[PaleoOrnithology • 2025] Chromeornis funkyi • A new small-bodied longipterygid (Aves: Enantiornithes) from the Aptian Jiufotang Formation preserving unusual gastroliths

 

Chromeornis funkyi

O’Connor, Wang, Clark, Kuo, Davila, Wang, Zheng & Zhou, 2025 

 

DOI: doi.org/10.26879/1589 

Artwork: Sunny Dror

 

ABSTRACT

The Longipterygidae are a diverse group of small to medium sized enantiornithine birds with elongate rostra and distally restricted dentition known from the Early Cretaceous Jehol Lagerstätten. The largest taxon, Longipteryx, is known from dozens of specimens but comparatively little is known about small-bodied taxa, sometimes resolved in a subclade, the Longirostravinae. Here we describe a small longipterygid representing a new taxon, Chromeornis funkyi gen. et sp. nov., with a combination of features present in longirostravines and Longipteryx. Cladistic analysis indicates the new species is a member of the Longipteryginae, more closely related to Longipteryx than other longipterygids. The specimen preserves extensive soft tissue including traces of the eyes, skin, and feathers, as well as an unusual mass of gastroliths preserved appressed against the left lateral margin of the cervical vertebrae. Computed-tomography based comparison with the in situ gastric mill preserved in the sympatric ornithuromorphs Archaeorhynchus and Iteravis strongly suggests these gastroliths are not gizzard stones. The absence of a gastric mill in enantiornithines is consistent with pectoral girdle morphology that indicates limited flight capabilities in Early Cretaceous species suggesting ground take off, a necessity of collecting stones, was energetically costly compared to ornithuromorphs. Increases in body mass due to a large gastric mill may have further impeded volant locomotion resulting in a low cost-benefit tradeoff such that this structure was unlikely to evolve during early enantiornithine evolution.

 Keywords: Longipterygidae; new genus; new species; Jehol Biota; regurgitalite; gastrolith; Aves; Avialae.

Class AVES Linnaeus 1758

Clade ORNITHOTHORACES Chiappe 1995

Clade ENANTIORNITHES Walker 1981

Family LONGIPTERYGIDAE Zhang et al. 2000

Chromeornis funkyi gen. et sp. nov.

  

Etymology. Funky Chromeo bird, in honor of the Chromeo Funklordz P-Thugg and Dave 1, who like many birds, make beautiful music. Pronounced crow-me-OR-niss funk-e e.

Diagnosis. A small (estimated 33.5 g) longipterygid (rostrum ~60% of the skull or greater, distally restricted dentition, premaxillary corpus with elongate imperforate rostral end with parallel dorsal and ventral margins, robust pygostyle longer than tarsometatarsus, coracoid with straight lateral margin, humerus with narrow deltopectoral crest) enantiornithine (cranially forked pygostyle with ventrolateral processes, Y-shaped furcula with dorsally excavated rami, proximal humerus with small convex humeral head separated from the dorsal and ventral tubercles by concavities, minor metacarpal projecting farther distally than the major metacarpal, metatarsal IV reduced) distinguishable by the unique combination of the following characters: dentary straight; sternum with slightly splayed lateral trabeculae with asymmetrical fan-shaped distal expansions and short, straight intermediate trabeculae; hand shorter than humerus; alular digit short with small claw; second phalanx of major digit half the length of first phalanx; femur straight.

 Photographs of the counter slab of Chromeornis funkyi gen. et sp. nov. STM7-156.

 Scale bars equal one centimeter.

preserved with over 800 tiny rocks in its throat (visible as the gray mass next to the left of its neck bones). 

Close-up of the mass of rocks in the throat of Chromeornis (the rocks are the gray mass just to the left of the neck bones).  

An illustration showing Chromeornis funkyi gen. et sp. nov.  in life.

