Grupo de Biología Evolutiva, UNED, Paseo Senda del Rey 9, 28040, Madrid, Spain.
Unidad de Paleontología, Universidad Autónoma de Madrid, C/Darwin 2 28049, Madrid, Spain.
Sci Rep. 2017 Feb 7;7:42035. doi: 10.1038/srep42035.
Dermal armor is one of the most intriguing features of some titanosaurs, the only sauropod dinosaurs that bore osteoderms. Some studies have revealed cavities of varying sizes inside some titanosaur osteoderms, interpreted as the result of bone remodeling for mineral mobilization. Several hypotheses have been proposed to explain the need for mineral mobilization in titanosaurs. However, rejecting those hypotheses was difficult with hitherto available evidence. The Upper Cretaceous site of Lo Hueco (Cuenca; Spain) has yielded one of the largest titanosaur osteoderm sets available. Observation of pre-existing breakages in the fossils and CT-scanning have revealed a predominant internal channel network for bulb and root osteoderms: most had a very compact spongy bone core, perfused by large longitudinal branching neurovascular canals. Only few osteoderms from the same bed, which was deposited in a single and short event, had areas with low-density spongy bone. This void-like low-density bone is always associated with internal channels. It is also present in osteoderms of different sizes. This scenario is best explained when considering that Lo Hueco titanosaurs might have used their osteoderms as a source of calcium that was mobilized during oogenesis, although other hypotheses cannot be completely ruled out.
皮肤盔甲是一些巨龙形类恐龙（唯一长有骨板的蜥脚类恐龙）最引人注目的特征之一。一些研究揭示了一些巨龙形类恐龙骨板内存在大小不一的腔隙，被解释为矿物质动员的骨重塑的结果。已经提出了几种假说来解释巨龙形类恐龙需要矿物质动员的原因。然而，由于迄今为止的证据有限，很难否定这些假说。上白垩统的 Lo Hueco 遗址（西班牙昆卡）出土了一批可供研究的最大的巨龙形类恐龙骨板之一。对化石中现有破裂的观察和 CT 扫描揭示了一个主要的内部通道网络，用于鳞和根骨板：大多数都有一个非常致密的海绵状骨芯，由大的纵向分支神经血管通道灌注。只有同一层中少数骨板的海绵骨密度较低，该层是在单一且短暂的事件中沉积的。这种类似空洞的低密度骨总是与内部通道相关。在不同大小的骨板中也存在这种情况。当考虑到 Lo Hueco 巨龙形类恐龙可能将它们的骨板用作在卵母细胞发生过程中动员钙的来源时，这种情况是最容易解释的，尽管其他假说也不能完全排除。
