...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Experimental Botany >Hunting the Snark: the flawed search for mythical Jurassic angiosperms
【24h】

Hunting the Snark: the flawed search for mythical Jurassic angiosperms

机译：狩猎Snark：对神秘的侏罗纪神经植物有缺陷的搜索

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Several recent palaeobotanical studies claim to have found and described pre-Cretaceous angiosperm macrofossils. With rare exceptions, these papers fail to define a flower, do not acknowledge that fossils require character-based rather than group-based classification, do not explicitly state which morphological features would unambiguously identify a fossil as angiospermous, ignore the modern conceptual framework of phylogeny reconstruction, and infer features in the fossils in question that are interpreted differently by (or even invisible to) other researchers. This unfortunate situation is compounded by the relevant fossils being highly disarticulated two-dimensional compression-impressions lacking anatomical preservation. Given current evidence, all supposed pre-Cretaceous angiosperms are assignable to other major clades among the gymnosperms sensu lato. By any workable morphological definition, flowers are not confined to, and therefore cannot delimit, the angiosperm Glade. More precisely defined character states that are potentially diagnostic of angiosperms must by definition originate on the phylogenetic branch that immediately precedes the angiosperm crown group. Although the most reliable candidates for diagnostic characters (triploid endosperm reflecting double fertilization, closed carpel, bitegmic ovule, and phloem companion cells) are rarely preserved and/or difficult to detect unambiguously, similar characters have occasionally been preserved in high-quality permineralized non-angiosperm fossils. The angiosperm radiation documented by Early Cretaceous fossils involves only lineages closely similar to extant taxonomic families, lacks obvious morphological gaps, and (as agreed by both the fossil record and molecular phylogenies) was relatively rapid-all features that suggest a primary radiation. It is unlikely that ancestors of the crown group common ancestor would have fulfilled a character-based definition of (and thereby required expansion of the concept of) an angiosperm; they would instead form a new element of the non-angiosperm members of the 'anthophyte' grade, competing with Caytonia to be viewed as morphologically determined sister group for angiosperms. Conclusions drawn from molecular phylogenetics should not be allowed to routinely constrain palaeobotanical inferences; reciprocal illumination between different categories of data offers greater explanatory power than immediately resorting to Grand Syntheses. The Jurassic angiosperm-essentially a product of molecular phylogenetics-may have become the holy grail of palaeobotany but it appears equally mythical.
机译：最近近几项古生物研究要求发现并描述了白垩纪的高钙培培巨乳。由于罕见的例外，这些论文未能定义一朵花，不承认化石需要基于角色而不是基于组的分类，没有明确地说明哪种形态特征将毫不含糊地识别化石，以吸引性，忽略了系统发育的现代概念框架重建，和推断出来的化石中的特征，被其他研究人员解释为不同的（甚至是不可见的）。这种不幸的情况是由相关化石复杂化的高度缺乏解剖保存的高度释放的二维压缩印象。鉴于目前的证据，所有假设的白垩纪被子培养物可分配到裸子植物Sensu Lato之间的其他主要曲线。通过任何可行的形态定义，鲜花不限于，因此无法分隔，即时普遍存在。更精确定义的具有潜在诊断的心血管诊断的特征状态必须根据定义来源于动解枝，该分支立即前后冠组。尽管诊断性质最可靠的候选者（反映双施肥的三倍体胚乳，闭合的胚胎，卵形胚珠和韧皮伴侣细胞）很少被保存和/或难以毫不含糊地检测，但偶尔已经保留了高质量的禁止态贪眼化石。由早期白垩纪化石记录的高原辐射涉及只与现时的分类家庭密切相关的谱系，缺乏明显的形态间隙，并且（如化石记录和分子系统的商定）相对较快 - 建议初级辐射的所有功能。皇冠集团共同祖先的祖先不太可能满足基于角色的定义（从而所要求的概念的概念）;它们将形成“植物病”成绩的非高昂成员的新因素，与Caytonia竞争，以被视为心理学确定的Anviosperms的姐妹组。不应使来自分子系统的结论常规限制古生物推论;不同类别的数据之间的互惠照明提供比立即诉诸大合成的更大的解释力。侏罗纪贪眼 - 基本上是分子系统发育的产物 - 可能已成为甘蓝族的圣杯，但它看起来同样神话。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号