Artwork: Sunny Dror

  

Jingmai O’Connor, Xiaoli Wang, Alexander Clark, Pei-Chen Kuo, Ryan Davila, Yan Wang, Xiaoting Zheng, and Zhonghe Zhou. 2025. A new small-bodied longipterygid (Aves: Enantiornithes) from the Aptian Jiufotang Formation preserving unusual gastroliths. Palaeontologia Electronica. 28(3):a56. DOI: doi.org/10.26879/1589 

palaeo-electronica.org/content/2025/5712-longipterygid-enantiornithine-chromeornis

https://palaeo-electronica.org/content/current-in-press-articles/5713-longipterygid-enantiornithine-chromeornis

[PaleoOrnithology • 2024] Neobohaiornis lamadongensis • A New diminutive Species of bohaiornithid enantiornithine (Aves: Ornithothoraces) from the Lower Cretaceous Jehol Group, northern China

Neobohaiornis lamadongensis 

Shen, Clark, Fang, Chen, Jiang, Ji & O’Connor, 2024

DOI: doi.org/10.1038/s41598-024-82869-8 

Researchgate.net/publication/387498440

Abstract

Enantiornithes are the most successful early-diverging avian clade, their fossils revealing important information regarding the structure of Cretaceous avifaunas and the parallel refinement of flight alongside the ornithuromorph lineage that includes modern birds. The most diverse recognized family of Early Cretaceous enantiornithines is the Bohaiornithidae, known from the Jehol Biota in northeastern China. Members of this clade enhance our understanding of intraclade morphological diversity and elucidate the independent evolution of this unique lineage. Here, we report on a new specimen of bohaiornithid, Neobohaiornis lamadongensis gen. et sp. nov., from the Lower Cretaceous Jiufotang Formation in western Liaoning, China. The holotype specimen is considerably smaller than all other known bohaiornithids (roughly half the size of Bohaiornis). The presence of complete fusion in compound elements strongly suggests it represents a mature or nearly mature individual, and therefore substantially increases the known size range of this clade. This specimen further differs from known bohaiornithids in that it exhibits reduced manual unguals and an increased number of sacral vertebrae, which indicates bohaiornithids evolved increased flight capabilities in parallel to other enantiornithine lineages, such as the Longipterygidae. Traces of the plumage, which are rarely preserved in bohaiornithids, reveal the presence of remiges with rounded distal margins and short crural feathers.

 

Holotype of Neobohaiornis lamadongensis gen. et sp. nov. (MHGU-0288).
(A) Photograph; (B) line drawing.

al alular metacarpal, ce cervical vertebrae, co coracoid, d dentary, fr frontal, fe femur, fi fibula, fs fish, fu furcula, h humerus, hy hyoid, il illium, is ischium, mac major metacarpal, mic minor metacarpal, mt I-IV metatarsal I-IV, n nasal, pm premaxilla, pu pubis, py pygostyle, r radiale, sc scapula, st sternum, ti tibiotarsus, u ulna.

Plumage preserved in the holotype of Neobohaiornis lamadongensis gen. et sp. nov. (MHGU-0288).
(A) apices of the feathers extending from the caudal margin of the external nares down the neck; (B) distribution of crural feathers along the left tibiotarsus; (C) A pair of rachis-dominated rectrices (blue arrows); (D) The primary wing feathers preserved on the left wing. ms medial stripe, rd rachis in ‘rachis-dominated’ feathers.

Aves Linnaeus, 1758; [sensu Sereno, 1999].

Ornithothoraces Chiappe, 1995.

Enantiornithes Walker, 1981.

Bohaiornithidae Wang et al., 2014. 

Neobohaiornis lamadongensis gen. et sp. nov.

Diagnosis: Referrable to Enantiornithes based on the presence of the following diagnostic features: a furcula with a ventral margin wider than dorsal margin; a proportionately elongate hypocleidium of the furcula; minor metacarpal projecting distally farther than major metacarpal; metatarsal IV mediolaterally thinner than both metatarsals II and III with the trochlea reduced to a single condyle; and a J-shaped metatarsal I. Referred to the enantiornithine clade Bohaiornithidae based on the presence of  ...

Etymology: The generic name refers to the derived morphology (e.g., reduced alular digit, increased number of sacral vertebrae) of this taxon relative to other bohaiornithids. The specific name refers to the town of Lamadong, near where the fossil was found.

