The oldest Archaeopteryx (Theropoda: Avialiae): a new specimen from the Kimmeridgian/Tithonian boundary of Schamhaupten, Bavaria.
The oldest Archaeopteryx (Theropoda: Avialiae): a new specimen from the Kimmeridgian/Tithonian boundary of Schamhaupten, Bavaria.
复制标题
最古老的考古学（Theropoda：Avialiae）：巴伐利亚Schamhaupten的Kimmeridgian/Tithonian边界的新标本。
作者：
Rauhut OWM;Foth C;Tischlinger H
到目前为止，标志性的原始鸟类始祖鸟主要是在德国南部巴伐利亚的阿尔特米尔塔尔组（早期提托尼亚）中发现的，其中一个标本是在上覆的门斯海姆组中发现的。一个新的标本（第12个骨骼标本）来自Schamhaupten（巴伐利亚）最早的Tithonian Painten Formation，是迄今为止该属最古老的代表。新的标本显示了几个有趣的解剖细节，包括存在一个与jugal接触的postorbital，存在一个单独的前额和冠状骨，以及opisthocoelous中颈椎。根据对新标本的观察，我们讨论了有关始祖鸟的几个问题，包括属的单系和诊断，胸骨的存在/缺失，胃的位置，以及在该属的形态测量学和牙齿形态的变化。基于对始祖鸟属的新诊断，柏林、艾希施泰特、索恩霍芬、慕尼黑、戴亭、瑟莫波利斯、第11和第12号标本可以高度肯定地被归为该属。根据整体相似性，马克斯伯格标本很可能也是始祖鸟，尽管没有一个诊断特征可以肯定地评估。第九个标本（“鸡翅”）可能是始祖鸟，但不能肯定地说是属。与其他副鸟相比，胸前肋远端增厚，表明该分类群中存在相当大的软骨胸骨。与非后耻骨兽脚类相反，后耻骨分类群，如始祖鸟和许多其他副鸟，胃篮后端保留在耻骨的一半长度，这可能反映了这些类群中腹部气囊扩大的死后塌陷。可以被称为始祖鸟的标本显示出很大的变化，无论是在肢体骨骼的形态测量学，以及在齿系。在后一方面，发现在牙齿数量，间距，方向和形态的变化，没有两个标本显示完全相同的模式。这种变化的意义尚不清楚，可能的解释是从高种内（可能是个体发育和/或性二态）变异的可能性，即已知标本代表一个“种群”的始祖鸟，可能是由于岛屿物种形成后，最初的属扩散到Solnhofen群岛。
The iconic primeval bird Archaeopteryx was so far mainly known from the Altmühltal Formation (early Tithonian) of Bavaria, southern Germany, with one specimen having been found in the overlying Mörnsheim Formation. A new specimen (the 12th skeletal specimen) from the earliest Tithonian Painten Formation of Schamhaupten (Bavaria) represents the so far oldest representative of the genus. The new specimen shows several interesting anatomical details, including the presence of a postorbital in contact with the jugal, the presence of a separate prefrontal and coronoid, and opisthocoelous mid-cervical vertebrae. Based on observations on the new specimen, we discuss several problematic issues concerning Archaeopteryx, including the monophyly and diagnosis of the genus, the absence/presence of the sternum, the position of the gastralia, and variation in morphometrics and dental morphology in that genus. Based on a new diagnosis for the genus Archaeopteryx, the Berlin, Eichstätt, Solnhofen, Munich, Daiting, Thermopolis, 11th, and 12th specimens can be referred to this genus with high certainty. The Maxberg specimen is very probably also an Archaeopteryx, based on overall similarity, although none of the diagnostic characters can be evaluated with certainty. The ninth specimen (‘chicken wing’) might be Archaeopteryx, but cannot be referred to the genus with any certainty. In comparison with other paravians, the presence of distally thickened anterior pectoral ribs indicates that a rather large cartilagenous sternum was present in this taxon. In contrast to non-opisthopubic theropods, opisthopubic taxa, such as Archaeopteryx and many other paravians, have the posterior end of the gastral basket preserved at about half-length of the pubis, which might reflect the post-mortem collapse of enlarged abdominal air sacs in these taxa. Specimens that can be referred to Archaeopteryx show a high amount of variation, both in the morphometrics of the limb bones as well as in the dentition. In respect to the latter aspect, variation is found in tooth number, spacing, orientation, and morphology, with no two specimens showing the exact same pattern. The significance of this variation is unclear, and possible explanations reach from high intraspecific (and possibly ontogenetic and/or sexual dimorphic) variation to the possibility that the known specimens represent a ‘species flock’ of Archaeopteryx, possibly due to island speciation after the initial dispersal of the genus into the Solnhofen Archipelago.
影响因子：
64.8
作者：
Alonso, PD;Milner, AC;Rowe, TB
通讯作者：
Rowe, TB
影响因子：
64.8
作者：
Abzhanov, Arhat;Kuo, Winston P.;Tabin, Clifford J.
通讯作者：
Tabin, Clifford J.