Few non-avialan theropod lineages (e.g., Avimimus

few non-avialan theropod lineages (e.g., Avimimus, Mononykus; Kurzanov, 1981; Perle et al., 1993), and in pygostylians (e.g., Ventral surfaces {of the|from the|in the|on the|with 2001) vs. anatomically-realistic 3D musculoskeletal models (Delp et al., 1999; Arnold et al. Confuciusornis, Xiangornis; Chiappe et al., 1999; Hu et al., 2012). Scale bar: 20 mm (A, D); 10 mm (B, C). Abbreviations: cis, closed intermetacarpal space; cmc, carpometacarpus; d3, reduced third digit; drc, distally restricted condyles; lsc, laterally shifted semilunate carpal; p1-III, 1st phalanx of manual digit 3; p2-III, second phalanx of manual digit 3; pec, proximally expanded extensor surface; pnm, proximally narrow metacarpal I; U, ungual; usc, unfused semilunate carpal.Balaur is mediolaterally narrower than the distal end, generating a proximolaterally sloping medial margin on the metacarpus. In Archaeopteryx and most non-avialan maniraptorans, the proximal finish in the initially metacarpal will not be constricted when compared with the distal end, and the semilunate carpal overlaps most of metacarpal I; meanwhile, the overlap on metacarpal III is absent or restricted for the medialmost margin of the bone (Fig. 2D; Ostrom, 1976, Fig. 10; Xu, Han Zhao, 2014). Therefore, the position with the semilunate carpal of Balaur represents a lateral shift compared to the condition in other non-avialan maniraptorans, and recalls long-tailed and pygostylian birds exactly where the semilunate carpal has a reduced or absent overlap on metacarpal I and extensively covers each metacarpals II and III (e.g., Confuciusornis, Sinornis, Sapeornis, Enantiornis, Zhouornis; Chiappe et al., 1999; Sereno, Chenggang Jianjun, 2002; Zhou Zhang, 2003; Walker Dyke, 2009; Zhang et al., 2013; see also Xu, Han Zhao, 2014; see Figs. 2BC). As in Balaur, pygostylian birds show a mediolateral constriction in the proximal finish on the very first metacarpal, and also a medial margin ("anterior margin", making use of Nomina Anatomica Avium nomenclature, see Harris, 2004) that's variably sloped proximolaterally in extensor view.Cau et al. (2015), PeerJ, DOI 10.7717/peerj.8/Condyles of metacarpals I I restricted for the distal and.handful of non-avialan theropod lineages (e.g., Avimimus, Mononykus; Kurzanov, 1981; Perle et al., 1993), and in pygostylians (e.g., Confuciusornis, Xiangornis; Chiappe et al., 1999; Hu et al., 2012). In specific, the pattern of proximal fusion among the carpometacarpal elements in Balaur is shared by most basal pygostylians (e.g., Confuciusornis, Sinornis, Sapeornis, Pengornis, Enantiornis, Zhouornis; Chiappe et al., 1999; Sereno, Chenggang Jianjun, 2002; Zhou Zhang, 2003; Zhou, Clarke Zhang, 2008; Walker Dyke, 2009; Zhang et al., 2013; see Figs. 2BC and Fig. S1). Most ornithurines and some enantiornithines show complete distal fusion involving metacarpals II and III along with the aforementioned proximal fusion from the carpometacarpus as seen in Balaur (e.g., Apsaravis, Teviornis, Xiangornis; Clarke Norell, 2002; Kurochkin, Dyke Karhu, 2002; Hu et al., 2012).Semilunate carpal shifted laterally and 1st metacarpal sloped proximolaterallyIn Balaur, the semilunate carpal overlaps the whole proximal ends of both metacarpals II and III (Fig. 2A and Fig. S1). In addition, the proximal finish from the very first metacarpal inCau et al. (2015), PeerJ, DOI 10.7717/peerj.7/Figure two Comparison among the manus of Balaur and also other paravians. Comparison of your manus of (A) Balaur to those of (B) the enantiornithine Zhouornis; (C) the pygostylian Sapeornis; and (D) the dromaeosaurid Deinonychus, showing bird-like functions of Balaur.