Caizhi Shen, Alexander D. Clark, Hui Fang, Shaokun Chen, Hongxia Jiang, Qiang Ji and Jingmai K. O’Connor. 2024. A New diminutive Species of bohaiornithid enantiornithine (Aves: Ornithothoraces) from the Lower Cretaceous Jehol Group, northern China. Scientific Reports. 14: 31363. DOI: doi.org/10.1038/s41598-024-82869-8

 Researchgate.net/publication/387498440_A_new_diminutive_species_of_bohaiornithid_enantiornithine_from_the_Cretaceous_Jehol_Group_northern_China

[PaleoOrnithology • 2024] Navaornis hestiae • Cretaceous Bird from Brazil informs the Evolution of the Avian Skull and Brain

Navaornis hestiae 

Chiappe, Navalón, Martinelli, Carvalho, Santucci, Wu & Field, 2024

 

 DOI: doi.org/10.1038/s41586-024-08114-4

Abstract

A dearth of Mesozoic-aged, three-dimensional fossils hinders understanding of the origin of the distinctive skull and brain of modern (crown) birds. Here we report Navaornis hestiae gen. et sp. nov., an exquisitely preserved fossil species from the Late Cretaceous of Brazil. The skull of Navaornis is toothless and large-eyed, with a vaulted cranium closely resembling the condition in crown birds; however, phylogenetic analyses recover Navaornis in Enantiornithes, a highly diverse clade of Mesozoic stem birds. Despite an overall geometry quantitatively indistinguishable from crown birds, the skull of Navaornis retains numerous plesiomorphies including a maxilla-dominated rostrum, an akinetic palate, a diapsid temporal configuration, a small cerebellum and a weakly expanded telencephalon. These archaic neurocranial traits are combined with a crown bird-like degree of brain flexion and a bony labyrinth comparable in shape to those of many crown birds but substantially larger. Altogether, the emergent cranial geometry of Navaornis shows an unprecedented degree of similarity between crown birds and enantiornithines, groups last sharing a common ancestor more than 130 million years ago. Navaornis provides long-sought insight into the detailed cranial and endocranial morphology of stem birds phylogenetically crownward of Archaeopteryx, clarifying the pattern and timing by which the distinctive neuroanatomy of living birds was assembled.

Systematic palaeontology

Aves Linnaeus, 1758

Ornithothoraces Chiappe and Calvo, 1994

Enantiornithes Walker, 1981

Navaornis hestiae gen. et sp. nov.

Remarks. We use Aves to refer to all taxa descended from the most recent common ancestor of Archaeopteryx lithographica and crown birds. 

Diagnosis. Enantiornithine with a toothless skull and a combination of the following features: fully fused premaxillae with a convex dorsorostral surface, highly curved jugal, small, comma-shaped quadratojugal, diminutive lacrimal failing to separate the orbit from the antorbital fenestra, parasphenoidal rostrum perforated by a large ovoid fenestra, elongate basipterygoid processes, large and sinusoidal anterior semicircular canal excavating the dorsal margin of the supraoccipital, robust and prominent medial process of the mandible.

Etymology. Navaornis honours William Nava, who discovered the fossil locality in 2004 and the holotype specimen in 2016; the specific epithet hestiae alludes to Hestia, the Greek goddess of architecture, regarded as simultaneously the oldest and the youngest of the Twelve Olympians. Navaornis reflects this duality in that it belongs to an archaic lineage, yet its cranial geometry is essentially modern. 

Luis M. Chiappe, Guillermo Navalón, Agustín G. Martinelli, Ismar de Souza Carvalho, Rodrigo Miloni Santucci, Yun-Hsin Wu and Daniel J. Field. 2024. Cretaceous Bird from Brazil informs the Evolution of the Avian Skull and Brain. Nature. 635, 376–381. DOI: doi.org/10.1038/s41586-024-08114-4

 

[PaleoOrnithology • 2023] Cratonavis zhui • Decoupling the Skull and Skeleton in A Cretaceous Bird with Unique Appendicular Morphologies

