A Well-Preserved Archaeopteryx Specimen with Theropod Features

“(2006: 42) to ask: ‘Can four million bases [nucleotides] resolve the [avian] tree?’ Fortunately, there are a number of anatomical fields of study that remain virtually untouched in modern phylogenetic contexts (Livezey & Zusi, 2001, 2006), a circumstance of hope in light of the palaeontological discoveries that will n…”

“Nonetheless, Mayr et al. (2005) added a new character state to character 170 from the TWiG dataset.”

“The flight apparatus evolved substantially within birds with the expansion of the pectoral skeleton (Gatesy 2002; Paul 2002; Zhou 2004; Gatesy and Middleton 2006; Chiappe 2007) and its associated musculature (Jasinoski et al. 2006; Baier et al. 2007) and feathers, as well as changes of the tail (Gatesy 1990, 2001b), c…”

“This feature is otherwise known only from the basal avian Rahonavis and deinonychosaurs (Dromaeosauridae and Troodontidae), and its presence in Archaeopteryx provides additional evidence for a close relationship between deinonychosaurs and avians.”

“Mayr G, Pohl B, Peters DS (2005) A well-preserved Archaeopteryx specimen with theropod features.”

“4), very similar to those of Archaeopteryx (Wellnhofer 1992; Mayr et al. 2005), Rahonavis (Forster et al. 1998) and Jeholornis (Zhou & Zhang 2002), but it lacks a high narrow pretibial bone associated primarily with the calcaneum as in neognathous birds (Martin et al. 1980; McGowan 1984).”

“The character had previously been scored ' 1 ' (process present) but the beautifully preserved skull of a new specimen shows that the process is absent (Mayr et al. 2005).”

“Previous study using ultraviolet induced fluorescence photography (3) indicated that the distal left humerus, distal right femur, and proximal right tibiotarsus were restored during preparation.”

“There are no constrictions between the roots and crowns, unlike the teeth of the basal ornithomimosaur Pelecanimimus (LH 7777) and the maniraptorans Mononykus and Archaeopteryx, whose teeth have marked constrictions at the roots (Perle et al., 1994; Perle et al., 1993).”

“Hu D, Hou L, Zhang L, Xu X (2009) A pre-Archaeopteryx troodontid theropod from China with long feathers on the metatarsus.”

“Unlike Archaeopteryx, Jeholornis and Sapeornis, it possesses well-developed uncinate processes, as in Confuciusornis and more derived taxa.”

“Within Coelurosauria, serrations are absent on the teeth of avialans (e.g., Archaeopteryx: Elzanowski & Wellnhofer 1996), many troodontids (Makovicky & Norell 2004), basal ornithomimosaurs (e.g., Pelecanimimus: Perez-Moreno et al. 1994; Shenzhousaurus: Ji et al. 2003; and Harpymimus: Kobayashi & Barsbold 2005a), the o…”

“Primitive long-tailed birds typically possess five (Archaeopteryx; Elzanowski 2002) or six sacrals (e.g. Rahonavis, Jeholornis; Forster et al. 1996; Zhou & Zhang 2003b), while the basal pygostylians Sapeornis and Confuciusornis both possess seven sacral vertebrae (Chiappe et al. 1999; Zhou & Zhang 2003a); the enantior…”

“5; Mayr et al., 2005: fig.”

“…about 110°–120° or more, was mentioned as an avian feature (e.g., Lockley et al., 1992), caused by the single, fused elements formed by the tarsometatarsus, as in all birds, with some exceptions, such as in specimens of Archaeopteryx and Rahona (Forster et al., 1998; Mayr et al., 2005).”

“A distinct constriction is present between the tooth crown and its cylindrical root, as in some other paravians such as Archaeopteryx and Sinovenator (Xu et al., 2002; Mayr et al., 2005).”

“Uncinate processes have also been described in some basal avian species, Confuciusornis (Zhonghe & Lianhai 2002) and may also be present in uncinate processes present material Archaeopteryx (Mayr et al. 2005; see figure 2b; P. L. Manning 2007, personal observation).”

