[Paleontology • 2025] Jeholia longchengi • First Mesozoic Scorpion (Scorpiones: Buthida) from China and its Ecological Implications

 

Jeholia longchengi

Xuan, Cai, Y. Huang & D. Huang, 2025 

 DOI: doi.org/10.1016/j.scib.2025.01.035 

 Researchgate.net/publication/388364419

artwork by Jie Sun

 

The top predators of arthropods, such as scorpions, spiders, and centipedes, are less commonly discovered in Mesozoic terrestrial Lagerstätten. Scorpiones belong to the class Arachnida within Arthropoda, with relatively few fossil records [Dunlop, et al., 2023]. The earliest scorpions come from the mid Silurian, and at least some of them have been interpreted as transitional forms from sea to land [Waddington, et al., 2015]. Despite being among the earliest terrestrial arthropods, fossil and living scorpions retain a largely conservative body plan [Dunlop, et al., 2008]. Mesozoic scorpions are mainly from mid-Cretaceous Burmese amber [Xuan, et al., 2023], whereas compression fossils of scorpions normally deposited in the strata are relatively rare except in the Late Triassic Keuper Sandstone Formation of England and the Early Cretaceous Crato Formation of Brazil [Dunlop, et al., 2023].

Three fossil scorpions have been reported from China, including a Miocene scorpion Sinoscorpius shandongensis Hong [1983] from Shandong Province, a Devonian scorpion Hubeiscorpio gracilitarsis Walossek et al. [1990] from Hubei Province, and a Permian scorpion Eoscorpius sp. [Lei et al., 2020] from Wuda, Nei Mongol. The Early Cretaceous Jehol Biota is internationally famous thanks to discoveries of exceptional fossils, including feathered dinosaurs, early birds, diverse mammals and pterosaurs, as well as some arthropod fossils which are mainly represented by insects and a few crustacean species [Chang. et al., 2003]. Here, we document the first scorpion, Jeholia longchengi gen. et sp. nov., from the Yixian Formation of Nei Mongol, uncovering a new member for this terrestrial ecosystem and the first Mesozoic scorpion form China. This scorpion is unusually large among fossil taxa. We tentatively infer the potential predation relationships of the new fossil scorpion and reconstruct the trophic dynamics of Early Cretaceous Jehol palaeo-food webs.

...

General habitus ofJeholia longchengi gen. et sp. nov. 

Order Scorpiones C. L. Koch, 1837.

Parvorder Buthida Soleglad & Fet 2003.

Family incertae sedis.

Jeholia gen. nov. 

Type species. Jeholia longchengi sp. nov., by monotypy.

Etymology. The generic name is derived from the “Jehol Biota”, from where the specimen was discovered. “Jehol” refers to a historical and geographical region in northeastern China. The name is feminine in gender.

Jeholia longchengi sp. nov.

Etymology. The specific name ‘longcheng’ is derived from Longcheng District in Chaoyang City where the fossil was stored.

Paleoecological environment reconstruction of Jeholia longchengi gen. et sp. nov.

artwork by Jie Sun

Qiang Xuan, Chenyang Cai, Yuangeng Huang and Diying Huang. 2025. First Mesozoic Scorpion from China and its Ecological Implications. Science Bulletin.  In Press. DOI: doi.org/10.1016/j.scib.2025.01.035 

 Researchgate.net/publication/388364419_First_Mesozoic_scorpion_from_China 

[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] Imparavis attenboroughi • First Edentulous Enantiornithine (Aves: Ornithothoraces) from the Lower Cretaceous Jehol Avifauna

Imparavis attenboroughi

  Wang, Clark, O'Connor, Zhang, Wang, Zheng & Zhou, 2024

DOI: 10.1016/j.cretres.2024.105867

Artwork: Ville Sinkkonen.

