A new confuciusornithid bird with a secondary epiphyseal ossification reveals phylogenetic changes in confuciusornithid flight mode

Abstract

The confuciusornithids are the earliest known beaked birds, and constitute the only species-rich clade of Early Cretaceous pygostylian birds that existed prior to the cladogenesis of Ornithothoraces. Here, we report a new confuciusornithid species from the Lower Cretaceous of western Liaoning, northeastern China. Compared to other confuciusornithids, this new species and the recently reported Yangavis confucii both show evidence of stronger flight capability, although the wings of the two taxa differ from one another in many respects. Our aerodynamic analyses under phylogeny indicate that varying modes of flight adaptation emerged across the diversity of confuciusornithids, and to a lesser degree over the course of their ontogeny, and specifically suggest that both a trend towards improved flight capability and a change in flight strategy occurred in confuciusornithid evolution. The new confuciusornithid differs most saliently from other Mesozoic birds in having an extra cushion-like bone in the first digit of the wing, a highly unusual feature that may have helped to meet the functional demands of flight at a stage when skeletal growth was still incomplete. The new find strikingly exemplifies the morphological, developmental and functional diversity of the first beaked birds.

Flight Performance of the Early Cretaceous Bird Confuciusornis sanctus: Evidence from an Exceptionally Preserved Fossil

“…Here we recover key parametric data germane to the flight capabilities of C. sanctus and, for the first time, test hypotheses about the aerial performance of this species through flight modeling. It is important to highlight that there is growing evidence of varying flight modes among confuciusornithids (Wang et al, 2022). Consequently, while our study provides a reliable framework for understanding flight performance in C. sanctus, our conclusions need to be treated with caution if extrapolated to other confuciusornithids, particularly for taxa with different wing outlines such as Eoconfuciusornis zhengi, which appears to lack the distinct elongation of the distal primaries of C. sanctus.…”

“…While these studies have regularly concluded that C. sanctus had some sort of aerial locomotion, these aerodynamic interpretations have ranged from having minimal flight capabilities (Nudds & Dyke, 2010) to being able to perform a degree of gliding (Senter, 2006; or soaring (Peters & Ji, 1999), or to conduct powered flight but limited to short periods of time (Falk et al, 2016). What all these studies have in common is the assumption that C. sanctus was unable to perform prolonged periods of flight (although Wang et al (2022) recently suggested that the basal confuciusornithid Eoconfuciusornis zhengi was adapted for fast, longdistant flight). The present study focuses on a well-preserved, fully feathered specimen (NHMW 1997z0112/0001) of Confuciusornis sanctus (Figs.…”

Transformation of the pectoral girdle in pennaraptorans: critical steps in the formation of the modern avian shoulder joint

“… (A) Anchiornis right scapulocoracoid in lateral view (showing the medial and lateral crash L-shape), furcula in cranial view based on LPM-B00169 and left coracoid in cranial view (showing the subaquatic shape) based on BMNHC PH804 (originally right side) modified after Hu et al (2009) , Pei et al (2017) , and IVPP V14378 based on personal observation; (B) Eosinopteryx based on YFGP-T5197 modified after Godefroit et al (2013) ; (C) Xiaotingia based on STM 27-2 modified after Xu et al (2011) (originally no scale bar); (D) Serikornis based on PMOL-AB00200 modified after Lefèvre et al (2017) . (E) Archaeopteryx right scapulocoracoid based on Mexberg specimen modified after Wellnhofer (2009) , and left coracoid and furcula based on 10th specimen modified after Mayr, Pohl & Peters (2005) ; (F) Jeholornis right scapulocoracoid based on STM after O’Connor et al (2018) , left coracoid based on STM 2-49 and IVPP V13886 modified after Wang et al (2022a) , Wang et al (2022b) , furcula based on YFGP-yb2 modified after Lefèvre et al (2014) ; (G) Sapeornis right scapulocoracoid based on IVPP V12698, furcula and left coracoid based on IVPP V13276 modified after Zhou & Zhang (2003a) , Zhou & Zhang (2003b) ; (H) Confuciusornis right scapulocoracoid based on IVPP V13168 and GMV-2132 modified from Li (2010) , Chiappe et al (1999) ; furcula based on GMV-2131 modified after ( Chiappe et al, 1999 ), left coracoid based on IVPP V16066 modified after Li (2010) . (I) crown birds based on Gallus ; (J) Patagopteryx based on MACN-N-11 modified after Chiappe (2002) ; Rallus subadult (47 days) (K) and juvenile (17 days) (L) modified from Olson (1973) ; (M) Struthio modified from McGowan (1982) .…”

“…1 ) ( Wu et al, 2021a ). Alternatively, separation between the scapula and coracoid evolved independently in Jeholornis , Sapeornis and Ornithothoraces or in a clade formed by Sapeornis and Ornithothoraces (the sister taxon to Ornithothoraces is alternatively resolved as either Sapeornis or the Confuciusornithidae in various published phylogenetic analyses) ( Gianechini et al, 2018 ; Wang, Stidham & Zhou, 2018 ; Agnolín et al, 2019 ; Wang et al, 2022a )–both interpretations are equally parsimonious.…”

“… (A) Eoalulavis based on MCCM-LH-13500 modified after Sanz et al (1996) ; (B) Concornis based on MCCM-LH-1184 ( Serrano et al, 2018 ); (C) Elsornis based on MPD-b 100/201 ( Chiappe et al, 2007 ); (D) Enantiornis based on PVL-4035 (coracoid) and PVL-4055 (scapula) ( Chiappe & Witmer, 2002 ); (E) Bohaiornis based on IVPP V17963 modified after Li et al (2014) ; (F) Dunhuangia based on GSGM-05-CM-030 after Wang et al (2015a) ; (G) Xiangornis based on PMOL-AB00245 after Hu et al (2012) ; (H) Eocathayornis based on IVPP V10916 after Zhou (2002) ; (I) Junornis based on BMNHC PH 919 ( Liu et al, 2017 ); (J) Protopteryx based on BMNHC Ph 1158 after Chiappe et al, 2019a ; Chiappe et al, 2019b ; (K) Shangyang based on IVPP V25033 after Wang & Zhou (2019) ; (L) Parapengornis based on IVPP V18687 after ( Hu, O’Connor & Zhou, 2015 ); (M) Piscivorenantiornis based on IVPP V22582 ( Wang et al, 2022a ; Wang et al, 2022b ). Reconstructed portion marked with dash line; gray color indicates the articular surface for humerus when identical from the specimen during reconstruction.…”