“Anchiornis represents a taxon that is significantly older (∼160 Ma) (7) than the first recognized bird, Archaeopteryx (∼150–155 Ma) (8), but strongly resembles it.”

“…ginglymoid trochlea separated by a constricted shaft, a suite of characters only present in dromaeosaurids (Norell and Makovicky, 2004) including Rahonavis ostromi (Forster et al., 1998; Makovicky et al., 2005; Turner et al., 2007a, 2007c) and not seen in Archaeopteryx (contra Mayr et al., 2005).”

“Deinonychus, Velociraptor) and possibly also the Eichstätt specimen of Archaeopteryx (Mayr et al. 2005; Norell and Makovicky 1999; Ostrom 1969).”

“Coelurosaurian monophyly is supported by the following 11 characters in trees where Zuolong and Tugulusaurus are basal coelurosaurian taxa (numbers refer to characters in Supplemental Data 2 and 3): maxillary fenestra situated posterior to the rostral border of the antorbital fossa (15; also present in Afrovenator [Se…”

“Birds evolved around 150.8 Ma (Mayr et al. 2005), which also corresponds to a peak but clearly predates the J/K boundary.”

“Another basal enantiornithine bird, Shenqiornis, with robust skull and teeth (Wang et al., 2010), is from a distinct unit (Qiaotou Formation) exposed in northern Hebei Province.”

“…is known are either anisodactyl (digit I reversed with respect to II – IV), the plesiomorphic state for all avians more derived than Archaeopteryx (Mayr et al. 2005, 2007), or pamprodactyl (pedal digit I un-reversed) and, in some cases, possibly totipalmate (all digits conjoined by web-bing;…”

“…represent a juvenile stage versus both juveniles and adults are preserved (Houck et al. 1990; Bennett 2008); and (3) locomotory preferences: cursoriality- versus arboreality-derived aerial specializations versus no flapping flight (Feduccia and Tordoff 1979; Mayr et al. 2005; Nudds and Dyke 2010).”

“In this paper we review new material for Gobipteryx (Chiappe et al. 2001), new palatal reconstructions that were proposed for both Hesperornis (Elzanowski 1991) and Archaeopteryx (Elzanowski 2001), and new evidence on structure of os palatinum in Archaeopteryx (Mayr et al. 2005).”

“This is different from the condition in Anchiornis and Archaeopteryx in which the nasal process is straight (Pei et al., 2017).”

“Among extinct avian theropods, a mesethmoid has been reported in enantiornithines (Clarke et al., 2006) and hesperornithiformes (Bühler et al., 1988; Clarke, 2004), although its presence in Archaeopteryx is ambiguous (Mayr et al., 2005).”

“The anisodactyl foot—where the digits II, III and IV are oriented forwards, while digit I is oriented backwards— evolved in early Avialae by the retroversion of the hallux [4,5].”

“The ascending process was previously considered to be a projection of the astragalus in non-avian dinosaurs (Ostrom 1991) and Mesozoic birds (Mayr et al. 2005), since it is always preserved as part of this element.”

“However, these features no longer define Aves, being either present in non-avian dinosaurs (furcula, feathers) or absent in basalmost birds (retroverted pubis, reversed hallux) (Mayr et al. 2005; Witmer 2002).”

“By contrast, the jugal forms a small portion of the ventral margin of the antorbital fenestra in Archaeopteryx (Mayr et al., 2005) and most non-avian dinosaurs (Currie and Zhao, 1993; Barsbold and Osmolska, 1999; Norell et al., 2006; Figs.”

“Indeed, the more an evolutionary segment is investigated, the more aware authors are of ambiguous or homoplastic characters, as seen in the current debate over the phylogenetic positions of taxa around the origin of birds (e.g. Mayr et al. 2005; Turner et al. 2012).”

“The modification of digit II with a hyperextensible joint also discussed for the primitive Late Jurassic basal avian Archaeopteryx [65,66] is an important morphological character for resolving the phylogeny of paravian maniraptorans.”

“in avialans like Archaeopteryx (mayr et al., 2005), the palatine ridge is less pronounced and the anterior pneumatic fossa is enlarged and triangular relative to the condition in Haplocheirus, occupying the majority of the anterodorsal surface of the palatine.”