Abstract

Among Mesozoic birds, enantiornithines exhibit great morphological variation, which likely reflects their species diversity, range, and overall success throughout the Cretaceous. The majority of enantiornithines come from the Lower Cretaceous Jehol deposits (130–120 Ma) in northeastern China. In contrast to living birds, most enantiornithines were fully toothed. However, the rostral lengths, appendicular proportions, and pedal morphologies of extant birds can still inform on possible diet, flight mode, and ecology. Both partial (e.g., Longipterygidae) and complete tooth loss (e.g., Yuornis, Gobipteryx) are observed among enantiornithines, with edentulous rostra previously restricted to Upper Cretaceous taxa. Here, we describe the first edentulous enantiornithine from the Lower Cretaceous, Imparavis attenboroughi gen. et sp. nov., indicating a toothless beak evolved in this group 48 Ma earlier than previously recognized. Additionally, we reinterpret Chiappeavis as edentulous which together with the discovery of Imparavis indicates the complete loss of teeth in enantiornithines was not uncommon although still less frequent than observed in ornithuromorphs. The absence of gastroliths in all known enantiornithines suggests that the loss of teeth evolved under different pressures in these two ornithothoracine clades. Differences in rostral occlusion between Imparavis and Chiappeavis suggest they utilized different foraging strategies and possibly diet. Appendicular morphology in Imparavis suggest the capacity for relatively high wing beat frequency and powerful take-off capabilities. Together with the morphology of the hindlimb, we suggest Imparavis was primarily a terrestrial forager that could utilize sudden bursts of flight to escape into arboreal settings as a prey evasion strategy.

Illustration showing the fossil skeleton of Imparavis attenboroughi, alongside a reconstruction of the bird in life.

Artwork: Ville Sinkkonen.

Systematic paleontology

Aves Linnaeus, 1758

Pygostylia Chiappe, 2002

Ornithothoraces Chiappe, 1995

Enantiornithes Walker, 1981

Imparavis attenboroughi gen. et sp. nov.

Locality and horizon. Collected near the village of Toudaoyingzi, Jianchang County, Liaoning Province, PR China; Lower Cretaceous Jiufotang Formation, 120 Ma (Lower Aptian) (He et al., 2004; Pan et al., 2013).

Conclusions: 

Imparavis attenboroughi represents the first known edentulous enantiornithine from the Lower Cretaceous. The discovery of this taxon contributes to the multiple independent evolutionary occurrences of complete tooth loss among Mesozoic birds. The loss of teeth in enantiornithines may be linked to shifts in feeding behavior; however, as yet there is no evidence that this shift was driven by herbivory as is suggested for ornithuromorphs and non-avian dinosaurs. Rostral occlusion in Imparavis ....

Xiaoli Wang, Alexander D. Clark, Jingmai K. O'Connor, Xiangyu Zhang, Xing Wang, Xiaoting Zheng and Zhonghe Zhou. 2024. First Edentulous Enantiornithine (Aves: Ornithothoraces) from the Lower Cretaceous Jehol Avifauna. Cretaceous Research. 159, 105867. DOI: 10.1016/j.cretres.2024.105867

 

[Paleontology • 2023] Meilifeilong youhao • A New toothless Pterosaur from the Early Cretaceous Jehol Biota with Comments on the Chaoyangopteridae

 Meilifeilong youhao  

Wang, Kellner, Jiang, Chen, Costa, Cheng, Zhang, Vila Nova, de Almeida Campos, Sayão, Rodrigues, Bantim, Saraiva & Zhou, 2023

DOI: 10.1038/s41598-023-48076-7 

twitter.com/paleoTaissa

artwork by Maurilio Oliveira

Abstract

The Chaoyangopteridae is a clade of azhdarchoid pterosaurs that stands out in China, particularly in the Jehol Biota, as a Cretaceous group of medium-sized and high-crested pterosaurs. Herein, we describe a new species, Meilifeilong youhao gen. et sp. nov., based on two specimens, one tentatively referred to this taxon. This new species represents the most complete and well-preserved chaoyangopterid recorded to date. Along with a set of characters (low premaxillary crest above the nasoantorbital fenestra extending posteriorly, posterior premaxillary process arched and curving posteriorly, a slightly convex sternal articulation surface of coracoid, and a fibular shaft close to proximal articulation strongly arched posteriorly), this species also provides new information both on the unknown palatal region of this clade, and on the rarely preserved (in place) ear portion with stapes. Moreover, M. youhao sheds light on paleoecological aspects, while also giving new information about the taxonomic diversity of this peculiar group of Jiufotang pterosaurs.

