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Hapalodectidae

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Hapalodectidae
Temporal range: Late Paleocene–Late Eocene
Life restoration of Hapalodectes serus (bottom) and Pachyaena
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Mesonychia
Family: Mesonychidae
Szalay & Gould, 1966
Genera

Hapalodectidae (literal translation 'soft biters': hapalos ('soft, tender'), dêktês ('biter')) is an extinct family of relatively small-bodied (1–8 kg (2.2–17.6 lb))[1] mesonychian placental mammals from the Paleocene and Eocene of North America and Asia.[2] Hapalodectids differ from the larger and better-known mesonychids by having teeth specialized for cutting (presumably meat), while the teeth of other mesonychids, such as Mesonyx or Sinonyx, are more specialized for crushing bones.[1] Hapalodectids were once considered a subfamily of the Mesonychidae,[3] but the discovery of a skull of Hapalodectes hetangensis showed additional differences justifying placement in a distinct family.[4] In particular, H. hetangensis has a postorbital bar closing the back of the orbit,[4] a feature lacking in mesonychids. The postcranial skeletal anatomy of hapalodectids is poorly known, and of the postcranial elements, only the humerus has been described. The morphology of this bone indicates less specialization for terrestrial locomotion than in mesonychids.[5]

Taxa

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"Hapalodectinae" was originally erected on the basis of Hapalodectes, and, after promotion to family ranking, contained up to five genera based on teeth and jaw fragments with anatomies similar to Hapalodectes. However, as of Ting and Li, 1987, and confirmed with Gunnell and Gingerich, 1996, the genera Honanodon, Lohoodon and Metahapalodectes are no longer considered hapalodectids due to the absence of grooves on the lower molars otherwise diagnostic of Hapalodectes and Hapalorestes.[6]

Family Hapalodectidae

  • Genus Hapalodectes
    • H. anthracinus Zhou et Gingerich, 1991
    • H. dux Lopatin, 1999
    • H. hetangensis Ting et Li, 1987
    • H. huanghaiensis Tong et Wang, 2006
    • H. leptognathus Osborn et Wortman, 1892
    • H. lopatini Solé et al., 2017
    • H. paleocenus Beard et al., 2010
    • H. serus Matthew et Granger, 1925
  • Genus Hapalorestes
    • H. lovei

References

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  1. ^ a b Gunnell, Gregg F.; Gingerich, Philip D. (1989). "New hapalodectid Hapalorestes lovei (Mammalia, Mesonychia) from the early middle Eocene of northwestern Wyoming". Contributions from the Museum of Paleontology. 29 (15). University of Michigan: 413–418. hdl:2027.42/48636.
  2. ^ McKenna, Malcolm C.; Bell, Susan K. (December 1997). Classification of Mammals Above the Species Level. Columbia University Press. ISBN 0-231-11012-X.
  3. ^ Szalay, Frederick S.; Gould, Stephen Jay (1966). "Asiatic Mesonychidae (Mammalia, Condylarthra)". Bulletin of the American Museum of Natural History. 132: 127–174. hdl:2246/1112.
  4. ^ a b Ting, Suyin; Li, Chuankuei (1987). "The skull of Hapalodectes (?Acreodi, Mammalia), with notes on some Chinese Paleocene mesonychids" (PDF). Vertebrata PalAsiatica (in Chinese and English). 25: 161–186. Archived (PDF) from the original on 2020-11-02.
  5. ^ O'Leary, Maureen A. (1998). "Morphology of the humerus of Hapalodectes (Mammalia, Mesonychia)". American Museum Novitates (3242): 1–6. hdl:2246/3175.
  6. ^ Gunnell, Gregg F., and Philip D. Gingerich. "New hapalodectid Hapalorestes lovei (Mammalia, Mesonychia) from the early Middle Eocene of northwestern Wyoming." (1996).