Non-destructive analysis of in situ ammonoid jaws by synchrotron radiation X-ray micro-computed tomography
Non-destructive analysis of in situ ammonoid jaws by synchrotron radiation X-ray micro-computed tomography
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DOI：
10.26879/697
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发表时间：
2016-11
影响因子：
2
通讯作者：
Yusuke Takeda;K. Tanabe;Takenori Sasaki;K. Uesugi;M. Hoshino
中科院分区：
文献类型：
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作者：
Yusuke Takeda;K. Tanabe;Takenori Sasaki;K. Uesugi;M. Hoshino
我们首次引入高分辨率同步辐射x射线断层扫描技术，对保存在晚白垩世Phyllopachyceras ezoensis体内的颌骨进行无损三维重建。利用线性吸收系数对x射线图像进行分析，发现上颌主要由由碳酸盐磷灰石组成的内外片组成，其最初可能是一种几丁质-蛋白质复合物，边缘呈角状的厚钙质物质。形态学特征表明该物种的颚器为舌颚类。这些标本的下颚器官的三维结构与其他菊石相似，除了在上下颚发育了一层厚厚的钙化沉积物，这可以被认为支持了该物种的捕食-食腐食性。该物种的下颌特征似乎受到系统发育和功能形态因素的限制。Yusuke武田。东京大学地球与行星科学系，日本东京文京区本乡7-3-1，日本东京113-0033ytakeda@um.u-tokyo.ac.jp田边和成。东京大学地球与行星科学系，日本东京文京区本乡7-3-1，日本东京113-0033tanabe@um.u-tokyo.ac.jp佐佐木武则。东京大学博物馆，东京文京区本古7-3-1，日本东京1130033。sasaki@um.u-tokyo.ac.jp上杉健太郎。日本同步辐射研究所（JASRI），日本兵库县Sayo-cho口户1-1-1，日本679-5198。ueken@spring8.or.jp星野正人。日本同步辐射研究所（JASRI），日本兵库县Sayo-cho口户1-1-1，日本679-5198。hoshino@spring8.or.jp
We introduce high-resolution synchrotron radiation X-ray tomography for nondestructive, three-dimensional reconstruction of the jaw apparatus preserved within the body chamber of the Late Cretaceous phylloceratid ammonoid, Phyllopachyceras ezoensis, for the first time. Analysis of the X-ray images using linear absorption coefficient estimation reveals that the upper jaw consisted mainly of inner and outer lamellae composed of carbonate apatite, which originally might have been a chitin-protein complex, with angulated rims of thick calcareous material. The morphological features indicate that the jaw apparatus of this species is the rhynchaptychus-type. The threedimensional architecture of the jaw apparatus of these specimens is similar to that of other ammonoids, except for the development of a thick calcified deposit in both upper and lower jaws, which can be considered to support the predatory-scavenging feeding habits of the species. The jaw features of this species appear to have been constrained by both phylogenetic and functional morphological factors. Yusuke Takeda. Department of Earth and Planetary Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan. ytakeda@um.u-tokyo.ac.jp Kazushige Tanabe. Department of Earth and Planetary Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan. tanabe@um.u-tokyo.ac.jp Takenori Sasaki. The University Museum, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 1130033, Japan. sasaki@um.u-tokyo.ac.jp Kentaro Uesugi. Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1, Kouto, Sayo-cho, Sayogun, Hyogo 679-5198 Japan. ueken@spring8.or.jp Masato Hoshino. Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1, Kouto, Sayo-cho, Sayogun, Hyogo 679-5198 Japan. hoshino@spring8.or.jp