Systematic Paleontology

Pterosauria Kaup, 1834

Pterodactyloidea Plieninger, 1901

Dsungaripteroidea Young, 1964 sensu Kellner 2001, 2003

Azhdarchoidea Nessov 1984, sensu Kellner 2001, 2003

Chaoyangopteridae Lü et al. 2008

Photo (A) and line drawing (B) of the holotype (IVPP V 16059) of Meilifeilong youhao gen. et sp. nov. Arrows indicate preserved soft tissue.
 Abbreviations: at-ax, atlas-axis; cdv, caudal vertebra; cv, cervical vertebra; dca, distal syncarpal; dv, dorsal vertebrae; fe, femur; fi, fibula; gas, gastralia; hu, humerus; il, ilium; isc, ischium; man, mandible; mcI-IV, metacarpal I-IV; mt, metatarsal; obfo, obturator foramen.; paca, preaxial carpal; ph1-3d4, first to third phalanx of manual digit IV; phd 1–3, phalanx of the manual digit IIII; pphd, phalanx of the pedal digit; ppu, prepubis; prca, proximal syncarpal; ptd, pteroid; pu, pubis; ra, radius; ri, rib; sca-cor; scapulocoracoid; sk, skull; sv sacral vertebra; st, sternum; ta, tarsal; ti, tibia; ul, ulna; l, left; r, right.

 Meilifeilong youhao gen. et sp. nov.
Photo (A) and line drawing (B) of the cranial elements of the holotype (IVPP V 16059) 

Meilifeilong gen. nov.

Type species. Meilifeilong youhao.

Etymology. From the Chinese expressions meili—beautiful, fei—fly, and long—dragon, meaning beautiful flying dragon in allusion to the magnificent preservation of the holotype, IVPP V 16059.

Included species. Meilifeilong sanyainus comb. nov.

Diagnosis. Chaoyangopterid with low premaxillary crest above the nasoantorbital fenestra that extends posteriorly; posterior premaxillary process arched and curving posteriorly; humerus about 20% longer than third phalanx of the wing finger (hu/ph1d4 ~ 1.20).

Meilifeilong youhao sp. nov.

Etymology. Youhao, meaning friendship in mandarin, to celebrate the two-decade continuous collaboration between Chinese and Brazilian paleontologists in pterosaur research since 2003.

Holotype. IVPP V 16059, an almost complete skeleton housed at the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), Chinese Academy of Sciences, Beijing, China,

Horizon and locality. Xiaotaizi, Jianchang, Huludao City, western Liaoning China; Jiufotang Formation, Early Cretaceous (Barremian-Aptian).

Diagnosis. Chaoyangopterid pterosaur exhibiting the following autapomorphies: sternal articulation surface of coracoid slightly convex; fibular shaft close to proximal articulation strongly arched posteriorly. The new species can be further distinguished from Meilifeilong sanyainus by the following features: posterior premaxillary process more arched; jugal with lacrimal and postorbital processes at a narrower angle (~ 45° contra ~ 55° in Meilifeilong sanyainus); deeper mandibular symphysis; cervical vertebrae 5 slightly longer than cervical 4; rectangular sternum that is wider than long (square in Meilifeilong sanyainus); scapula comparatively longer relative to the coracoid, metatarsal III and IV proportionally shorter than metatarsals I and II.

 Meilifeilong youhao gen. et sp. nov.

artwork: Maurilio Oliveira

 

Xiaolin Wang, Alexander W. A. Kellner, Shunxing Jiang, He Chen, Fabiana R. Costa, Xin Cheng, Xinjun Zhang, Bruno C. Vila Nova, Diogenes de Almeida Campos, Juliana M. Sayão, Taissa Rodrigues, Renan A. M. Bantim, Antônio A. F. Saraiva and Zhonghe Zhou. 2023. A New toothless Pterosaur from the Early Cretaceous Jehol Biota with Comments on the Chaoyangopteridae. Scientific Reports. 3, 22642. DOI: 10.1038/s41598-023-48076-7

 twitter.com/paleoTaissa/status/1737866080184307713

[Paleontology • 2023] Wulong bohaiensis • Iridescent Plumage in A juvenile dromaeosaurid Theropod Dinosaur

Wulong bohaiensis  Poust, Gao, Varricchio, Wu & Zhang, 2020

in Croudace, Shen, Lü, Brusatte et Vinther, 2023. 

   pan.pl/article/item/app010042022.html

Artwork by Robert Nicholls (Bob Nicholls Art).

