有角恐龙是东亚和北美西部白垩纪晚期特色鲜明的动物,通常被认为是那些地区的本地动物。有迹象表明,有角恐龙也可能出现在其他地方,但此前一直没有确凿的证据。在今天匈牙利所在地方一个有角恐龙新种的发现表明,白垩纪晚期的生物地理仍有让人们吃惊的东西有待发现。
当时欧洲大部分地方是一个群岛,在非洲和欧亚大陆块之间。虽然人们对其认识还很有限,但它仍有可能产生关于恐龙生物地理分布的相关信息。
中国科学员古脊椎动物与古人类研究所徐星研究员的一篇评述文章,对同期发表的一个欧美科学家小组有关新发现于匈牙利的角龙化石及其生物地理意义的研究成果进行了评述。这是徐星研究员应《自然》杂志编辑Tim Lincoln博士的邀请,发表在“新闻与观点”栏目的短文。“新闻与观点”栏目是《自然》杂志最流行的栏目,一般邀请常为《自然》审稿的专家对同期发表于《自然》杂志上较为重要或者能够引起大众兴趣的科研论文进行简介,并指出研究成果的局限性和相关研究的未来方向。
徐星在文章中指出,?si博士等人报道的新角龙类化石确实对于白垩纪晚期动物地理学研究具有重要意义,对于作者提出的发现于匈牙利的角龙可能是通过欧洲岛链,穿越古特提斯洋,从亚洲迁徙到欧洲的观点表示赞同。但是,徐星研究员认为,由于已知化石材料有限,匈牙利角龙的系统发育位置存在不确定性;而且,整个角龙家族的系统发育研究还有待深化,所以,作者有关匈牙利角龙的亚洲来源说虽然最有可能,但也不能完全排除北美来源说。
徐星表示,欧洲的独特地理位置决定了它在全球白垩纪晚期动物地理学研究方向的重要性,因此研究者将来应该更多地关注欧洲白垩纪晚期的陆相动物化石。(生物谷Bioon.com)
生物谷推荐原文出处:
Nature doi:10.1038/nature09019
A Late Cretaceous ceratopsian dinosaur from Europe with Asian affinities
Attila ?si,Richard J. Butler& David B. Weishampel
Ceratopsians (horned dinosaurs) represent a highly diverse and abundant radiation of non-avian dinosaurs1, 2, 3, 4, 5 known primarily from the Cretaceous period (65–145 million years ago). This radiation has been considered to be geographically limited to Asia and western North America1, 2, 3, with only controversial remains reported from other continents. Here we describe new ceratopsian cranial material from the Late Cretaceous of Iharkút, Hungary6, from a coronosaurian ceratopsian, Ajkaceratops kozmai. Ajkaceratops is most similar to ‘bagaceratopsids’ such as Bagaceratops and Magnirostris, previously known only from Late Cretaceous east Asia3, 5, 7, 8. The new material unambiguously demonstrates that ceratopsians occupied Late Cretaceous Europe and, when considered with the recent discovery of possible leptoceratopsid teeth from Sweden9, indicates that the clade may have reached Europe on at least two independent occasions. European Late Cretaceous dinosaur faunas have been characterized as consisting of a mix of endemic ‘relictual’ taxa and ‘Gondwanan’ taxa, with typical Asian and North American groups largely absent10, 11. Ajkaceratops demonstrates that this prevailing biogeographical hypothesis is overly simplified and requires reassessment. Iharkút was part of the western Tethyan archipelago, a tectonically complex series of island chains between Africa and Europe12, and the occurrence of a coronosaurian ceratopsian in this locality may represent an early Late Cretaceous ‘island-hopping’ dispersal across the Tethys Ocean.