Glorified Dinosaurs: The Origin and Early Evolution of Birds.

“Indeed these are now known from at least nine taxa spread across all the main coelurosaur lineages (Chiappe, 2007), a group identified from thermal modelling as a likely focus for the evolution of avian endothermy (Seebacher, 2003).”

“The taxonomic history of Archaeopteryx is complex, with almost every specimen having been assigned to a different species or even genus at some time (see [2] and [16], for recent reviews).”

“and birds were Triassic and upper Jurassic, respectively [86], and birds from within dinosaurs [86,87].”

“Austroraptor) alongside with crow-sized, winged representatives (i.e. Rahonavis; Forster et al. 1998; Chiappe 2007).”

“This supports the hypothesis that enantiornithines possessed sophisticated aerodynamic abilities, which likely facilitated their rapid diversification within the Cretaceous (Chiappe, 2007).”

“Flight evolved in the ancestor to modern birds during the Mesozoic period (Chiappe 2007) and has allowed this lineage to diversify and occupy habitats throughout the world.”

“Over 30 genera of Early Cretaceous birds have been reported in the last two decades from the Lower Cretaceous of northeastern China (Chiappe 2007, Gao et al. 2008, Zhou et al. 2008, O’Connor et al. 2009), documenting a burst of avian diversification that followed the appearance of the earliest bird…”

“The lack of agreement in the phylogenetic position of Chaoyangia reflects the fragmentary nature of the only known specimen, a problem that is exacerbated by the mosaic distribution of morphologies among Mesozoic Aves (Chiappe 2007).”

“Approximately half of all enantiornithines are known from the Jehol Group, and nearly every species is represented by a partial to nearly complete articulated skeleton, often preserving integument (Zhou and Zhang, 2006a; Chiappe, 2007).”

“Over the past two decades, the Jehol Biota has become world renowned for its diverse avifauna, with both enantiornithines and ornithuromorphs well represented alongside more basal taxa (Zhang et al., 2003; Zhou and Zhang, 2006; Chiappe, 2007).”

“For Neornithes as a whole, the diversification of the crown group is indeed likely to have already taken place in the late Cretaceous.”

“…group exceed all other contemporaneous birds in body size, but also their wings are remarkably long (Zhou and Zhang, 2003) and their skeletons display a notable mosaic of primitive (e.g., broad, non-columnar coracoids) and derived (e.g., reduced minor digit of the hand) characters (Chiappe, 2007).”

“The Cretaceous Enantiornithes is the most taxonomically diverse clade of Mesozoic birds (Chiappe and Walker, 2002; Chiappe, 2007; O’Connor et al., 2011), with more than 60 taxa described worldwide.”

“Early Cretaceous bird taxa far outnumber coeval avian ichnotaxa particularly in central and eastern Asia, which has been a locus of discovery and study of birds from this epoch (You et al. 2006; Zhou and Zhang 2004; Chiappe 2007).”

“These articulate to a distal rod-like pygostyle, composed of several fused caudal vertebrae, which supports the retricial bulb and associated muscles and feathers for controlling tail fan and contour shape.”

“The discovery of remarkable fossil avian faunas from China (Chiappe, 2007) has stimulated interest in feather evolution (Maderson and Homberger, 2000; Sawyer and Knapp, 2003; Feduccia et al., 2005).”

“All modern birds, whether volant or flightless, descended from a common flight-capable ancestor (Feduccia 1996; Chiappe 2007) and passage through this flying stage appears to have profoundly affected the anatomy and physiology of birds.”

“increased dramatically, such that our understanding of avian evolution during the Mesozoic is much improved (Zhou 2004; Chiappe 2007; Zhou & Zhang 2007).”

“The majority of Chinese enantiornithines are from the Early Cretaceous Jehol Biota, 130e120 Ma, in northeastern China, which has provided more information regarding early avian evolution than any other in the world (Zhou et al., 2003; Chiappe, 2007; Zhou and Wang, 2010; O'Connor et al., 2013; Pan et al., 2013).”

“…has transformed our understanding of the earliest phases of the avian evolution (e.g., Sanz et al. 1988, 1995, 1996; Chiappe and Calvo 1994; Hou 1997; Clarke and Norell 2002; Zhou and Zhang 2002; Zhou et al. 2005, 2009; Chiappe 2007; Zhang et al. 2008; O’Connor et al. 2010; Brusatte et al. 2015).”

