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 distinct, the pattern of proximal fusion amongst the carpometacarpal components 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 a few enantiornithines show complete distal fusion amongst metacarpals II and III as well as the aforementioned proximal fusion of your carpometacarpus as observed in Balaur (e.g., Apsaravis, Teviornis, Xiangornis; Clarke Norell, 2002; Kurochkin, Dyke Karhu, 2002; Hu et al., 2012).Semilunate carpal shifted laterally and initially metacarpal sloped proximolaterallyIn Balaur, the semilunate carpal overlaps the entire proximal ends of both metacarpals II and III (Fig. 2A and Fig. S1). In addition, the proximal end from the initially metacarpal inCau et al. (2015), PeerJ, DOI ten.7717/peerj.7/Figure 2 Comparison involving the manus of Balaur along with other paravians. Comparison of the manus of (A) Balaur to those of (B) the enantiornithine Zhouornis; (C) the pygostylian Sapeornis; and (D) the dromaeosaurid Deinonychus, displaying bird-like options of Balaur. (A) soon after Csiki et al.. (2010, Fig. 1, mirrored from original); (B) soon after Zhang et al. (2013, Fig. 7); (C) after Zhou Zhang (2003, Fig. 7); (D) following Wagner Gauthier (1999, Fig. two). All drawn at the identical metacarpal II length. Scale bar: 20 mm (A, D); 10 mm (B, C). Abbreviations: cis, closed intermetacarpal space; cmc, carpometacarpus; d3, decreased third digit; drc, distally JNJ-42165279 web restricted condyles; lsc, laterally shifted semilunate carpal; p1-III, initially phalanx of manual digit 3; p2-III, second phalanx of manual digit three; pec, proximally expanded extensor surface; pnm, proximally narrow metacarpal I; U, ungual; usc, unfused semilunate carpal.Balaur is mediolaterally narrower than the distal finish, generating a proximolaterally sloping medial margin of the metacarpus. In Archaeopteryx and most non-avialan maniraptorans, the proximal end in the first metacarpal isn’t constricted in comparison to the distal end, along with the semilunate carpal overlaps the majority of metacarpal I; meanwhile, the overlap on metacarpal III is absent or restricted towards the medialmost margin in the bone (Fig. 2D; Ostrom, 1976, Fig. ten; Xu, Han Zhao, 2014). Therefore, the position of PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19995790 the semilunate carpal of Balaur represents a lateral shift in comparison with 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 with the proximal finish from the first metacarpal, and a medial margin (“anterior margin”, using Nomina Anatomica Avium nomenclature, see Harris, 2004) that’s variably sloped proximolaterally in extensor view.Cau et al. (2015), PeerJ, DOI ten.7717/peerj.8/Condyles of metacarpals I I restricted for the distal and.