One of the diagnostic characters of dicraeosaurid sauropods is a reduction of pneumatization of dorsal and caudal vertebrae relative to their Flagellicaudata sister taxon, Diplodocidae. Here, we analyse pneumatic structures in the dicraeosaurid sauropod Pilmatueia faundezi, compare them to those of diplodocoids and report the first record of camerate chambers in a dicraeosaurid. The pneumatic structures are in a posterior cervical centrum (MLL‐Pv‐002) and consist of lateral pneumatic fossae on the centrum that communicate internally with large camerae. By contrast, Pilmatueia's dorsal and caudal vertebrae (MLL‐Pv‐005‐016) lack pneumatic fossae on the centra, which is consistent with the previously reported reduced pneumaticity in dicraeosaurids. Nevertheless, the base of the neural arch and possibly the base of the bifid neural spines of a posterior dorsal vertebra (MLL‐Pv‐005) show pneumatic internal chambers. The pneumatic features of the Pilmatueia cervical centrum and dorsal neural arch we describe indicate that the degree of pneumatization is variable within dicraeosaurids.

中文翻译：

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阿根廷西北巴塔哥尼亚早白垩世蜥脚类恐龙Pilmatueia faundezi的椎骨气动结构

cra龙类蜥脚类动物的诊断特征之一是相对于鞭毛龙的姊妹分类群双翅目科减少了背侧和尾椎的气化。在这里，我们分析了龙骨蜥脚类龙虾Pilmatueia faundezi中的气动结构，将其与双齿类动物的气动结构进行比较，并报告了龙骨蜥脚类摄像室的首次记录。气动结构位于子宫颈后中央（MLL-Pv-002）中，由在中央的侧向气动窝组成，内部与大型摄像机通信。相比之下，毛细血管炎的背侧和尾椎（MLL-Pv-005-016）在中央缺少气动小窝，这与先前报道的龙骨龙的气动性降低相一致。尽管如此，后背椎骨（MLL-Pv-005）的神经弓基部和可能的双裂神经棘基部仍显示有气动内腔。我们描述的毛细支气管颈椎中枢和背神经弓的气动特征表明，在di龙内，气化程度是可变的。