- 著者
- Endo Hideki Niizawa Nobuharu Komiya Teruyuki Kawada Shinichiro Kimura Junpei Itou Takuya Koie Hiroshi Sakai Takeo
- 出版者
- Zoological Society of Japan
- 雑誌
- Zoological Science (ISSN:02890003)
- 巻号頁・発行日
- vol.24, no.10, pp.1005-1011, 2007-10
- 被引用文献数
- 17
The gross anatomy of the mastication system of the giant anteater (Myrmecophaga tridactyla) was examined by means of three-dimensional image analysis. The anteater rotates the mandibles medially and laterally to control its tongue when it is elongated and to house it when it is relaxed. Three-dimensional CT image analysis demonstrated that the shape and size of the oral cavity changes drastically when the mandibles are rotated. The oral cavity expands bilaterally when the dorsal part of the mandibles bend medially. Macroscopic observations and muscle-weight data supported the observation that the superficial temporal and medial pterygoid muscles act as the main medial and lateral rotators of the mandible, respectively. The low height of the mandibular ramus and the incomplete zygomatic arch in this species represent adaptations for the rotational movement of the mandibles, since they both contribute to the medially oriented transmission of force from the temporal muscles and to preventing collision between the mandibles and the cranium during the rotational movement.
- 著者
- Endo Hideki Niizawa Nobuharu Komiya Teruyuki Kawada Shinichiro Kimura Junpei Itou Takuya Koie Hiroshi Sakai Takeo
- 出版者
- Zoological Society of Japan
- 雑誌
- Zoological science (ISSN:02890003)
- 巻号頁・発行日
- vol.24, no.10, pp.1005-1011, 2007-10
- 被引用文献数
- 2 17
The gross anatomy of the mastication system of the giant anteater (Myrmecophaga tridactyla) was examined by means of three-dimensional image analysis. The anteater rotates the mandibles medially and laterally to control its tongue when it is elongated and to house it when it is relaxed. Three-dimensional CT image analysis demonstrated that the shape and size of the oral cavity changes drastically when the mandibles are rotated. The oral cavity expands bilaterally when the dorsal part of the mandibles bend medially. Macroscopic observations and muscle-weight data supported the observation that the superficial temporal and medial pterygoid muscles act as the main medial and lateral rotators of the mandible, respectively. The low height of the mandibular ramus and the incomplete zygomatic arch in this species represent adaptations for the rotational movement of the mandibles, since they both contribute to the medially oriented transmission of force from the temporal muscles and to preventing collision between the mandibles and the cranium during the rotational movement.
- 著者
- Sasaki Motoki Endo Hideki Yamamoto Masako ARISHIMA Kazuyoshi HAYASHI Yoshihiro
- 出版者
- 日本哺乳類学会
- 雑誌
- Mammal study = The Continuation of the Journal of the Mammalogical Society of Japan (ISSN:13434152)
- 巻号頁・発行日
- vol.25, no.1, pp.27-34, 2000-06-01
- 被引用文献数
- 3 7
The musculature and functional anatomy of the head and skull of a tiger <i>Panthera tigris</i> were, examined and compared with those of various other felid species. The <i>Musculus masseter</i> is divided into three layers. The superficial layer of which is well-developed and further sub-divided into lateral and medial components. The ventro-caudal fleshy portion of the lateral component originates behind the last upper molar, where it is attached by a strong tendon to the tubercle <i>tuber maxillae</i>. The medial component, which runs dorso-ventrally, has a particularly well-developed fleshy portion. The present anatomical study suggests that in the tiger, large masseteric forces are produced in both ventro-rostral and ventro-dorsal directions. In the tiger, a process is present on the tubercle of the maxilla from which the strong tendon originates. This process is also apparent in the leopard <i>Panthera pardus</i>, the jaguar <i>P. onca</i> and the puma <i>Felis concolor</i>. It is not found, however, in either the domestic cat <i>F. catus</i> or the Iriomote wild cat <i>F. iriomotensis</i>. Comparisons between the skulls of various species of felidae indicate that whereas the puma, the leopard and the jaguar each possess the strong tendon, which bundles the ventro-caudal fleshy portion of the lateral component, the domestic cat and the Iriomote wild cat only possess weak tendons attaching to this component.