The Appendicular Anatomy of the Elegant Crested Tinamou (Eudromia Elegans) 3
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Bull. Kitakyushu Mus. Nat. Hist. Hum.The Appendicular Hist., Ser. A, 12Anatomy: 1–48, ofMarch the Elegant 31, 2014 Crested Tinamou (Eudromia elegans) 1 The Appendicular Anatomy of the Elegant Crested Tinamou 北九州市立自然史・歴史博物館研究報告A類(自然史)投稿要領 (Eudromia elegans) 1 2 3 4 UZUKI HIBA AN UREN HASHI 1. 分野:自然史に関する原著論文,短報等(和文または欧文)でつぎのうち一つ以上にあたるもの. Daisuke S , Kentaro C , Collin S. V B & Tomoyuki O 1 ⑴ 北九州域の自然史に関するもの. Department of Anatomy, Sapporo Medical University, School of Medicine, Sapporo 060-8556, Japan 2 ⑵ 当館の収集活動に関するもの(例:新種記載に際して,ホロタイプまたはパラタイプ・トポタイ Department of Ecology and Evolutionary Biology, University of Toronto, Toronto M5S 3B2, Canada 3 プ等の標本が当館に収蔵される場合). Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, United Kingdom. 4 ⑶ 当館の行う調査研究に関係するもの. Kitakyushu Museum of Natural History & Human History, Kitakyushu 805-0071, Japan ⑷ 既に当館に収蔵されている標本に関するもの. (Received December 28, 2012; accepted February 4, 2014) ⑸ 当館学芸員の研究活動に関係するもの. ⑹ 編集委員会が適当と認めるもの. ABSTRACT — Tinamids are small cursorial birds with limited flight ability. They are phylogenetically nested within a clade composed mostly of large, flightless birds (ratites). Their ability to fly and the evolution of flightlessness in the clade are currently not well understood, and this is largely due to a paucity of literature on the 2. 審査:投稿原稿は,編集委員会ならびに委託された査読者による審査の後採否が決定される.修正 osteological and muscular anatomy of these birds. の必要のあるとされた原稿は,査読者の意見と共に返送されるので,著者は必要な訂正を行った後, Two Eudromia elegans (Palaeognathae: Tinamidae) were dissected and four skeletons were examined. The 速やかに再提出する.体裁については編集委員会に一任される. skeletons of Eudromia are characterized by a thin sternum, short and stout humeri, and developed lower limbs. Eudromia maintains some ancestral characters in the postcranial skeleton, such as elongated lateral trabeculae of the sternum, an absent rostral external spine of the sternum, and lack of fusion between the distal ilium and 3. 北九州市立自然史・歴史博物館研究報告A類(自然史)に掲載された論文の著作権(著作財産権, ischium. The lost of the hallux suggests cursorial adaptation occured not only in Strutioformes (Struthio has only Copyright)は,北九州市立自然史・歴史博物館に帰属するものとする. two digits) but also even in tinamids. Accordingly, the muscles inserting on the hallux are lost or shifted to other digits. However, the body plan of Eudromia is quite similar to other modern volant birds, like Gallus. Our specimens showed differences in musclular morphology from previous descriptions of tinamou anatomy, 4. 投稿を希望される方は,あらかじめ下記にご連絡下さい. particularly, the absence of M. iliofemoralis internus and the femoral head of M. tibialis cranialis. We also compared Eudromia with other ratites, such as Struthio, Rhea, Apteryx, and Dromaius. In the shoulder girdle, Eudromia has a large M. pectoralis thoracica and M. supracoracoideus, which are used for the downstroke and upstroke, 連絡先:北九州市立自然史・歴史博物館 respectively, but these muscles do not have such antagonistic actions in other ratites due to differing origins and 〒 805-0071 insertions. The morphological changes in the pelvic girdle are minor compared with those in shoulder and forelimb 北九州市八幡東区東田二丁目4番1号 regions. Ratite have enlarged Mm. femorotibiales, and M. iliotorochantericus medius and M. ischiofemoralis are diminished in size, except in . has a thin M. caudofemoralis pars pelvica, while other ratites have 電話 (0 93)681-1011 Apteryx Eudromia lost M. caudofemoralis pars caudalis (in Dromaius and Rhea) or it is considerably diminished (in Struthio). The FAX (093)661-7503 differences between Eudromia and other ratites we find are attributed to the retention of flight ability in Eudromia. KEY WORDS: Tinamou, Osteology, Myology, Comparative anatomy INTRODUCTION to all other palaeognaths (e.g., CRACRAFT, 1974; CASPERS et al., 1994; CRACRAFT & CLARKE, 2001) and others recovering Tinamous (Palaeognathae: Tinamidae) are a monophyletic the ostrich (Struthio) as the outgroup to all other palaeognaths group of small, primarily cursorial birds capable of short bursts (HARSHMAN et al., 2008; PHILLIPS et al., 2010; JOHNstoN, 2011; of flight when necessary. Because tinamous are nested within HADDRATH & BAKER, 2012). the clade Paleognathae which is composed of all flightless Some authors have been suggested the flight ability was birds except for tinamous, there is a debate about whether flight lost multiple times in Palaeognathae, which is used to explain in this family is due to retention of the ancestral condition, the clade’s global distribution (HARSHMAN et al., 2008; PHILLIPS or if they re-evolved the ability to fly (e.g., HARSHMAN et al., et al., 2010). However, parsimony-based character analysis 2008; PHILLIPS et al., 2010). This debate is in part due to the suspended this conclusion because there was lack of evidence ambiguity surrounding their phylogenetic relationships to other to suggest homology in the pectoral characters (LIVEZEY & ZUSI, palaeognaths, with some analyses considering them the outgroup 2007). 