Hapalodectidae

Taxobox
name = Hapalodectids
fossil_range = Late Paleocene to Middle Eocene


image_caption = "Hapalodectes serus"
regnum = Animalia
phylum = Chordata
classis = Mammalia
ordo = †Mesonychia
familia = Hapalodectidae
familia_authority = (Szalay & Gould, 1966)
subdivision_ranks = Genera
subdivision = "Hapalodectes"
"Hapalorestes"
"Metahapalodectes"
"Lohoodon"
"Honanodon"

Hapalodectidae (literally "Soft Biters" "hapalos" = "soft, tender," "dêktês" = "biter") is an extinct family of relatively small-bodied (1–8 kg)cite journal | author = Gunnell, G.R. and P.D. Gingerich | year = 1989 | title = New hapalodectid "Hapalorestes lovei" (Mammalia, Mesonychia) from the early middle Eocene of northwestern Wyoming | journal = Contributions from the Museum of Paleontology, The University of Michigan | volume = 29 | issue = 15 | pages = 413–418 | url = http://hdl.handle.net/2027.42/48636] mesonychian placental mammals from the Paleocene and Eocene of North America and Asia.cite book | author = McKenna, M. C, and S. K. Bell | year = 1997 | title = Classification of Mammals Above the Species Level | publisher = Columbia University Press | id = ISBN 023111012X] Hapalodectids differ from the larger and better-known mesonychids in having teeth specialized for cutting (presumably meat), while the teeth of other mesonychids, such as "Mesonyx" or "Sinonyx", are more specialized for crushing bones. Hapalodectids were once considered a subfamily of Mesonychidae,cite journal | author = Szalay, F.S. and S.J. Gould | year = 1966 | title = Asiatic Mesonychidae (Mammalia, Condylarthra) | journal = Bulletin of the American Museum of Natural History | volume = 132 | issue = 2 | pages = 127–174 | url = http://hdl.handle.net/2246/1112] but the discovery of a skull of "Hapalodectes hetangensis" showed additional differences justifying placement in a distinct family.cite journal | author = Ting, S. and C. Li | year = 1987 | title = The skull of "Hapalodectes" (?Acreodi, Mammalia), with notes on some Chinese Paleocene mesonychids | journal = Vertebrata PalAsiatica | volume = 25 | issue = | pages = 161–186 | url = ] In particular, "H. hetangensis" has a postorbital bar closing the back of the orbit, a feature lacking in mesonychids. The skeleton of hapalodectids is poorly known and of the post-cranial elements, only the humerus has been described. The morphology of this bone indicates less specialization for terrestrial locomotion than in mesonychids.cite journal | author = O'Leary, M.A. | year = 1998 | title = Morphology of the humerus of "Hapalodectes" (Mammalia, Mesonychia) | journal = American Museum Novitates | volume = 3242 | issue = | pages = 1–6 | url = http://hdl.handle.net/2246/3175]

References