College of Life Sciences, Capital Normal University, Beijing, China.
PLoS One. 2012;7(11):e48842. doi: 10.1371/journal.pone.0048842. Epub 2012 Nov 9.
Old World vultures are likely polyphyletic, representing two subfamilies, the Aegypiinae and Gypaetinae, and some genera of the latter may be of independent origin. Evidence concerning the origin, as well as the timing of the divergence of each subfamily and even genera of the Gypaetinae has been elusive.
METHODOLOGY/PRINCIPAL FINDINGS: Compared with the Old World, the New World has an unexpectedly diverse and rich fossil component of Old World vultures. Here we describe a new accipitriform bird, Anchigyps voorhiesi gen. et sp. nov., from the Ash Hollow Formation (Upper Clarendonian, Late Miocene) of Nebraska. It represents a form close in morphology to the Old World vultures. Characteristics of its wing bones suggest it was less specialized for soaring than modern vultures. It was likely an opportunistic predator or scavenger having a grasping foot and a mandible morphologically similar to modern carrion-feeding birds.
CONCLUSIONS/SIGNIFICANCE: The new fossil reported here is intermediate in morphology between the bulk of accipitrids and the Old World gypaetine vultures, representing a basal lineage of Accipitridae trending towards the vulturine habit, and of its Late Miocene age suggests the divergence of true gypaetine vultures, may have occurred during or slightly before the Miocene.
旧大陆秃鹫可能是多系的，代表两个亚科，即 Aegypiinae 和 Gypaetinae，而后者的一些属可能具有独立的起源。关于起源以及每个亚科甚至 Gypaetinae 属的分化时间的证据一直难以捉摸。
方法/主要发现：与旧大陆相比，新大陆具有意想不到的多样化和丰富的旧大陆秃鹫化石成分。在这里，我们描述了一种来自内布拉斯加州 Ash Hollow 组（上 Clarendonian，中新世晚期）的新型鹰形目鸟类，Anchigyps voorhiesi gen. et sp. nov.。它代表了一种与旧大陆秃鹫形态相近的形式。其翼骨特征表明它不像现代秃鹫那样专门用于翱翔。它可能是一种机会主义的捕食者或食腐动物，具有抓握的脚和在形态上类似于现代腐肉鸟类的下颌。
结论/意义：这里报道的新化石在形态上介于大多数鹰形目和旧大陆的拟兀鹫秃鹫之间，代表了 Accipitridae 向兀鹫习性的基础谱系，并且它的中新世年龄表明真正的兀鹫秃鹫的分化可能发生在中新世期间或稍早。
