Thursday, January 11, 2007

 

A previously unrecognized group of Middle Jurassic triconodontan mammals from Central Asia

An open access article from Naturwissenschaften:

Abstract

Ferganodon narynensis gen. et sp. nov. is represented by a lower molariform tooth from the Middle Jurassic (Callovian) Balabansai Svita in Kyrgyzstan. The new genus is allied with Klamelia zhaopengi Chow and Rich 1984 from the Middle Jurassic Shishugou Formation in Xinjiang, northwest China to the new family Klameliidae based on parallelogram-shaped lower molariforms, imbricating rather than interlocking of cusps e-d-f, by a peculiar distolabial cingulid cusp, and by vertical folding of the enamel on the labial crown side. The new family Klameliidae fam. nov. is most similar to Gobiconodontidae by the structure of the molariform teeth and represents a previously unrecognized radiation of eutriconodontan mammals possibly endemic to Central Asia.

Introduction

There are three vertebrate localities within the Middle Jurassic Balabansai Svita in the northern Fergana Valley, Kyrgyzstan that have produced remains of mammals: (1) Sarykamyshsai 1 (site FTA-30), 3–4 km east of the town of Tashkumyr (lower, gray to greenish colored part of the Balabansai Svita, Callovian); (2) Tashkumyr 1 (site FTA-131), left bank of the Naryn River close to the town of Tashkumyr (bonebed within a calcareous sandstone of the lower part of the Balabansai Svita, Callovian); and (3) Dzhiddasai (site FBX-23), 5 km west of the town of Tashkumyr (upper, red colored part of the Balabansai Svita, Callovian; see Averianov et al. 2005 for a more detailed description of localities). More than 20 mostly fragmentary mammalian teeth were recovered so far from these localities. The mammal fauna is dominated by docodonts, represented by an isolated molar of Tashkumyrodon desideratus Martin and Averianov 2004 from Sarykamyshsai 1 and by a lower molar and several upper molar fragments of a new docodont from the Tashkumyr 1 bonebed that is similar to Dsungarodon zuoi Pfretzschner and Martin, 2005 from the Late Jurassic (Oxfordian) Qigu Formation in the Junggar Basin, Xinjiang, northwestern China. This locality produced also one almost complete and several fragmentary teeth referable to one or two taxa of Eutriconodonta. The most complete eutriconodontan tooth is described here and attributed to a new taxon within the newly established family Klameliidae fam. nov.

Continued via "A previously unrecognized group of Middle Jurassic triconodontan mammals from Central Asia" [Fossil]

Technorati: , , , , , , , , , , , , , , , , , , ,

Add to: CiteUlike | Connotea | Del.icio.us | Digg | Furl | Newsvine | Reddit | Yahoo


Comments: Post a Comment

Links to this post:

Create a Link



<< 'General Evolution News' Home