Ophichthidae possess similar morphological or osteological characters , so more difficult to be identified 但其外形相似，又缺少鳞片、腹鳍和尾鳍等结构，鉴别特徵较少。
2.
This study : ( 1 ) provides the most detailed osteological and integumentary descriptions on liaoning deinonychosaurs ; ( 2 ) proposes an evolutionary model for feather evolution ; ( 3 ) analyzes the interrelationships of the coelurosauria ; ( 4 ) evaluates the effects of combining information from different parts of the body in reconstructing coelurosaurian evolution , and ( 5 ) discusses the evolutionary trend within the coelurosauria and particularly those features related to the origin of avian flight 本研究： ( 1 )提供了有关辽宁恐爪龙类最详细的骨骼学信息； ( 2 )提出了羽毛演化的一个新模型； ( 3 )综合地分析了虚骨龙类的系统关系； ( 4 )分析身体不同部位的信息对复原系统发育的影响及虚骨龙类各个演化阶段身体不同部位的相对演化程度； ( 5 )讨论了虚骨龙类的演化趋向，尤其是和飞行起源相关特征的变化。
3.
The results show that ( 1 ) loops are in general more variable than stems , and in loops a strong adenine bias are observed : ( 2 ) there does not exist a saturation effect in stems , loops or all positions of the 16s rrna gene fragments : ( 3 ) in the molecular cladogram , bagarius forms a sister group with glyptothorax , and euchiloganis forms a sister group with pareuchiloglanis , and exostoma forms a sister group with glyptosternum : ( 4 ) the phlogenetic positions of pseudecheneis , exostoma and glyptosternum are not recognized ; the glyptosternoid fishes are not monophyly although they are defined by 13 osteological apomorphies ; the incongruence of cladograms between molecular and morphological sets may be caused by less informative sites of the 550 homologous sites ; ( 5 ) e . davidi and e . kishinouyei could be the same species according to the genetic distances ; p . sinensis and p . anteanalis could be too 结果表明： ( 1 )环区平均变异位点较茎区多，有很强的a偏好性； ( 2 )没有替代饱和现象； ( 3 )分子系统树上?属和纹胸?属构成姐妹群，石爬?属和?属构成姐妹群， ?属和原?属构成姐妹群； ( 4 ) ?属、原?属和褶?属的系统发育位置不定， ? ?鱼类并未形成一个单系类群；可能的原因是所得到的16srrna基因片段信息位点太少； ( 5 )青石爬?和黄石爬?可能是同一物种，中华?和前臀?可能是同一物种。