 Cratonavis zhui

 Li, Wang, Stidham & Zhou, 2023

 DOI: 10.1038/s41559-022-01921-w

Abstract

The Cretaceous is a critical time interval that encompasses explosive diversifications of terrestrial vertebrates, particularly the period when the earliest-branching birds, after divergence from their theropod ancestors, evolved the characteristic avian Bauplan that led eventually to their global radiation. This early phylogenetic diversity is overwhelmed by the Ornithothoraces, consisting of the Enantiornithes and Ornithuromorpha, whose members evolved key derived features of crown birds. This disparity consequently circumscribes a large morphological gap between these derived clades and the oldest bird Archaeopteryx. The non-ornithothoracine pygostylians, with an intermediate phylogenetic position, are key to deciphering those evolutionary transformations, but progress in their study has been hampered by the limited diversity of known fossils. Here we report an Early Cetaceous non-ornithothoracine pygostylian, Cratonavis zhui gen. et sp. nov., that exhibits a unique combination of a non-avialan dinosaurian akinetic skull with an avialan post-cranial skeleton, revealing the key role of evolutionary mosaicism in early bird diversification. The unusually elongated scapular and metatarsal one preserved in Cratonavis highlights a breadth of skeletal plasticity, stemming from their distinct developmental modules and selection for possibly raptorial behaviour. Mapped changes in these two elements across theropod phylogeny demonstrate clade-specific evolutionary lability.

   

Cratonavis zhui gen. et sp. nov.

 

Zhiheng Li, Min Wang, Thomas A. Stidham and Zhonghe Zhou. 2023. Decoupling the Skull and Skeleton in A Cretaceous Bird with Unique Appendicular Morphologies. Nature Ecology & Evolution. DOI: 10.1038/s41559-022-01921-w

www.eurekalert.org/news-releases/975492

[PaleoOrnithology • 2019] Avimaia schweitzerae • An Early Cretaceous Enantiornithine (Aves) Preserving An Unlaid Egg and Probable Medullary Bone

Avimaia schweitzerae 

Bailleul, O’Connor, Zhang, Li, Wang, Lamanna, Zhu & Zhou, 2019

DOI: 10.1038/s41467-019-09259-x 

Reconstruction by Michael Rothman 

Abstract

Understanding non-crown dinosaur reproduction is hindered by a paucity of directly associated adults with reproductive traces. Here we describe a new enantiornithine, Avimaia schweitzerae gen. et sp. nov., from the Lower Cretaceous Xiagou Formation with an unlaid egg two-dimensionally preserved within the abdominothoracic cavity. Ground-sections reveal abnormal eggshell proportions, and multiple eggshell layers best interpreted as a multi-layered egg resulting from prolonged oviductal retention. Fragments of the shell membrane and cuticle are both preserved. SEM reveals that the cuticle consists of nanostructures resembling those found in neornithine eggs adapted for infection-prone environments, which are hypothesized to represent the ancestral avian condition. The femur preserves small amounts of probable medullary bone, a tissue found today only in reproductively active female birds. To our knowledge, no other occurrence of Mesozoic medullary bone is associated with indications of reproductive activity, such as a preserved egg, making our identification unique, and strongly supported.

Fig. 1 Photograph and line drawing of the holotype of Avimaia schweitzerae, IVPP V25371.
a Photograph of the partial skeleton with feather impressions, and the crushed preserved egg between the pubes; b interpretive line drawing, with white arrows indicating the two fragments extracted for microscopic analysis with a super-imposed CT-scan revealing the egg and underlying elements of the right pelvis in dorsal (synsacrum) and medial (ilium) view.

Gray denotes bones (darker gray indicating poor preservation), blue denotes the egg, and dark gray denotes feather impressions.

 cv caudal vertebra, d digit, dp dorsal process, f fibula, fc fibular crest, fe femur, if ilioischiadic foramen, il ilium, is ischium, l left, mt metatarsal, p pedal phalanx, pu pubis, py pygostyle, r right, ri rib, sy synsacrum, tb tibiotarsus, tm tarsometatarsus, tv thoracic vertebra. 

Scale bar is 1 cm.

  Photograph of the holotype of Avimaia schweitzerae.

(Image by Barbara Marrs) 

Systematic paleontology

Aves Linnaeus, 1758

Pygostylia Chiappe, 2002

Ornithothoraces Chiappe, 1995

Enantiornithes Walker, 1981

Avimaia schweitzerae gen. et sp. nov.

