COLLABORATIVE RESEARCH: Soft Tissue and Membrane Preservation in Permian Cephalopods

我们计划调查北美二叠纪沉积物中头足类软体动物的内部特征。特别是，我们正在研究内华达州巴克山二叠纪头足类动物中被早期成岩磷酸盐矿化保存下来的虹吸索和膜的软组织。这项研究代表了我们最初在该地区的三个氨状标本中发现的保存膜的后续研究。我们计划扩大这一发现，我们的主要目标是检查巴克山头足类动物群，以寻找保存下来的膜和软组织。该动物群包括原螺目、角螺目和鹦鹉螺目，生活在俄亥俄大学和博伊西州立大学。我们将使用酸化技术制备这些头足类动物，然后用扫描电子显微镜检查标本。古生代头足类软组织和软组织膜的研究一直是一个遥不可及的研究目标。我们提出了两个假设：1)这些头足类动物的结构确实是软组织残骸，现在已经磷化，保存了它们原始显微解剖的细节；2)这些结构与现代头足类动物的结构是同源的，并揭示了系统发育和功能形态的信息。这项研究将有助于更好地了解这些古老而灭绝的动物是如何在其环境中生活和发挥作用的。这样，这些发现将有助于我们对头足类化石的古生物学基础知识。

We plan to investigate the internal features of cephalopod molluscs from Permian deposits in North America. In particular, we are studying the remains of soft tissues of siphuncular cords and membranes that have been preserved by early diagenetic phosphate mineralization in Permian cephalopods from Buck Mountain, Nevada. This research represents a follow-up study of our initial discovery of preserved membranes in three ammonoid specimens from this locality. We plan to expand this discovery with our primary objective the examination of the Buck Mountain cephalopod fauna for preserved membranes and soft tissues. This fauna includes prolecanitids, goniatitids, and nautiloids and is housed in Ohio University and Boise State University. We will prepare these cephalopods using acidification techniques and then examine the specimens with scanning electron microscopy. The study of the remains of soft tissues and membranes in Paleozoic cephalopods has previously been an unobtainable research goal. We pose two hypotheses: 1) the structures in these cephalopods are, indeed, soft tissue remains, now phosphatized, that preserve the details of their original microanatomy and 2) that these structures are homologous with those of modern cephalopods and reveal information about phylogeny and functional morphology. This study will lead to a better understanding of how these ancient and extinct animals lived and functioned in their environment. In this way, these discoveries will contribute to our fundamental knowledge of the paleobiology of fossil cephalopods.