Bemalambdidae
{{short description|Extinct family of mammals}}
{{Automatic taxobox
| fossil_range = {{Fossil range|Early Paleocene|Middle Paleocene}}
| image = Skeleton of Bemalambda pachyoesteus.jpg
| image_caption = Skeleton of Bemalambda pachyoesteus, exhibited in the National Museum of Nature and Science, Tokyo, Japan.
| display_parents = 2
| taxon = Bemalambdidae
| authority = {{Harvnb|Chow|Chang|Wang|Ting|1973}}
| subdivision_ranks = Genera and species
| subdivision_ref = {{Paleodb|40560|Bemalambdidae}}. Retrieved July 2013.
| subdivision =
- {{Extinct}}Bemalambda (type)
{{Harvnb|Chow|Chang|Wang|Ting|1973}} - {{Extinct}}B. nanhsiungensis (type)
{{Harvnb|Chow|Chang|Wang|Ting|1973}} - {{Extinct}}B. pachyoesteus
{{Harvnb|Chow|Chang|Wang|Ting|1973}} - {{Extinct}}B. dingae
{{Harvnb|Li|2005}} - {{Extinct}}B. crassa
{{Harvnb|Chow|Chang|Wang|Ting|1973}} - {{Extinct}}Hypsilolambda
{{Harvnb|Wang|1975}} - {{Extinct}}H. chalingensis
{{Harvnb|Wang|1975}}
}}
Bemalambdidae is an extinct family of pantodont mammals known from Early and Middle Paleocene of China.
Description
The bemalambdids are, along with Harpyodus and Alcidedorbignya, the most primitive pantodonts. Hypsilolambda is known only from a skull and teeth, but Bemalambda is known from complete cranial and postcranial specimens and is the best preserved mammal from Shanghuan. It was dog-sized (a large animal for its era) and omnivorous.{{Harvnb|Lucas|2001|p=207}}
Both genera have dilambdodont upper premolars (W-shaped crests on the crowns), one of the characteristics of pantodonts, but their upper molars, unlike in later pantodonts, are almost zalambdodont (V-shaped crests) and transversely elongated with the paracone and metacone (cusp) appressed or connated. On p3-M3, there is a large buccal platform on the crowns, the stylar shelf. An exterior indentation on the buccal side, the ectoflexus, is very deep. The lower cheek teeth are easily recognizable as pantodont.{{Harvnb|Rose|2006|p=114}}
The bemalambdids had a low and short skull with a very small braincase; a prominent sagittal crest and deep temporal fossae, a broad snout; and flaring zygomatic processes. The high coronoid process on the mandible suggest the chewing musculatures was more developed than in later pantodonts. The postcranium was robust, and, judging from a single massive humerus, adapted for digging.
Fossil localities
- the Early Paleocene ({{Mya|65.5|58.7|Ma}}) of Guangdong, China (type) ({{Coord|25.1|114.3|display=inline}}, paleocoordinates {{Coord|26.0|109.4|display=inline}}){{Paleodb|collection|140280|Linnania type, Nanxiong (Paleocene to China)}}. Retrieved July 2013.
- the Early Paleocene (65.5 - 58.7 Ma) of Shaanxi, China{{Paleodb|collection|132651|Shimen Commune (lower bed) (Paleocene of China)}}. Retrieved July 2013.
- the Middle Paleocene (61.7 - 58.7 Ma) of Jiangxi, China{{Paleodb|collection|140276|300 m SW of Fengshuxia (Paleocene of China)}}. Retrieved July 2013.
Notes
{{Reflist}}
References
{{Refbegin}}
- {{Cite journal
| last1 = Chow | first1 = M. M.
| last2 = Chang | first2 = Y.-P.
| last3 = Wang | first3 = B.-Y.
| last4 = Ting | first4 = S.-Y.
| title = New mammalian genera and species from the Paleocene of Nanhsiung, N. Kwangtung | language = Chinese, English
| year = 1973 | journal = Vertebrata PalAsiatica | volume = 11 | issue = 1 | pages = 31–35
| url = http://www.ivpp.cas.cn/cbw/gjzdwxb/xbwzxz/200905/W020090813377871125687.pdf | access-date = 17 July 2013
}}
- {{Cite journal
| last = Li | first = Qian
| title = New Material of Bamalamdba from Chijiang Basin in Jiangxi, China | language = Chinese, English
| year = 2005 | journal = Vertebrata PalAsiatica | volume = 43 | issue = 4 | pages = 325–329
| url = http://www.ivpp.cas.cn/cbw/gjzdwxb/xbwzxz/200810/W020090813368813784923.pdf | access-date = 17 July 2013
}}
- {{Cite book
| last = Lucas | first = Spencer G.
| title = Chinese Fossil Vertebrates
| year = 2001 | publisher = Columbia University Press
| url = https://books.google.com/books?id=AzHUXy7HGo4C&pg=PA207 | access-date = 17 July 2013
| isbn = 9780231504614 }}
- {{Cite book
| last = Rose | first = Kenneth David
| title = The beginning of the age of mammals
| year = 2006 | publisher = JHU Press | location = Baltimore
| url = https://books.google.com/books?id=3bs0D5ix4VAC
| isbn = 0801884721 }}
- {{Cite journal
| last = Wang | first = Banyue
| title = Paleocene mammals of Chaling Basin, Hunan | language = Chinese
| year = 1975 | journal = Vertebrata PalAsiatica | volume = 13 | issue = 3 | pages = 154–62
| url = http://www.ivpp.cas.cn/cbw/gjzdwxb/xbwzxz/200905/W020090813377308964659.pdf | access-date = 17 July 2013
}}
{{Refend}}
{{Pantodonta}}
{{Taxonbar|from=Q15839257}}
Category:Paleocene first appearances