Etymology: The generic name Avi- (bird) maia (mother) refers to the fact the specimen is a female preserved with an egg in the body cavity. Schweitzerae is in honor of Mary Higby Schweitzer for her ground-breaking works on MB and for her role in establishing the field of molecular paleontology.

Holotype: IVPP V25371 (Institute of Vertebrate Paleontology and Paleoanthropology), an articulated partial skeleton with some feather traces, consisting of the caudal half of the axial column, the pelvis, and the hind limbs, mostly exposed ventrolaterally (Fig. 1).

Locality and horizon: Near Changma Village, Yumen City, Gansu Province, northwestern China; Lower Cretaceous (lower–middle Aptian) Xiagou Formation10.

Diagnosis: Small-bodied enantiornithine (robust, cranially forked pygostyle, distal condyles of tibiotarsus contacting medially, J-shaped metatarsal I, metatarsal IV mediolaterally reduced relative to metatarsals III and IV, metatarsal IV trochlea reduced to single condyle) with the following autapomorphies: pubis delicate and strongly curved so that the caudal margin is concave throughout; distal end of ischium dorsally curved.

 Reconstruction of the Xiagou Formation with colonial nesting ground of Avimaia schweitzerae.
The female individual dead in the water on the left (with an unlaid egg not visible inside its abdomen), represents the fossilized individual described here.

(Image by Michael Rothman)

Alida M. Bailleul, Jingmai O’Connor, Shukang Zhang, Zhiheng Li, Qiang Wang, Matthew C. Lamanna, Xufeng Zhu and Zhonghe Zhou. 2019.  An Early Cretaceous Enantiornithine (Aves) Preserving An Unlaid Egg and Probable Medullary Bone. Nature Communications. volume 10, 1275. DOI: 10.1038/s41467-019-09259-x 

New Cretaceous Fossil Sheds Light on Avian Reproduction -    english.cas.cn/newsroom/research_news/201903/t20190320_207048.shtml 

New Cretaceous fossil sheds light on avian reproduction  eurekalert.org/e/933b via @EurekAlert

[PaleoOrnithology • 2018] The Origin of the Bird's Beak: New Insights from Dinosaur Incubation Periods

Toothlessness in dinosaurs.

in Yang & Sander, 2018.

  DOI:  10.1098/rsbl.2018.0090 

  twitter.com/RSocPublishing

 Abstract

The toothless beak of modern birds was considered as an adaption for feeding ecology; however, several recent studies suggested that developmental factors are also responsible for the toothless beak. Neontological and palaeontological studies have progressively uncovered how birds evolved toothless beaks and suggested that the multiple occurrences of complete edentulism in non-avian dinosaurs were the result of selection for specialized diets. Although developmental biology and ecological factors are not mutually exclusive, the conventional hypothesis that ecological factors account for the toothless beak appears insufficient. A recent study on dinosaur incubation period using embryonic teeth posited that tooth formation rate limits developmental speed, constraining toothed dinosaur incubation to slow reptilian rates. We suggest that selection for tooth loss was a side effect of selection for fast embryo growth and thus shorter incubation. This observation would also explain the multiple occurrences of tooth loss and beaks in non-avian dinosaur taxa crownward of Tyrannosaurus. Whereas our hypothesis is an observation without any experimental supports, more studies of gene regulation of tooth formation in embryos would allow testing for the trade-off between incubation period and tooth development.

Keywords: incubation periods, developmental biology, tooth formation, edentulism

Figure 1. Toothlessness in dinosaurs.
Consensus cladogram of Archosauria shows that edentulism frequently evolved independently in several lineages. All Ornithischia, Therizinosauroidea, Incisivosaurus and toothed Enantiornithes exhibit partial tooth loss. Ontogenetic edentulism has been reported for the theropod Limusaurus from China [Wang et al., 2017]. Complete edentulism is observed in some pterosaurs, Ornithomimosauria, Caenagnathoidea (including Oviraptoridae), some Mesozoic birds such as Confuciusornis and Gobipteryx, and all extant birds (Neornithes).

Silhouettes were taken from public domain images on phylopic.org.

