• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Systematic Palaeontology >Node age estimations and the origin of angel sharks, Squatiniformes (Neoselachii, Squalomorphii)
【24h】

Node age estimations and the origin of angel sharks, Squatiniformes (Neoselachii, Squalomorphii)

机译：节点年龄估计和天使鲨，鱿鱼形（Neoselachii，Squalomorphii）的起源

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

The fossil record of angel sharks is reviewed with special focus on skeletal remains. A new family daggerPseudorhinidae is established for two species based on complete specimens from the Late Jurassic and a possible third species based on isolated teeth. This clade is a member of the stem lineage of Squatiniformes. Squatinidae represents the crown with a reliable fossil record extending back into the Aptian based on a partial skeleton displaying characteristic morphological traits of Squatina. We also present revised morphological descriptions of the skeletal remains of daggerSquatina baumbergensis (Campanian of Germany) and daggerSquatina sp. (Miocene of Japan). In this study, we used reliable skeletal remains and a modified approach to establish the origin and divergence of the Squatiniformes and the Squatinidae. Isolated teeth are considered to be unreliable because of the poor knowledge of squatiniform dental character traits and their evolution. We estimate a 'hard' minimum age constraint of 156.2 Ma and a 'soft' maximum age constraint of 181.74 Ma for the origin of the Squatiniformes. For the crown represented by the Squatinidae, we estimate a 'hard' minimum age constraint of 114 Ma and a 'soft' maximum age constraint of 157.59 Ma. These age constraints most likely designate the timing of the origin of identifiable squatiniform and squatinid characters as currently understood rather than the origin of the Squatiniformes or the divergence between the daggerPseudorhinidae and the Squatinidae. The lack of pre-Late Jurassic pseudorhinids and pre-Cretaceous squatinids probably represents an artefact because characteristic squatiniform tooth morphologies, which generally provide only a restricted set of diagnosable features, might not have yet been fully developed. Consequently, skeletal remains of neoselachians from the Early and Middle Jurassic are crucial for establishing reliable characters of stem-lineage representatives and to avoid misinterpretations resulting from transferring morphological traits of the crown to fossil groups with unresolved interrelationships, as well as sister-group relations.
机译：审查了天使鲨鱼的化石记录，特别侧重于骨骼遗骸。根据侏罗纪晚期的完整标本，为两个物种建立了一个新的匕首Pseudorhinidae，根据孤立的牙齿建立了一个新的匕首。该进化枝是鳞茎类的茎谱系的成员。 Squatinidae以可靠的化石记录代表了王冠，该记录基于显示出Squatina特征形态特征的部分骨骼而延伸回Aptian。我们还提出了匕首Squatina baumbergensis（德国的Campanian）和匕首Squatina sp的骨骼残留的修订的形态学描述。 （日本中新世）。在这项研究中，我们使用了可靠的骨骼遗骸和一种改良的方法来确定鱿鱼科和鱿鱼科的起源和分歧。孤立的牙齿被认为是不可靠的，因为他们对鳞状牙齿的性状特征及其演化缺乏了解。我们估计鳞形目的起源的“硬”最小年龄限制为156.2 Ma，“软”最大年龄限制为181.74 Ma。对于以鳞科代表的树冠，我们估计“硬”最小年龄限制为114 Ma，“软”最大年龄限制为157.59 Ma。这些年龄限制很可能指定了目前了解的可辨认的鳞状和鳞状字符起源的时间，而不是鳞状目的起源或匕首假鳞孔科和鳞状科之间的分歧。缺乏侏罗纪前的假蛇形动物和白垩纪前的蛇形鲨鱼可能代表了一种人工制品，因为通常仅提供有限的一组可诊断特征的典型的鳞齿状牙齿形态可能尚未得到充分发展。因此，早侏罗世和中侏罗世的新生龙骨的骨骼遗骸对于建立茎谱系代表的可靠特征，避免因将冠的形态特征转移给具有不可解决的相互关系的化石群以及姐妹群关系而造成的误解至关重要。

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