Colour reconstructions have provided new insights into the lives of dinosaurs and other extinct animals, by predicting colouration patterns from fossilised pigment-bearing organelles called melanosomes. Although these methods have become increasingly popular, only a small number of dinosaurs have been studied using these techniques, which require exceptional preservation of fossil feathers, leaving open key questions such as whether dinosaurs changed their plumage patterns during ontogeny. Here we reconstruct the feather colouration of an approximately one-year-old individual of the Early Cretaceous dromaeosaurid theropod Wulong bohaiensis, which to our knowledge is the first unequivocal juvenile paravian for which aspects of the original colour has been predicted. Using quadratic discriminant analysis (QDA) and multinomial logistic regression (MLR) on the most comprehensive available datasets, we find strong evidence for iridescent plumage of the forelimb and hindlimb remiges and grey plumage on other portions of the body. This suggests that some juvenile paravians used shiny iridescent feathers for signalling purposes, possibly even before reaching somatic or sexual maturity, and thus we can conclude that this paravian used iridescent signalling for intraspecific communication other than sexual signalling. Finally, our results show that when analysing fossil datasets that are entirely comprised of solid and cylindrical melanosomes QDA consistently outperforms MLR, providing more accurate and higher classification probability colour predictions.

Key words: Dinosauria, Dromaeosauridae, Paraves, Wulong bohaiensis , iridescence, melanosome, palaeocolour, juvenile, colour reconstruction, Cretaceous, China.

Reconstruction of the dromaeosaurid dinosaur Wulong bohaiensis Poust, Gao, Varricchio, Wu, and Zhang, 2020 (DNHM D2933),
from Shangheshou, Chaoyang, Liaoning, China, Early Cretaceous Jiufotang Formation with a minimum age of 120.3Ma.
This illustration broadly depicts iridescent plumage on the limbs and grey feathers on the body. It should be noted that the full extent of the iridescence has been extrapolated in the creation of this illustration, based on the evidence provided by a small but significant distribution of iridescent samples across several limbs of the fossil.

Artwork by Robert Nicholls (Bob Nicholls Art).

 

Angus D. Croudace, Caizhi Shen, Junchang Lü, Stephen L. Brusatte and Jakob Vinther. 2023. Iridescent Plumage in A juvenile dromaeosaurid Theropod Dinosaur. Acta Palaeontologica Polonica.  in press. https://app.pan.pl/article/item/app010042022.html

DOI: 10.4202/app.01004.2022

[Paleontology • 2022] Cranial Osteology and Palaeobiology of the Early Cretaceous Bird Jeholornis prima (Aves: Jeholornithiformes)

Jeholornis 

in Hu, Wang, Fabbri, O’Connor, ... et Benson, 2022. 

DOI: 10.1093/zoolinnean/zlac089

https://twitter.com/tetaneuron

Artistic reconstruction by Michael Rothman

Abstract

Jeholornis is a representative of the earliest-diverging bird lineages, providing important evidence of anatomical transitions involved in bird origins. Although ~100 specimens have been reported, its cranial morphology remains poorly documented owing to poor two-dimensional preservation, limiting our understanding of the morphology and ecology of the key avian lineage Jeholornithiformes, in addition to cranial evolution during the origin and early evolution of birds. Here, we provide a detailed description of the cranial osteology of Jeholornis prima, based primarily on high-quality, three-dimensional data of a recently reported specimen. New anatomical information confirms the overall plesiomorphic morphology of the skull, with the exception of the more specialized rostrum. Data from a large sample size of specimens reveal the dental formula of J. prima to be 0–2–3 (premaxillary–maxillary–dentary tooth counts), contrary to previous suggestions that the presence of maxillary teeth is diagnostic of a separate species, Jeholornis palmapenis. We also present evidence of sensory adaptation, including relatively large olfactory bulbs in comparison to other known stem birds, suggesting that olfaction was an important aspect of Jeholornis ecology. The digitally reconstructed scleral ring suggests a strongly diurnal habit, supporting the hypothesis that early-diverging birds were predominantly active during the day.

Keywords: dentition, diurnality, Jehol Biota, neurocranium

Han Hu, Yan Wang, Matteo Fabbri, Jingmai K O’Connor, Paul G Mcdonald, Stephen Wroe, Xuwei Yin, Xiaoting Zheng, Zhonghe Zhou and Roger B J Benson. 2022. Cranial Osteology and Palaeobiology of the Early Cretaceous bird Jeholornis prima (Aves: Jeholornithiformes). Zoological Journal of the Linnean Society. zlac089. DOI: 10.1093/zoolinnean/zlac089

 twitter.com/tetaneuron/status/1584544150405251074

https://phys.org/news/2022-10-fossil-bird-skull-reconstruction-reveals.html

[Paleontology • 2022] Earliest Evidence for Fruit Consumption and Potential Seed Dispersal by Birds

  

in Hu, Wang, McDonald, et al., 2022. 

