著者

TOMO TAKANO MASATO NAKATSUKASA MARTA PINA YUTAKA KUNIMATSU YOSHIHIKO NAKANO NAOKI MORIMOTO NAOMICHI OGIHARA HIDEMI ISHIDA

出版者

The Anthropological Society of Nippon

雑誌

Anthropological Science (ISSN:09187960)

巻号頁・発行日

pp.200116, (Released:2020-03-17)

被引用文献数

5

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This article reports eight new humeral, ulnar, and radial fragments of Nacholapithecus kerioi collected from Nachola, Kenya during the 1998/1999 field seasons. The study refines the description of its forelimb bones, which was mostly based on a single partial skeleton. The most distinctive feature of the distal humerus is a large, globular, medially tilted capitulum. The groove between the capitulum and the zona conoidea is quite deep. The medial part of the humeral trochlea is also diagnostic in showing a less salient medial border. The medial epicondyle is moderately long and more posteriorly reflected than was previously presumed. The coronoid process of the ulna is quite wide. Its medial portion is distinctly concave. The ulnar shaft is anteroposteriorly deep in its proximal half, slender, straight in frontal view, and weakly anteriorly bowing. The elbow of Nacholapithecus exhibits a primitive functional pattern as a hominoid, including lack of universal stability of the humeroulnar joint through full extension and flexion, restriction of hyperextension of the elbow, and relatively anteroposteriorly oriented loading at the proximal ulna. On the other hand, it is derived in terms of enhanced rotational mobility and stability of the radius, incipiently increased stability at the humeroulnar joint, and more frequent maximum extension of the elbow compared to proconsulids. This mosaic morphology is different from both early Miocene proconsulids and later suspensory or orthograde European fossil apes. Although Nacholapithecus was neither suspensory nor orthograde, its forelimbs may have played a greater role for body support or balance maintenance, more frequently reaching to and exploiting overhead supports than in early Miocene proconsulids.

著者

TOMO TAKANO MASATO NAKATSUKASA YUTAKA KUNIMATSU YOSHIHIKO NAKANO NAOMICHI OGIHARA HIDEMI ISHIDA

出版者

The Anthropological Society of Nippon

雑誌

Anthropological Science (ISSN:09187960)

巻号頁・発行日

vol.126, no.3, pp.135-149, 2018 (Released:2018-12-21)

参考文献数

59

被引用文献数

10

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This paper provides a thorough description of humeral, ulnar, and radial specimens of the Nacholapithecus holotype (KNM-BG 35250). A spool-shaped humeral trochlea (and keeled sigmoid notch of the ulna) is a hallmark of elbow joint evolution in hominoids. In lacking this feature, the elbow of Nacholapithecus is comparatively primitive, resembling that of proconsulids. However, the humeroulnar joint in Nacholapithecus is specialized for higher stability than that in proconsulids. The humeroradial joint (humeral capitulum) resembles that of extant apes and Sivapithecus. This condition may represent an intermediate stage leading to the fully modern elbow in extant apes. If this is the case, specialization of the humeroradial joint preceded that of the humeroulnar joint. Nacholapithecus elbow joint morphology suggests more enhanced forearm rotation compared to proconsulids. This observation accords with the forelimb-dominated positional behavior of Nacholapithecus relative to proconsulids, which has been proposed on the grounds of limb proportions and the morphology of the phalanges, shoulder girdle, and vertebrae.

著者

YUTAKA KUNIMATSU YOSHIHIRO SAWADA TETSUYA SAKAI MOTOTAKA SANEYOSHI HIDEO NAKAYA AYUMI YAMAMOTO MASATO NAKATSUKASA

出版者

The Anthropological Society of Nippon

雑誌

Anthropological Science (ISSN:09187960)

巻号頁・発行日

vol.125, no.2, pp.45-51, 2017 (Released:2017-09-21)

参考文献数

58

被引用文献数

2

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The African primate fossil record is very poor between the mid-Middle and mid-Late Miocene. Nakali (~10–9.8 Ma) is one of the rare African localities that have yielded primate fossils from this period, including a new genus of great ape, Nakalipithecus nakayamai, and another large-bodied hominoid species. The Nakali primate fauna also includes small-bodied ‘apes’ and Old World monkeys (mostly colobines). In this article, we describe a new specimen of a small-bodied ‘ape’ discovered from Nakali, which is assigned to nyanzapithecines. Nyanzapithecines are characterized by their derived dental morphology, and the previously known nyanzapithecines range in chronological age between the Late Oligocene and early Middle Miocene (~25–13.7 Ma). The new nyanzapithecine specimen from Nakali is therefore the latest occurrence of this group in the African fossil record, extending its chronological range by almost 4 million years younger.

