Fig 1.
Slab (BMNHC-PH 919a) (A) and counterslab (BMNHC-PH 919b) (B) of Junornis houi.
Table 1.
Selected lengths (mm) of the skeletal elements and structures of Junornis houi (BMNHC-PH-919a).
Table 2.
OLS multiple regressions used to estimate the body mass (BM), wingspan (B), and lift surface (SL) of BMNHC-PH-919 (see Serrano et al. 2015, 2017).
Fig 2.
Photograph and interpretive drawing of the skull of Junornis houi.
(A, B) BMNHC-PH 919a and (C-D) BMNHC-PH 919b. Abbreviations: d, dentary; dp, dorsal process of maxilla; fp, frontal process of premaxilla; fr, frontal; hy, hyoid; j, jugal; m, maxilla; mp, maxillary process of premaxilla; n, nasal; na, external nares; or, orbit; pa, parietal; pj, postorbital process of jugal; pm, premaxilla; s, splenial; su, surangular.
Fig 3.
Comparison of the sterna of selected enantiornithines.
(A, B), photograph and interpretative drawing of Junornis houi, BMNHC-PH919a; (C), Houornis caudatus; (D), Cathayornis yandica (IVPP 9769); (E), Eocathayornis walkeri (IVPP 10916); (F), “Cathayornis chabuensis” (OFMB-3). Abbreviations: co, coracoid; fu, furcula; it, intermediate trabecula; lt, lateral trabecula; rp, rostral process; sc, scapula; st, sternum; xp, xiphoid process; zp, zyphoid process. The black arrow in C and E points at the concave costal margin of the sternum of Houornis caudatus and Eocathayornis walker. Drawings C-F are not to scale.
Fig 4.
Photograph and interpretative drawing of the pelvic girdle, synsacrum, and caudal vertebrae of Junornis houi (BMNHC-PH919a).
Abbreviations: c, free caudal vertebrae; cp, costal processes of synsacral vertebrae; f, femur; il, ilium; is, ischia; pu, pubis; py, pygostyle; pp, pubic peduncle of ilium; sy, synsacrum; tp, transverse process.
Fig 5.
Photograph and interpretative drawing of the forelimb of Junornis houi.
(A, B) BMNHC-PH919a and (C, D) BMNHC-PH919b. Abbreviations: ad, alular digit; amc, alular metacarpal; h, humerus; mad, major digit; mamc, major metacarpal; mid, minor digit; mimc, minor metacarpal; r, radius; ra, radiale; u, ulna; ul, ulnare.
Fig 6.
Photograph and interpretative drawing of the pes of Junornis houi (BMNHC-PH919a).
Abbreviations: mt I-IV, metatarsal I-IV; I-IV, pedal digits I-IV.
Fig 7.
Morphospace of the flight modes of extant birds.
Morphospace defined by the relationship between wing loading (WL) and aspect ratio (AR). The orange star points at the position of the holotype of Junornis houi (BMNHC-PH919). The values of the 188 modern specimens included in this analysis (gray points) come from Serrano et al. [13]. The inset lists the estimated values of body mass (BM), wingspan (B), lift surface (SL), aspect ratio (AR), and wing loading (WL) of BMNHC-PH919.