. These include
497:
Bertrand, Ornella C., Sarah L. Shelley John R. Wible Thomas E. Williamson Luke T. Holbrook
Stephen G.B. Chester Ian B. Butler, and Stephen L. Brusatte (2019).
335:. The powerfully built limbs had flexible joints, especially the ankles, an adaptation that allows an animal to turn its hind feet behind it, like modern tree
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359:(artiodactyls+perissodactyls), suggesting the genus may be close to the origin of ungulates, though it is too different in form to be a direct ancestor.
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783:
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in relation to other groups is disputed. Halliday et al. (2015) consider it a member of the family
Oxyclaenidae, a sister group to
635:"A structural intermediate between triisodontids and mesonychians (Mammalia, Acreodi) from the earliest Eocene of Portugal"
367:
There are nine species currently recognized in the genus. Like most early placental mammals, the classification of
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epoch and died out after the early Eocene. In life, members of the genus would have looked something like a
690:"Resolving_the_higher-level_phylogenetic_relationships_of_Triisodontidae_'Condylarthra'_within_Placentalia"
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419:"Climbing adaptations in the early eocene mammal Chriacus and the origin of artiodactyla"
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Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals
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Tabuce, Rodolphe; Clavel, Julien; Telles
Antunes, Miguel (2011-02-01).
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Shelley, Sarah L, Stephen L Brusatte, and Thomas E Williamson (2015).
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Halliday, Thomas J. D.; Upchurch, Paul; Goswami, Anjali (2015).
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572:""Resolving the relationships of Paleocene placental mammals""
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of their five-toed feet, and having long, curved, compressed
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lies somewhere within the range of their early relatives.
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311:that lived in what is now North America during the
725:Technical information in the Paleobiology database
346:Analysis of casts of the brain and inner ear from
343:, eating fruit, eggs, insects and small mammals.
339:, in order to climb downward. They were probably
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843:Paleocene mammals of North America
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307:is an extinct genus of placental
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848:Eocene mammals of North America
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853:Fossil taxa described in 1883
858:Prehistoric placental genera
741:reconstructed from skeletons
720:Article on Paleocene mammals
32:Early Paleocene–Early Eocene
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417:Rose, K. D. (1987-04-17).
659:10.1007/s00114-010-0747-y
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119:Scientific classification
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472:Palmer, D., ed. (1999).
16:Extinct genus of mammals
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443:10.1126/science.3426662
810:Paleobiology Database
389:, and allied to the
329:walking on the soles
651:2011NW.....98..145T
435:1987Sci...236..314R
112:Life reconstruction
576:Biological Reviews
503:Journal of Anatomy
348:Chriacus pelvidens
229:Chriacus pelvidens
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752:Taxon identifiers
588:10.1111/brv.12242
516:10.1111/joa.13084
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381:Loxolophus,
352:C. baldwini
269:C. katrinae
263:C. gallinae
251:C. baldwini
245:C. badgleyi
179:Arctocyonia
832:Categories
401:References
391:Mesonychia
357:Euungulata
325:prehensile
293:C. punitor
543:204969130
451:0036-8075
386:Arctocyon
377:Creodonts
341:omnivores
337:squirrels
321:binturong
313:Paleocene
142:Kingdom:
136:Eukaryota
775:Q2398857
769:Wikidata
760:Chriacus
739:Chriacus
702:cite web
675:22526630
667:21181109
606:28075073
535:31667836
395:Chriacus
369:Chriacus
317:kinkajou
304:Chriacus
236:Species
206:Chriacus
185:Family:
166:Mammalia
156:Chordata
152:Phylum:
146:Animalia
132:Domain:
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309:mammals
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383:then
333:claws
784:GBIF
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663:PMID
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531:PMID
478:ISBN
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447:ISSN
375:and
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212:Cope
37:PreꞒ
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