Tzu-Ruei Yang and P. Martin Sander. 2018. The Origin of the Bird's Beak: New Insights from Dinosaur Incubation Periods.  Biology Letters.   DOI:  10.1098/rsbl.2018.0090  

 twitter.com/RSocPublishing/status/1026157161074905089

[PaleoOrnithology • 2017] Cruralispennia multidonta • A Bizarre Early Cretaceous Enantiornithine Bird with Unique Crural Feathers and An Ornithuromorph Plough-shaped Pygostyle

Cruralispennia multidonta 

Wang, O’Connor, Pan & Zhou, 2017  

DOI: 10.1038/ncomms14141 

Abstract

Enantiornithes are the most successful clade of Mesozoic birds. Here, we describe a new enantiornithine bird, Cruralispennia multidonta gen. et sp. nov., from the Protopteryx-horizon of the Early Cretaceous Huajiying Formation of China. Despite being among the oldest known enantiornithines, Cruralispennia displays derived morphologies that are unexpected at such an early stage in the evolution of this clade. A plough-shaped pygostyle, like that of the Ornithuromorpha, evolved convergently in the Cruralispennia lineage, highlighting the homoplastic nature of early avian evolution. The extremely slender coracoid morphology was previously unknown among Early Cretaceous enantiornithines but is common in Late Cretaceous taxa, indicating that by 131 million years ago this clade had already experienced considerable morphological differentiation. Cruralispennia preserves unusual crural feathers that are proximally wire-like with filamentous distal tips, a new morphotype previously unknown among fossil or modern feathers, further increasing the known diversity of primitive feather morphologies.

Systematic palaeontology

Aves Linnaeus 1758

Ornithothoraces Chiappe 1995

Enantiornithes Walker 1981

Cruralispennia multidonta gen. et sp. nov.

 Etymology. The generic name is derived from Latin ‘Cruralis’ and ‘penna’, referring to the unique feathers on the tibiotarsus; the specific name is derived from Latin ‘mult’ and ‘donta’, referring to the numerous dentary teeth.

 Holotype. IVPP 21711 (housed at the Institute of Vertebrate Paleontology and Paleoanthropology), a nearly fully articulated partial skeleton with associated feathers preserved on a single slab.

Locality and horizon. The new specimen is collected from the Protopteryx-horizon of the Huajiying Formation at the Sichakou Basin, Fengning County, Hebei Province, northeastern China. Four other birds are reported from the same horizon, Eoconfuciusornis, Protopteryx, Eopengornis and Archaeornithura. Stratigraphic correlation and isotopic dating place this horizon at 130.7 Myr ago, late Early Cretaceous.

 Diagnosis. A small enantiornithine with the following unique features: 14 dentary teeth; abbreviated, plough-shaped pygostyle with a pygostyle/tarsometatarsus length ratio of about 0.28; coracoid mediolaterally narrow with the sternal margin measuring only one-quarter of the proximo-distal length; sternum bearing a V-shaped caudal margin and two pairs of subequal caudal trabeculae; manus shorter than the humerus; postacetabular process of the ilium short and strongly ventrally directed; dorsal process of the ischium more distally placed; and pubis without a distal expansion.

Figure 1: Cruralispennia multidonta holotype (IVPP V21711).
 (a) Photograph; (b) line drawing. ca, caudal vertebra; cv, cervical vertebra; il, ilium; is, ischium; lad, left alular digit; lco, left coracoid; lde, left dentary; lfe, left femur; lhu, left humerus; lmd, left major digit; lpd; left pedal digits; lra, left radius; lta, left tarsometatarsus; lti, left tibiotarsus; lul, left ulna; pu, pubis; py, pygostyle; qu, quadrate; rco, right coracoid; rfe, right femur; rhu, right humerus; rmd, right major digit; rpd, right pedal digits; rra, right radius; rsc, right scapula; rta, right tarsometatarsus; rti, right tibiotarsus; rul, right ulna; sk, skull; st, sternum; sy, synsacrum; tv, thoracic vertebra. The white circles (numbered 1–5) and box indicate the locations of the feather and histological samples, respectively. Scale bar, 10 mm. 

