A new carinate bird from the Late Cretaceous of Patagonia (Argentina).
A new carinate bird from the Late Cretaceous of Patagonia (Argentina).
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DOI：
10.1206/0003-0082(2001)323
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发表时间：
2001-02-27
影响因子：
1.5
通讯作者：
Chiappe, Luis M.
中科院分区：
文献类型：
--
作者：
Clarke, Julia A.;Chiappe, Luis M.
一种新的鸟类从晚白垩世巴塔哥尼亚（阿根廷），已知相关的翅膀元素，描述和其系统发育的位置进行了评估。化石类群以及现存鸟类的代表物种的血统被认为是基础内冠分支的72个字符主要从胸肢的分支分析。根据系统发育分析和形态学鉴定结果，我们将其命名为一个新分类群-Limenavis patagonica。Limenavis patagonica被认为比反鸟目更接近冠支，因为它有三个明确的突触：肱骨背侧最远端的窝（有时有两个可区分的子部分）;掌骨II和III的远端融合;掌骨I上的伸肌突。它比鱼鸟更靠近冠部分支，因此，由于两个进一步的联会形象，明确地作为隆突（参见术语的方法）：尺骨的背侧trochiar表面与尺骨干的突然截短接触和尺骨远端肌腱沟附近的结节丢失。最后，根据以下三种自体象诊断出巴塔哥尼亚Limenavis：肱骨尺侧隆起的尺侧部附着在尺骨近端，形成一个坑状窝;豌豆突的位置，其近端表面与第一掌骨近端表面大致相同;尺骨腹侧副韧带的瘢痕向近远侧延长并向下延伸至肱压迹的尾侧边缘。Limenavis patagonica位于鸟类冠状分支之外。最短的树与新的分类单元的一部分，树冠分支是五个步骤比最简约的拓扑结构。
A new bird from the Late Cretaceous of Patagonia (Argentina), known from associated wing elements, is described and its phylogenetic position evaluated. Fossil taxa as well as representatives of species of extant birds sampled from lineages considered to be basal within the crown clade were included in a cladistic analysis of 72 characters primarily from the thoracic limb. Based on the results of the phylogenetic analysis and identification of autapomorphies in the specimen, we name a new taxon Limenavis patagonica. Limenavis patagonica is identified as closer to the crown clade than Enantiornithes by the presence of three unambiguous synapomorphies: a fossa (sometimes with two distinguishable subparts) on the dorsal, distalmost extremity of the humerus; distal fusion of metacarpals II and III; and an extensor process on metacarpal I. It is placed closer to the crown clade than Ichthyornis, and, thus, unambiguously as a carinate (see Methods for terminology), by two further synapomorphies: the abruptly truncate contact of the dorsal trochlear surface of the ulna with the ulnar shaft and the loss of a tubercle adjacent to the tendinal groove on the distal ulna. Finally, Limenavis patagonica is diagnosed by three autapomorphies: the attachment of the pars ulnaris of the trochlea humeroulnaris on the proximal ulna developed as a pit-shaped fossa; the location of the pisiform process with its proximal surface at approximately the same level as the proximal surface of metacarpal I; and a scar of the ligamentum collaterale ventrale of the ulna proximodistally elongate and extending down the caudal margin of the brachial impression. Limenavis patagonica is placed just outside the avian crown clade. The shortest tree with the new taxon as part of the crown clade is five steps longer than the most parsimonious topology.