“For example in a major book Glorified Dinosaurs, Chiappe (2007) states (and illustrates), “Fossils seemingly pertaining to galliforms, anseriforms, pelecaniforms, gruiforms, charadriiforms . . . procellariiforms . gaviiforms (loons), and psittaciforms (parrots) have been reported from the Late Cretaceous of nearly eve…”

“1) and is a member of the most speciose clade of Early Cretaceous enantiornithines, the Longipterygidae (Zhang et al. 2000; O’Connor et al. 2009).”

“A new and primitive bird from the Early Cretaceous of China.”

“…called theropods, making them dinosaurs themselves and allowing us to draw a distinction between non-avian dinosaurs (i.e., all those dinosaurs that are not birds) and “avian dinosaurs,” birds themselves (an excellent review of the dinosaurian origin of birds can be found in Chiappe 2007).”

“However, it should also be pointed out that extant archosaurs belong to groups with specialized habits and mode of life, namely a semi-aquatic habit for extant crocodiles and semiaquatic or flying/climbing habit for birds (in particular for basal Ornithothoraces; [96,97]).”

“Any terrestrial vertebrate fossil found from the Jurassic or Cretaceous that is longer than a meter or two is an archosaur, while Mesozoic mammals were tiny, in the size range of mice and shrews today, with a few rare exceptions (e.g., the raccoon-sized Repenomamus; Bowring et al. 1999; Sereno 1999; Hu 2005; Kemp 2005…”

“…have in recent decades embraced the view that birds are derived from terrestrial theropod dinosaurs typified by the dromaeosaur Velociraptor (Chiappe 1999, 2007), and some still hold the view that flight was achieved from the biophysically improbable ground– up model and variations on that…”

“During the last two decades, over 40 species of birds have been named from the Lower Cretaceous Jehol Group Lagerstatten of northeastern China, and discoveries continue at an unprecedented rate (Zhou & Zhang, 2006; Chiappe, 2007; O’Connor, Chiappe & Bell, 2011).”

“The gradual evolution of the avian body plan is fairly well understood and the known diversity of Mesozoic avian stem group representatives is notable (Chiappe 2007; O'Connor et al. 2011; Mayr 2016).”

“Belonging to Order Galiformes, the Phasianidae are therefore known as one distinguished member of agro-ecosystems, and now have been become extremely successful ecotypes to adapt to different complex contexts (Naish, 2011).”

“However, Chiappe et al. (2008; see also Chiappe, 2007) stated that the features distinguishing specimens assigned to Jinzhouornis from C. sanctus actually represent variations at the intraspecific level, raising the possibility that both species of Jinzhouornis are junior synonyms of C. sanctus.”

“These and many other interesting subjects have been treated in several comprehensive publications, such as Feduccia (1996, 1999), Elzanowski (2001b, 2002a, b), Chatterjee (1997), Chiappe (2007) and, last, by the present author (Wellnhofer 2008, 2009).”

“Record of the early radiation of Ornithuromorpha, the clade that includes modern birds (Neomithes), has grown rapidly during the last decade (Chiappe, 2007; O’Connor et al., 2010; Brocklehurst et al., 2012).”

“The sequence of events (from arboreal leaping, to parachuting, to gliding, to primitive flying, to advanced manoeuvring flying) are plotted against salient genera involved in the origin of avian flight (modified from Xu et al. 2003; Chiappe 2007; Chatterjee and Templin 2004a; Chatterjee 2002)”

“The group of Enantiornithes (also known as enantiornithines or enantiornitheans) of the Mesozoic period, and extinct at the Cretaceous– Paleogene, looked externally much like actual birds (Chiappe, 2007).”

“During the Mesozoic era, prominent adaptations included a shortened tail and distal vertebral fusion forming the pygostyle (1).”

“Este órgano evolutivamente perdió los dientes y se cubrió con una estructura queratinizada muy ligera, ideal para facilitar, con la reducción de su peso, una de las funciones básicas de las aves: el vuelo (Chiappe 2007).”

“2003), and the aforementioned zoologist Huxley, recognized these similarities (Wagner 1861; Chiappe 2007), which are most apparent in the skeletons of theropod dinosaurs.”

“Birds are different from other dinosaurs, but the peculiarities that we have in mind when we say such things are almost entirely unique to neornithines: it is wiser to say, then, that it is not that birds are different from other dinosaurs; it is that neornithines are different from other dinosaurs. Second, the idea o…”