Figure 7: Major transitions of fibula and tail morphology across Mesozoic birds.
 The tree, simplified from the strict consensus tree produced by our phylogenetic analysis, is time-scaled using the ‘minimal branch length’ method with a minimum branch length of 1 Myr (see Supplementary Fig. 5 for complete result and node support values). The thick lines indicate the temporal range of fossil taxa. An elongated fibula (in red) is developed in non-ornithothoracine Aves, and the most basal enantiornithines Protopteryx and Pengornithidae; a reduced fibula is convergently evolved in the Ornithuromorpha and derived enantiornithines. Cruralispennia preserves a plough-shaped pygostyle (in pink), which has long been considered unique to Ornithuromorpha (the pink branches). The apparent absence of tail fanning in Cruralispennia indicates that the plough-shaped pygostyle and tail fanning is evolutionarily decoupled in this lineage (the silhouettes were from ref. 47; the reconstruction of tail feathers is on basis of refs 3, 30). 

Min Wang, Jingmai K O’Connor, Yanhong Pan and Zhonghe Zhou. 2017. A Bizarre Early Cretaceous Enantiornithine Bird with Unique Crural Feathers and An Ornithuromorph Plough-shaped Pygostyle. Nature Communications. 8, 14141.  DOI: 10.1038/ncomms14141

[PaleoOrnithology • 2016] Mummified Precocial Bird Wings in mid-Cretaceous Burmese Amber

Figure 2 | DIP-V-15100 photomicrographs. Overview of dorsal wing surface, with claws.

 DOI: 10.1038/ncomms12089 

The mid-Cretaceous Burmese amber deposit of northeastern Myanmar is one of the most prolific and well-studied sources of exceptionally preserved Mesozoic arthropod and plant fossils, but work on feathers from this deposit has just begun. Previous studies of plumage in Cretaceous amber have been based on isolated feathers, leaving taxonomy of the feather-bearers open to debate, and amber in vertebrate bone beds has seldom yielded fossils. Otherwise, Cretaceous feathers are commonly known from carbonaceous compression fossils, and three-dimensional preservation in amber is extremely rare. The combined fossil record of amber and compression fossils has provided many insights into how the feather types associated with modern birds developed, but these glimpses are restricted by preservation in each fossil type. The discovery of two partial bird wings in Burmese amber unites taxonomic and ontogenetic information from osteology with microscopic preservation down to the level of individual feather barbules and their pigment distributions. This new source of information includes integumentary features incompletely known in the compression fossil record.

The studied specimens come from the Angbamo site, Tanai Township, Myitkyina District, Kachin Province of Myanmar. A combination of biostratigraphy and radiometric dating have established an age estimate of 98.8±0.6 Ma for this deposit. The two partial wings (DIP-V-15100 and DIP-V-15101) are tiny, and are preserved within a few cubic centimeters of amber. They were examined by combining synchrotron X-ray micro-CT data for osteology, with standard macro- and microscopic observations of integumentary structures. The small size and poorly-defined articular facets indicate that both specimens were juveniles at the time of death. Although the specimens are similar in gross morphology, proportions and some plumage characteristics, their immaturity limits detailed comparisons. We tentatively suggest that the specimens belong to the same species, and suggest that the following anatomical description should be treated with some caution, given the potential for large-scale ontogenetic changes.

.............

Figure 1: SR X-ray μCT reconstructions of osteology in DIP-V-15100 and DIP-V-15101.
 (a) Mummified DIP-V-15100, showing rachises, skin, muscle and claws. (b) Skeletal morphology of DIP-V-15100, using different density threshold.
(c) Mummified DIP-V-15101, showing rachises, skin, muscle and claws. (d) Skeletal morphology of DIP-V-15101. (e) Reconstruction of osteology based on the CT data.

 al, alular digit; am, alular metacarpal; ma, major digit; mam, major metacarpal; mi, minor digit; mim, minor metacarpal; ra, radius; ul, ulna. Scale bars, 5 mm.    DOI: 10.1038/ncomms12089

  

Lida Xing, Ryan C. McKellar, Min Wang, Ming Bai, Jingmai K. O’Connor, Michael J. Benton, Jianping Zhang, Yan Wang, Kuowei Tseng, Martin G. Lockley, Gang Li, Weiwei Zhang and Xing Xu. 2016. Mummified precocial bird wings in mid-Cretaceous Burmese amber. Nature Communications. 7, 12089. DOI: 10.1038/ncomms12089

