李刈昆. 甘肃临夏盆地晚中新世杨家山动物群的瞪羚化石[J]. 第四纪研究, 2015, 35(3): 550-560. doi: 10.11928/j.issn.1001-7410.2015.03.07
引用本文:
李刈昆. 甘肃临夏盆地晚中新世杨家山动物群的瞪羚化石[J]. 第四纪研究, 2015, 35(3): 550-560.
doi:
10.11928/j.issn.1001-7410.2015.03.07
李刈昆. 甘肃临夏盆地晚中新世杨家山动物群的瞪羚化石[J]. 第四纪研究, 2015, 35(3): 550-560. doi: 10.11928/j.issn.1001-7410.2015.03.07
Li Yikun. Gazella fossils of the Late Miocene Yangjiashan fauna from the Linxia Basin, Gansu Province[J]. Quaternary Sciences, 2015, 35(3): 550-560. doi: 10.11928/j.issn.1001-7410.2015.03.07
Citation:
Li Yikun. Gazella fossils of the Late Miocene Yangjiashan fauna from the Linxia Basin, Gansu Province[J].
Quaternary Sciences
, 2015, 35(3): 550-560.
doi:
10.11928/j.issn.1001-7410.2015.03.07
文章记述了甘肃临夏盆地晚中新世杨家山动物群的瞪羚(Gazella)化石, 将临夏材料归为保德瞪羚(Gazella paotehensis)、高氏瞪羚相似种(G. cf. gaudryi)和瞪羚未定种(G. sp.)。G. paotehensis为有效种, 与G. gaudryi 区别在于G. paotehensis两角心分散度大, 表面发育较深纵沟; 与G. dorcadoides区别在于G. paotehensis角心向后外方伸出角度较高, 侧视倾斜度小, 脑颅部从额顶缝开始呈弧形向后下方弯曲。依据临夏的瞪羚化石组合推测杨家山动物群的生活环境可能为温带开阔草原, 有灌木丛为典型食叶者食用。依据脑颅轮廓, G. paotehensis应归入短头型, 验证了G. paotehensis可能是G. blacki祖先的观点。
瞪羚(
Gazella
)
杨家山动物群
Abstract:
Fossils of Gazella unearthed from the Linxia Basin, Gansu Province are studied in this paper.The fossils localities, Baihuacun(LX0205,35°23'43.2"N, 103°29'45.2"E) and Shilei(LX0031, 35°25'19.7"N, 103°27'30.3"E), locate in Guanghe County, Linxia Hui Autonomous Prefecture, Gansu Province.The fossiliferous layers correspond to the upper part of the Late Miocene Liushu Formation, and the associated fauna is indentified as Yangjiashan fauna.Seven individuals, including six skulls, one horn core, two half-mandibles and stylohyoids, are described here and can be classified into Gazella paotehensis, Gazella cf.gaudryi and Gazella sp.three species.Although Gazella fossils are very common in the formations from Late Miocene to Pleistocene, previously reported materials are usually isolated teeth and horn cores or have undergone diagenetic deformations, especially for those from Late Miocene.Due to above reasons, Late Miocene gazelles are confusing in the classifications.The materials from the Linxia basin belong to G.gaudryi type, different from G.dorcadoides type in having mesodont teeth with ribs on the metacones of M1 and M2, and longer premolar rows.G.paotehensis is viewed as a valid species, which is a small-sized, short braincased Gazella, similar to G.gaudryi and G.dorcadoides in size.G.paotehensis differs from G.gaudryi in having more divergent horn cores with developed longitudinal grooves, G.paotehensis differs from G.dorcadoides in having less inclined horn cores in side view and more slowly curved down cranial roof from the frontal-parietal suture.The maximum width of the cross section at the horn base locates behind the middle in G.cf.gaudryi, which is different from that in G.gaudryi. The material identified as G.sp.differs from former two species in having more upright horn cores in side view and narrow braincase, which is similar to G.cf.lydekkeri from Lantian in shape, and similar to G.lydekkeri from Siwalik in size.Gansu was once thought to be open environments, which is typical for G.dorcadoides fauna, however, with the appearances of G.paotehensis and G. cf.gaudryi, the environment of Yangjiashan fauna can be interpreted as open steppe with bushes for typical browsers living.G.paotehensis can be placed in the evolutionary lineage of short braincased Gazella based on the characters of skull, teeth and hore corns, and thus G.paotehensis can be proved to be ancestry of G.blacki.
Key words:
Gazella
Linxia Basin
Late Miocene
Yangjiashan fauna