Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.
Área de Paleontología, Fundación Félix de Azara, Universidad Maimónides, Hidalgo 775, C1405BCK, Buenos Aires, Argentina.
Sci Rep. 2019 Feb 4;9(1):1392. doi: 10.1038/s41598-018-37943-3.
Dicraeosaurids are a group of sauropod dinosaurs characterized by a distinctive vertebral column with paired, long, neural spines, present in an extreme fashion in the South American form Amargasaurus cazaui. This distinctive morphology has been interpreted as a support structure for a thermoregulatory sail, a padded crest for display, a dorsal hump acting as fat reservoir, and even as inner cores for dorsal horns. Other inferred functions (if any) of this structure were related to sexual display and/or defense strategies. Here we describe a new dicraeosaurid sauropod, Bajadasaurus pronuspinax gen. et sp. nov., from Patagonia which preserves the most complete skull of the group and has extremely elongate bifid cervical neural spines that point permanently forward, irrespective of the neck position. Although much shorter versions of this neural spine configuration were already recorded for other dicraeosaurid taxa, the long, anteriorly bent spines of this new dinosaur support the hypothesis that these elongate spines of dicraeosaurid sauropods served as passive defense structures.
巨龙形类恐龙是蜥脚形亚目恐龙的一个支系，其特征是具有一对独特的、长而分叉的神经棘，这一特征在南美洲的阿马加龙属形式中表现得尤为极端。这种独特的形态被解释为用于支持热调节帆的结构，用于展示的有衬垫的嵴，作为脂肪储存库的背部驼峰，甚至作为背部角的内部核心。该结构的其他推断功能（如果有的话）与性展示和/或防御策略有关。本文描述了一种来自巴塔哥尼亚的新巨龙形类蜥脚类恐龙，弯龙属pronuspinax 种，它保存了该类群最完整的头骨，并且具有极其细长的二分叉颈椎神经棘，这些神经棘永久性地向前指向，无论颈部位置如何。尽管其他巨龙形类恐龙已经记录了这种神经棘配置的更短版本，但这种新恐龙的长、向前弯曲的神经棘支持了这样一种假说，即巨龙形类蜥脚类恐龙的这些长神经棘起到了被动防御结构的作用。
