南京大学等发表最新《自然》文章

　　

生物通报道：来自美国自然历史卡内基博物馆（Carnegie Museum of Natural History），南京大学地球科学系，以及中科院南京地质与古生物研究所现代古生物学和地层学国家重点实验室（State Key Laboratory of Palaeobiology and Stratigraphy）的研究人员通过在河北省北部发现的一中生代eutriconodont(Yanoconodon allini)，提出中耳骨（middle ear bones）是由一Meckel软骨与下颚骨相连的，这为研究早期哺乳动物Hox基因作用模式提供了重要依据。这一研究成果公布在3月15日《Nature》杂志上。

文章的第一作者与通讯作者为来自美国自然历史卡内基博物馆古脊椎动物分部的馆长罗哲西博士，其早年毕业于南京大学，现为南京大学的客座教授，参予这一研究的还包括陈丕基（Peiji Chen，音译），李罡（Gang Li，音译），陈萌（Meng Chen，音译）。

原文摘要：
Nature 446, 288-293 (15 March 2007) | 
doi:10.1038/nature05627; Received 4 August 2006; Accepted 29 January 2007
A new eutriconodont mammal and evolutionary development in early mammals  [Abstract]

来自于爬虫类下颚骨（reptilian mandible）的三块小中耳骨(middle ear bones)的拆分是现代哺乳动物的一个重要进化，因此相关的研究也就受到了古生物学家，进化生物学家等的关注，在去年的一篇研究报告中，研究人员对潘氏鱼（Panderichthys）——与最早出现在陆地上的四足动物具有同一个祖先、且同时进化的一种古鱼——的头骨化石进行了分析，并将它的头骨和脑部结构与一种更古老的鱼类化石以及一种早期四足动物化石进行了比对，结果发现潘氏鱼的骨柱开始显现出镫骨的模样，而中耳骨正是由此而来，这一文章同样发表于《Nature》杂志。

而在这篇文章中，罗博士等人则进一步通过冠群哺乳动物（crown mammals）的一Mesozoic eutriconodont发现了中耳骨的演变历程：经由一骨化的Meckel软骨，中耳骨与下颚骨相连。这种相连耳朵和颚骨的结构与现代单孔类动物（monotremes，egg-laying mammals）以及胎盘哺乳动物的胚胎模式相似，但是在成体中仍然保持着，属于幼形遗留（paedomorphic feature），与单孔类动物和胎盘动物成体并不相同。

(New mammal Yanoconodon allini，图片来自Nature）

这说明这种哺乳动物前（premammalian）祖先环境的逆转或者维持是与不同的发育时期相关的，要么“现代的”中耳独立演化过两次，要么它曾经涉及过至少一个古代分支、然后又在它们身上消失了。这一新eutriconodont也增加了thoraco-lumbar转变的脊椎特征同型，以及早期哺乳动物未融合腰肋（lumbar ribs）的证据。而这与现代哺乳动物椎骨中homeobox基因模式效应相似，从而为研究Hox基因模式提供了新的切入口。
（生物通：张迪）

附：
罗哲西博士

Post-doctoral Fellow, 1989-91, Harvard University
Ph.D., 1989, University of California at Berkeley
B.S., 1982, Nanjing University (China) 

Phone: [phone] 
Fax: [phone] 
Email: [e-mail]

General Research Interests: 

- Vertebrate Paleontology 
- Evolutionary Morphology of Vertebrates 
- Systematic Biology 

Research Projects:

Evolution of Hearing in Whales: Evolution of ear structures and hearing specializations in toothed whales and baleen whales. 
Early Fossil Mammals: Their phylogenetic relationships and morphological evolution. 
Triassic–Jurassic Faunas: Vertebrate faunal transition from the Triassic to the Jurassic. 
Recent Publications:

Ji, Q., Z.-X. Luo, C.-X. Yuan, and A. R. Tabrum. 2006. A swimming mammaliaform from the Middle Jurassic and ecomorphological diversification of early mammals. Science 311: 1123-1127. E-print (376 Kb PDF) (supporting online material available via Science Web site) 

Li, G., and Z.-X. Luo. 2006. A Cretaceous symmetrodont therian with some monotreme-like postcranial features. Nature 439:195-200. E-print (772 Kb PDF) (supporting online material available via Nature Web site) 

Luo, Z.-X., and J. R. Wible. 2005. A Late Jurassic digging mammal and early mammalian diversification. Science 308:103-107. E-print (489 Kb PDF) (supporting online material available via Science Web site) 

