尾羽龙(Caudipteryx)的新材料及其重要骨骼特征的补充和修订  

IMPORTANT FEATURES OF CAUDIPTERYX-EVIDENCE FROM TWO NEARLY COMPLETE NEW SPECIMENS

作　　者：周忠和[1] 汪筱林[1] 张福成[1] 徐星[1] 

机构地区：[1]中国科学院古脊椎动物与古人类研究所,北京100044

出　　处：《古脊椎动物学报》2000年第4期241-254,333-342,共14页Vertebrata Palasiatica

基　　金：中国科学院资源与环境研究"九五"重大项目!(编号:KZ951-B1-410);中国科学院创新工程重大项目!(编号:KZCX3-J

摘　　要：Two nearly complete specimens of Caudipteryx preserved a lot more new information about its skeletal anatomy. It has some unexpected bird characters such as the manual digital format of “2-3-2” as in advanced birds rather than the previously recognized “2-3-4” as in Archaeopteryx, Confuciusornis and most theropods, the ungual of the third manual digit is lost; in the skull the nasal opening is larger than the antorbital fenestra, the tail is composed of 22 unfused caudals, there exist only 9 dorsal vertebrae, there are about 12 cervical vertebrae. On the other hand, both new specimens confirm that the pubis of Caudipteryx is anteroentrally rather than posteriorly oriented; the fibula contacts the calcaneum; the quadratojugal contacts both the squamosal and the quadrate. The teeth of Caudipteryx are restricted to the premaxilla in all known specimens.The scapula is expanded at the distal end. The coracoid has a prominent biceps tubercle and possesses an elliptic supracoracoid foramen. Both new specimens appear to confirm that the first metatarsal articulates with the postero edial surface of the second metatarsal and the hallux of the foot is at least partially reversed, therefore suggesting that the ancestor of Caudipteryx had probably possessed the arboreal capability. The reduction of the third manual digit in Caudipteryx also provides further evidence for the homology of the three manual digits in birds and theropod dinosaurs although the reduction of the third digit had obviously appeared many times in the history of dinosaurs and birds. Although Caudipteryx is still accepted as a feathered dinosaur, its newly discovered remarkable birdike characters probably indicate that its phylogenetic position remains a debatable issue.Two nearly complete specimens of Caudipteryx preserved a lot more new information about its skeletal anatomy. It has some unexpected bird characters such as the manual digital format of“2-3-2”as in advanced birds rather than the previously recognized “2-3-4” as in Archaeopteryx, Confuciusornis and most theropods, the ungual of the third manual digit is lost; in the skull the nasal opening is larger than the antorbital fenestra, the tail is composed of 22 unfused caudals, there exist only 9 dorsal vertebrae, there are about 12 cervical vertebrae. On the other hand, both new specimens confirm that the pubis of Caudipteryx is antero-ventrally rather than posteriorly oriented;the fibula contacts the calcaneum; the quadratojugal contacts both the squamosal and the quadrate. The teeth of Caudipteryx are restricted to the premaxilla in all known specimens.The scapula is expanded at the distal end. The coracoid has a prominent biceps tubercle and possesses an elliptic supracoracoid foremen.Both new specimens appear to confirm that the first metatarsal articulates with the postero-medial surface of the second metatarsal and the hallux of the foot is at least partially reversed, therefore suggesting that the ancestor of Caudipteryx had probably possessed the arboreal capability. The reduction of the third manual digit in Caudipteryx also provides further evidence for the homology of the three manual digits in birds and theropod dinosaurs although the reduction of the third digit had obviously appeared many times in the history of dinosaurs and birds. Although Caudipteryx is still accepted as a feathered dinosaur, its newly discovered remarkable bird-like characters probably indicate that its phylogenetic position remains a debatable issue.

关 键 词：鸟类 尾羽龙 标本 骨骼特征 早白垩世 

分 类 号：Q915.865[天文地球—古生物学与地层学]