“…suggests a jugal diverticulum was present in the earliest theropods Eoraptor and Herrerasaurus, in most non-avian theropods, and also in early birds such as Archaeopteryx (Sereno and Novas, 1993:fig.2B; Sereno et al., 1993:fig.2a, b; Mayr et al., 2005:fig.2D; Mayr et al., 2007:fig.5A).”

“2017), provided a bridge for evolutionary biologists to understand the early diversification of birds (Ostrom 1974, 1976; Mayr et al. 2005).”

“To our knowledge, prior to XEA, no phylogenetic analysis of Paraves using maximum parsimony has ever recovered Archaeopteryx in a phylogenetic position other than as a basal avialan [but see Mayr et al. (2005) for an alternative position based on a data set with a restricted number of avialan taxa].”

“2; Mayr et al. 2005; Russell and Bels 2001, fig.”

“Still others believe that maniraptorans evolved and lost flight independently of birds (Paul 2002; Mayr et al. 2005; Xu et al. 2011), so the question of avian versus theropodan affinity remains in debate.”

“the avialan affinity of Archaeopteryx (Mayr et al. 2005; Naish et al. 2011).”

“The Chicago specimen reveals that the fourth lateral process (the ‘jugal’ process 19 ) is rostral to the choanal process (previously depicted as caudal to the choanal process 13 ) and formed a narrow contact with the maxilla near its caudal end, rather than with the jugal, as previously…”

“If the above hypothesis is sustained, it will shed light on the long-debated hallucal orientation of Archaeopteryx (i.e., whether or not the hallux is fully reversed; Middleton, 2001; Mayr et al., 2005, 2007; Feduccia et al., 2007; Mayr and Peters, 2007; Dececchi and Larsson, 2011).”

“The studies by Mayr et al. (2005, 2007) strengthen this relationship, although the diagnostic, stiff ened “ramphorhynchoid” tail of dromaeosaurs is absent in Archaeopteryx, which is primitive in this character.”

“Although these two elements were thought to be separate in most basal birds, like Archaeopteryx , Jeholornis and Sapeornis ( Zhou & Zhang, 2003b ; Mayr, Pohl & Peters, 2005 ; Wang, Stidham & Zhou, 2018 ), fusion of the scapulocoracoid was also reported in the Maxberg, Solnhofen, and Munich…”

“…and opisthopubic Shuvuuia; Hutchinson & Chiappe 1998; Choiniere et al. 2010), Dromaeosauridae (e.g. the propubic Austroraptor and opisthopubic Velociraptor; Norell & Makovicky 1999) and birds (e.g. the mesopubic Archaeopteryx and opisthopubic Confuciusornis; Mayr et al. 2005; Dals€att et al. 2006).”

“Therefore called the ‘Thermopolis specimen’, it was studied in detail by Mayr et al. (2005, 2007) and designated as Archaeopteryx siemensii.”

“…process is slightly higher than the coracoidal glenoid fossa, which would have caused the tendon of m. supracoracoideus to be slightly dorsally displaced relative to its position in Archaeopteryx and non-avialan pennaraptorans (Mayr et al., 2005; Turner et al., 2012; Wang and Zhou, 2018).”

“There is no consensus among ornithologists, whether the famous Archaeopteryx is a bird (O’Connor & Zhou, 2012; Turner et al., 2012) or not (Mayr et al., 2005; Xu et al., 2011).”

“This characteristic has also been reported in the late Jurassic Archaeopteryx, in which it is considered functionally related to a hyperextendible second toe (Mayr et al., 2005:fig.”

“UP are missing from Archaeopteryx; although reported in the 10th Archaeopteryx (Codd et al., 2008), we consider this a misinterpretation of the fossil (originally described in Mayr et al., 2005) and conclude that none are present.”

“Without examining the original specimen fi rst-hand, Feduccia et al. (2007) questioned some observations in our recent description of a new skeleton of Archaeopteryx (Mayr et al. 2005, 2007).”

“forelimb wings of the former by Pei et al. (2020) indicating that Sinornithosaurus was incapable of powered flight.”