2 Daisuke SUZUKI, Kentaro CHIBA, Collin S. VANBUREN & Tomoyuki OHASHI Despite numerous morphological phylogenies of Table 1. Examined specimen (skeletons). palaeognaths, little work has been done to document the Institute No. Genus Specis UdsoN ( ) morphology of tinamous. H et al. 1972 described the NMNS A343 Eudromia elegans myology of 22 specimens of 13 species of tinamous, but they NMNS A344 Eudromia elegans did not describe osteological morphology. Many morphological YIO 00321 Eudromia elegans phylogenies use a limited character matrix of <100 characters YIO 00325 Eudromia elegans (CRACRAFT, 1974; JOHNstoN, 2011) and are the only phylogenies YIO 60631 Nothoprocta cinerascens which are able to incorporate fossil taxa that may aid in testing hypotheses of multiple losses of flight. The goal of the present study is therefore to describe the myology and osteology of the Elegant Crested Tinamou (Eudromia elegans) as a tool for future DESCRIPTION work on the phylogeny of extinct and extant palaeognaths. By comparing the anatomy of E. elegans to other extant archosaurs Osteology (both crocodylians and birds), we also highlight similarities and differences in the anatomy that might help future studies begin 1. Scapula (Figures 1, 4) to explore the question of multiple losses of flight or a single gain of flight in palaeognaths from an anatomical perspective. The scapula consists of thick proximal portion composed of the glenoid and acromion processes and an elongated scapular Institutional Abbreviation – KMNH: Kitakyushu blade. The coracoid tubercle, where the coracoid articulates with Museum of Natural History and Human History, Fukuoka, the scapula, is located between the glenoid and the acromion. Japan; YIO: Yamashina Institute of Ornithology, Chiba, Japan. The clavicular facet, which is the articular facet for the furcula, is located distal to the acromion. The glenoid process of the scapula contributes to the glenoid fossa along with the glenoid MATERIALS AND METHODS process of the coracoid, which articulates with the humerus. The scapulo-coracoid joint of is not as large as in Two elegant crested tinamous (Eudromia elegans) (KMNH Eudromia VR 700,000 and YIO 2006-0047) were used. These specimens crocodiles and non-avian dinosaurs, whose joints are tightly are stored in the Kitakyushu Museum of Natural History and connected or sometimes fused. Human History, Kitakyushu City, and Yamashina Institute of The dorsoventral width of the scapular blade is relatively Ornithology, Abiko, Japan. KMNH VR specimen was three years consistent along the proximodistal length of the scapula, and one month old at the time of death, 45 cm in total length and the mediolateral thickness reduces distally. The dorsal (from the nib to the tip of the rectrix), and 695 g in weight. The margin is occupied by the insertion of M. rhomboideus cause of death was systemic amyloidosis. YIO specimen was superficialis laterally and M. rhomboideus profundus medially. one year old at the time of death, total length could not measured The lateral surface of the scapular blade is smooth and lacks (cranial part was removed, but the size was almost same as rugose osteological correlates. Two tendinous origins of M. KMNH VR specimen), and it was 620 g in weight. scapulotriceps attach proximally on the scapular blade. The These specimens did not have any evident morphological muscular origins of M. subscapularis caput laterale and M. abnormarities, and were frozen and stored at ˗20 °C. KMNH scapulohumeralis caudalis cover almost the entire lateral surface VR 700,000 was then thawed before being fixed in 10 % neutral of the distal scapular blade. formalin. YIO 2006-0047 was not fixed after being thawed. The The medial surface of the scapula is proximally occupied visceral organs of KMNH VR 700,000 had been removed during by the origin of M. subscapularis caput mediale. M. serratus autopsy. Significant damage to the left shoulder girdle occurred superficialis cranialis inserts near the proximal end and the during the autopsy at the zoo prior to our dissection. In addition, insertion is oblique relative to the long axis of the scapular blade, we observed five osteological specimens, stored at the National extending cranially from the ventral margin to the dorsal margin. Museum of Nature and Science, and Yamashina Institute of The insertions of both M. serratus superficialis caudalis and M. Ornithology (Table 1). serratus profundus are located on the distal portion. Because the insertions of Mm. serratus are fleshy, there is no obvious The muscles are identified with comparison to HUdsoN et osteological correlate for these