Kielan-Jaworowska, Zofia, Richard L. Cifelli, & Zhe-Xi Luo. 2004. Mammals from the Age of Dinosaurs - Origins, Evolution, and Structure. Columbia University Press, New York. Pp. i-xv; 1-630. (More information is available on the Web site for Columbia University Press) 

Luo, Z.-X., Q. Ji, J. R. Wible and C-X. Yuan. 2003. An Early Cretaceous Tribosphenic mammal and metatherian evolution. Science 302:1934-1940. E-print (3.7 Mb PDF) (supporting online material available via Science Web site) 

Luo, Z.-X., Z. Kielan-Jaworowska, R. L. Cifelli. 2002. In Quest for A Phylogeny of Mesozoic Mammals. Acta Palaeontologica Polonica. 47(1): 1-78. E-print (3.6 MB PDF) (Supplementary Information: Data Matrix (25 Kb .mtx file) & PAUP Search Results (23 Kb .log file)) 

Ji, Q., Z.-X. Luo, C-X. Yuan, J. R. Wible, J.-P. Zhang, & J. A. Georgi. 2002. The earliest known eutherian mammal. Nature 416: 816-822. E-print (757 Kb PDF) (supplementary information available via Nature Web site) 

Luo, Z.-X. 2001. Inner ear and its bony housing in tritylodonts and implications for evolution of mammalian ear. Pp. 81-97. In: F. A. Jenkins et al. (eds.), Studies in Organismic and Evolutionary Biology in Honor of A. W. Crompton. Bulletin of Museum of Comparative Zoology, Harvard University. 156(1): 81-97. 

Luo, Z.-X., A. W. Crompton and A-L. Sun. 2001. A new mammaliaform from the Early Jurassic of China and evolution of mammalian characteristics. Science 292: 1535-1540. E-print (supporting online material available via Science Web site) 

Luo, Z.-X., R. C. Cifelli and Z. Kielan-Jaworowska. 2001. Dual evolution of tribosphenic mammals. Nature 409: 53-57. E-print (supplementary information available via Nature Web site) 

Tang, F., Z.-X. Luo, Z.-H. Zhou, H.-L. You, J. A. Georgi, Z.-L. Tang, and X.-Z. Wang. 2001. Biostratigraphy and Paleoenvironment of the Dinosaur-bearing Sediments in Lower Cretaceous of Mazongshan Area, Gansu Province, China. Cretaceous Research 22: 115-129. E-print (1.5 Mb PDF) 

Luo, Z.-X. 2000. Evolution: in search of the whales’ sisters. Nature 404: 235 - 239. E-print (241 Kb PDF) 

Luo, Z.-X. and P. D. Gingerich. 1999. Transition from terrestrial ungulates to aquatic whales: transformation of the basicranium and evolution of hearing. Papers on Paleontology (Monograph) 31: 1-98. Museum of Paleontology, University of Michigan, Ann Arbor, Michigan. 

Ji, Q., Z.-X. Luo, and S. Ji. 1999. A Chinese triconodont mammal and mosaic evolution of mammalian skeleton. Nature 398:326-330. E-print (supplementary information available via Nature Web site) 

Geisler, J. H., and Z.-X. Luo. 1998. Cranial vascular evolution in mesonychids and cetaceans and the phylogenetic position of cete. Pp. 161-212. In: J. G. M. Thewissen (ed.), Evolutionary Emergence of Whales. Plenum Press, New York. 

Luo, Z.-X., and K. Marsh. 1996. Petrosal (periotic) and inner ear of a Pliocene kogiine whale (Kogiinae, Odontoceti): Implications on relationships and hearing evolution of toothed whales. Journal of Vertebrate Paleontology 16:328–348. 

Luo, Z.-X., and E. R. Eastman. 1995. The petrosal and inner ear structures of a squalodontoid whale: Implications for evolution of hearing in odontocetes. Journal of Vertebrate Paleontology 15:431–422. 

Luo, Z.-X., and A.W. Crompton. 1994. Transformations of the quadrate (incus) through the transition from non-mammalian cynodonts to mammals. Journal of Vertebrate Paleontology 14:341–374. 


Luo, Z.-X. 1994. Sister taxon relationships of mammals and the transformations of the diagnostic mammalian characters. Pp. 98-128 in: In the Shadow of Dinosaurs-Early Mesozoic Tetrapods (N. C. Fraser & H.-D. Sues, eds.). Cambridge University Press.