ResearchGate.net/publication/304573121_Mummified_precocial_bird_wings_in_mid-Cretaceous_Burmese_amber

Mummified, 99-Million-Year-Old Wings Caught in Amber https://shar.es/1loySs via @LiveScience

Frozen in amber: bird wings from Age of Dinosaurs http://www.cbc.ca/1.3655942

http://themissouriinjuryblog.com/2016/06/28/99-million-year-old-bird-wings-found-encased-in-amber/896

     

Rare Dinosaur-Era Bird Wings Found Trapped in Amber @NatGeo

http://news.nationalgeographic.com/2016/06/dinosaur-bird-feather-burma-amber-myanmar-flying-paleontology-enantiornithes/

[PaleoOrnithology • 2016] Chongmingia zhengi • A New Basal Bird from China with implications for Morphological Diversity in Early Birds

Chongmingia zhengi 

Wang, Wang, Wang & Zhou, 2016 

doi:  10.1038/srep19700 

Abstract

The Chinese Lower Cretaceous Jehol Group is the second oldest fossil bird-bearing deposit, only surpassed by Archaeopteryx from the German Upper Jurassic Solnhofen Limestones. Here we report a new bird, Chongmingia zhengi gen. et sp. nov., from the Jehol Biota. Phylogenetic analyses indicate that Chongmingia zhengi is basal to the dominant Mesozoic avian clades Enantiornithes and Ornithuromorpha, and represents a new basal avialan lineage. This new discovery adds to our knowledge regarding the phylogenetic differentiation and morphological diversity in early avian evolution. The furcula of Chongmingia is rigid (reducing its efficiency), consequently requiring more power for flight. However, the elongated forelimb and the large deltopectoral crest on the humerus might indicate that the power was available. The unique combination of features present in this species demonstrates that numerous evolutionary experimentations took place in the early evolution of powered flight. The occurrence of gastroliths further confirms that herbivory was common among basal birds. The Jehol birds faced competition with pterosaurs, and occupied sympatric habitats with non-avian theropods, some of which consumed birds. Thus, avialan herbivory may have reduced ecological competition from carnivorous close relatives and other volant vertebrates early in their evolutionary history.

Systematic paleontology

Aves Linnaeus, 1758 

Chongmingia zhengi gen. et sp. nov.

Etymology: The generic name is from the Mandarin word Chongming, referring to a Chinese mythological bird. The specific epithet is in honour of Mr. Xiaoting Zheng for his generous contribution in the establishment of the Shandong Tianyu Museum of Nature.

Holotype: STM (Shandong Tianyu Museum of Nature) 9-9, a partial skeleton with associated soft tissues and gastroliths, missing the skull and most of the caudal vertebrae (Fig. 1).

Locality and horizon: Dapingfang, Liaoning Province, China; Jiufotang Formation, Early Cretaceous (Aptian).

Figure 1: Photograph and line drawing of the holotype of Chongmingia zhengi gen. et sp. nov. (STM9-9).

Figure 7: Simplified Mesozoic avian cladogram showing the possible phylogenetic positions of Chongmingia zhengi.
Analysis using the coelurosaurian matrix places Chongmingia within basal avialans and as the sister group to Ornithothoraces (p1), and analysis using the Mesozoic avian matrix resolves Chongmingia as the most basal avialan, except for Archaeopteryx (p2).

See Supplementary Figs 2–4 for complete results. (The skeletal drawing and silhouettes were drawn by Min Wang).  doi:  10.1038/srep19700 

Min Wang, Xiaoli Wang, Yan Wang and Zhonghe Zhou. 2016. A New Basal Bird from China with implications for Morphological Diversity in Early Birds.
Scientific Reports. 6: 19700. DOI:  10.1038/srep19700
ResearchGate.net/publication/291821109_A_new_basal_bird_from_China_with_implications_for_morphological_diversity_in_early_birds

辽宁大平房早白垩世九佛堂组发现热河生物群一类新的基干鸟类化石：郑氏重明鸟

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