著者

YUTAKA KUNIMATSU YOSHIHIRO SAWADA TETSUYA SAKAI MOTOTAKA SANEYOSHI HIDEO NAKAYA AYUMI YAMAMOTO MASATO NAKATSUKASA

出版者

The Anthropological Society of Nippon

雑誌

Anthropological Science (ISSN:09187960)

巻号頁・発行日

pp.170126, (Released:2017-04-29)

被引用文献数

2

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The African primate fossil record is very poor between the mid-Middle and mid-Late Miocene. Nakali (~10–9.8 Ma) is one of the rare African localities that have yielded primate fossils from this period, including a new genus of great ape, Nakalipithecus nakayamai, and another large-bodied hominoid species. The Nakali primate fauna also includes small-bodied ‘apes’ and Old World monkeys (mostly colobines). In this article, we describe a new specimen of a small-bodied ‘ape’ discovered from Nakali, which is assigned to nyanzapithecines. Nyanzapithecines are characterized by their derived dental morphology, and the previously known nyanzapithecines range in chronological age between the Late Oligocene and early Middle Miocene (~25–13.7 Ma). The new nyanzapithecine specimen from Nakali is therefore the latest occurrence of this group in the African fossil record, extending its chronological range by almost 4 million years younger.

著者

YUTAKA KUNIMATSU HIROSHI TSUJIKAWA MASATO NAKATSUKASA DAISUKE SHIMIZU NAOMICHI OGIHARA YASUHIRO KIKUCHI YOSHIHIKO NAKANO TOMO TAKANO NAOKI MORIMOTO HIDEMI ISHIDA

出版者

The Anthropological Society of Nippon

雑誌

Anthropological Science (ISSN:09187960)

巻号頁・発行日

vol.125, no.2, pp.59-65, 2017 (Released:2017-09-21)

参考文献数

52

被引用文献数

2

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We here describe a prosimian specimen discovered from the early Middle Miocene (~15 Ma) of Nachola, northern Kenya. It is a right maxilla that preserves P4–M3, and is assigned to a new species of the Miocene lorisid genus Mioeuoticus. Previously, Mioeuoticus was known from the Early Miocene of East Africa. The Nachola specimen is therefore the first discovery of this genus from the Middle Miocene. The presence of a new lorisid species in the Nachola fauna indicates a forested paleoenvironment for this locality, consistent with previously known evidence including the abundance of large-bodied hominoid fossils (Nacholapithecus kerioi), the dominance of browsers among the herbivore fauna, and the presence of plenty of petrified wood.

著者

国松 豊 YUTAKA KUNIMATSU 京都府立大学農学部畜産学研究室 Laboratory of animal Sciene Faculty of Agriculture Kyoto Prefectural University

出版者

京都府立大学学術報告委員会

雑誌

京都府立大學學術報告. 農學 = The scientific reports of Kyoto Prefectural University. Agriculture (ISSN:00757373)

巻号頁・発行日

vol.35, pp.36-40, 1983-11-15

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専業養鶏場における破卵率を調査し, 次いで正常卵と破卵の卵殻形質を比較検討した。第1試験では城陽市の専業養鶏場においてケージ上での破卵率をゴトー360(G鶏)とシェーバー・スタークロス288(S鶏)の2鶏種について昭和56年7月24日より11月13日までの間で11回調査した。その結果, 平均破卵率はG鶏は3.9%, S鶏は5.3%であった。また, 鶏齢と破卵率の関係を調査した結果, 9か月齢(若齢鶏)のG鶏の破卵率は1.8%, S鶏は1.5%であった。また, 21か月齢(老齢)のG鶏の破卵率は8.2%, S鶏は6.4%であり, 両鶏種とも老齢鶏の方が有意の高い破卵率であった。第2試験では, ハイセックス鶏とハーバート・コメット鶏の2鶏種について, 破卵の破損部位と卵殻の厚さ調査した結果, 鶏卵の鋭端部の破損がもっとも多く, 卵殻の厚さは正常卵に比較して破卵の方がすべての部位で有意に薄かった。第3試験では, ハイセックス鶏とハーバード・コメット鶏の2鶏種について, 正常卵と破卵の卵重, 卵殻重, 卵殻重比, 卵殻の厚さおよびSWU SAを比較した結果, 両鶏種とも破卵の方が卵殻重, 卵殻重比, 卵殻の厚さおよびSWUSAといづれも有意に低い値であった。The present study was to examin the percentage of cracked eggs as affected by the strain and age of hen in the local poultry farm and the difference of the egg shell qualities between normal and cracked eggs. Between the 2 strains of han used, Goto 360 (3.9%) and shaver star cross 288 (5.3%), there was no significant difference in the percentage of cracked eggs. However, significantly higher percentage of cracked eggs in aged hens (21 months old; 6.3-8.2%) than in young ones (9 months old; 1.5-1.8%). In another series of experiment with two strains of hen (Hisex and Hubbard Comet), the most (43-50%) of cracked eggs were damaged at the small end of the eggs. The egg shell was significantly thiner in cracked eggs than in normal ones. Finally, in the experiment with Hisex and Hubbard Comet, it was found that shell weight, shell percent, shell thickness and shell weight per unit shell surface area were all significantly greater in normal eggs compared with cracked ones, indicating inferior qualities of the egg shell in the latter.