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古脊椎动物学报 ›› 2012, Vol. 50 ›› Issue (3): 293-307.

• 古脊椎动物学报 • 上一篇    

生物古地理、分子分异时间及化石纪录:古中华貂在内蒙古阿巴嘎旗晚中新世宝格达乌拉组的新材料

王晓鸣,曾志杰,竹内哲二   

  • 出版日期:2012-09-15 发布日期:2012-09-15

ZOOGEOGRAPHY, MOLECULAR DIVERGENCE, AND THE FOSSIL RECORD – THE CASE OF AN EXTINCT FISHER, PEKANIAPALAEOSINENSIS (MUSTELIDAE, MAMMALIA), FROM THE LATE MIOCENE BAOGEDA ULA FORMATION, NEI MONGOL

WANG Xiao-Ming, Zhijie Jack TSENG, Gary T. TAKEUCHI   

  • Published:2012-09-15 Online:2012-09-15

摘要: 北美现生的潘氏貂Martes pennanti (荷兰殖民区俗名fisher,北美印地安土著俗名pekan)传统被归入貂属(Martes)。20世纪70年代初Elaine Anderson首先认识到北美fisher的祖先可以追溯到中国山西保德晚中新世的古中华貂M. palaeosinensis。它们的共同特征是上裂齿唇侧具有一个孤立的小齿根。因此在众多的化石和现生貂中,这些具有多一个小齿根的种类可以归入它们自己的一个分支,并重新启用已建立的Pekania属来区别于其他种类。近年来新兴的分子系统研究也趋于把北美的fisher与中、南美的Eira及北半球的狼獾(Gulo)并列,甚至指示它可能是狼獾的姊妹群。因此把fisher独立归入Pekania属中可能是未来的方向。2009年我们在内蒙古阿巴嘎旗宝格达乌拉组的晚中新世地层中发现了一个古中华貂的上颌。这是该种在内蒙古的首次发现,借此机会对目前的分子系统关系、分异年代及化石记录进行综合探讨。虽然保德和宝格达乌拉的古中华貂在时代上与分子钟估算的5~8 Ma比较一致,狼獾的化石记录却远比古中华貂的老(可以追到11 Ma左右)。如果狼獾确实是fisher的姊妹群或与它并系的话,那么fisher的分异时间也可能更早。

Abstract: Elaine Anderson first established in the early 1970s a close relationship between the late Miocene Chinese Martes palaeosinensis and living North American fisher M. pennanti, based on their shared presence of an external rootlet on the upper carnassial. Such a recognition paved the way for their elevated status as a distinct genus of their own, Pekania, an implicit relationship increasingly corroborated by molecular phylogenetics, which tend to show that the living fisher is either a sister to the northern Holarctic wolverine (Gulo) or a stem group bracketed between Central and South American tayra (Eira) and a Gulo-Martes clade. We describe an upper jaw ofPekania palaeosinensis from the late Miocene (Baodean) Baogeda Ula Formation of Nei Mongol. We take this opportunity to review the molecular relationships, divergence time, and the fossil record of the Pekania clade. Although the Chinese records of the fishers are in close agreement with divergence time estimates of 5−8 Ma for the Pekania clade based on molecular clock estimates, a deep fossil record for the wolverines, on the other hand, suggests a much more ancient divergence time and by extension, for the fishers as well.