DOI: 10.7554/eLife.74751

Abstract

The Early Cretaceous diversification of birds was a major event in the history of terrestrial ecosystems, occurring during the earliest phase of the Cretaceous Terrestrial Revolution, long before the origin of the bird crown-group. Frugivorous birds play an important role in seed dispersal today. However, evidence of fruit consumption in early birds from outside the crown-group has been lacking. Jeholornis is one of the earliest-diverging birds, only slightly more crownward than Archaeopteryx, but its cranial anatomy has been poorly understood, limiting trophic information which may be gleaned from the skull. Originally hypothesised to be granivorous based on seeds preserved as gut contents, this interpretation has become controversial. We conducted high-resolution synchrotron tomography on an exquisitely preserved new skull of Jeholornis, revealing remarkable cranial plesiomorphies combined with a specialised rostrum. We use this to provide a near-complete cranial reconstruction of Jeholornis, and exclude the possibility that Jeholornis was granivorous, based on morphometric analyses of the mandible (3D) and cranium (2D), and comparisons with the 3D alimentary contents of extant birds. We show that Jeholornis provides the earliest evidence for fruit consumption in birds, and indicates that birds may have been recruited for seed dispersal during the earliest stages of the avian radiation. As mobile seed dispersers, early frugivorous birds could have expanded the scope for biotic dispersal in plants, and might therefore explain, at least in part, the subsequent evolutionary expansion of fruits, indicating a potential role of bird–plant interactions in the Cretaceous Terrestrial Revolution.

Seeds preserved in the abdominal area of selected Jeholornis prima specimens.
(A) IVPP V13274 (holotype). (B) STM 2–41.
(C) Close-up image of seeds in IVPP V13274 (A). (D) Gastrolith mass in J. prima STM 2–15.

 Photos in A–D followed figures in O’Connor et al., 2018. 

Scale bars equal 5 mm.

 Han Hu, Yan Wang, Paul G. McDonald, Stephen Wroe, Jingmai K. O'Connor, Alexander Bjarnason, Joseph J Bevitt, Xuwei Yin, Xiaoting Zheng, et al. 2022. Earliest Evidence for Fruit Consumption and Potential Seed Dispersal by Birds. eLife 11:e74751. DOI: 10.7554/eLife.74751

 phys.org/news/2022-08-early-bird-fruit-fossil-earliest.html

[Paleontology • 2021] Nuclear Preservation in the Cartilage of the Jehol Dinosaur Caudipteryx

in Zheng, Bailleul, ... et Zhou, 2021. 

 DOI: 10.1038/s42003-021-02627-8

Abstract

Previous findings on dinosaur cartilage material from the Late Cretaceous of Montana suggested that cartilage is a vertebrate tissue with unique characteristics that favor nuclear preservation. Here, we analyze additional dinosaur cartilage in Caudipteryx (STM4-3) from the Early Cretaceous Jehol biota of Northeast China. The cartilage fragment is highly diagenetically altered when observed in ground-sections but shows exquisite preservation after demineralization. It reveals transparent, alumino-silicified chondrocytes and brown, ironized chondrocytes. The histochemical stain Hematoxylin and Eosin (that stains the nucleus and cytoplasm in extant cells) was applied to both the demineralized cartilage of Caudipteryx and that of a chicken. The two specimens reacted identically, and one dinosaur chondrocyte revealed a nucleus with fossilized threads of chromatin. This is the second example of fossilized chromatin threads in a vertebrate material. These data show that some of the original nuclear biochemistry is preserved in this dinosaur cartilage material and further support the hypothesis that cartilage is very prone to nuclear fossilization and a perfect candidate to further understand DNA preservation in deep time.

Photograph and line drawing of Caudipteryx STM4-3.
 a Photograph of the full slab. b Close-up on the right femur showing the extracted fragment outlined in yellow. c Line drawing of the specimen showing bones in light gray, the mass of gastroliths inside the body in pale gray and integument imprints in dark gray.

cav, caudal vertebrae; cev, cervical vertebrae; Demin. P-S, demineralization and paraffin sections; fi, fibula; G-S SEM, Ground-sections and scanning electron microscopy; il, ilium; is, ischium; l co, left coracoid; l de, left dentary; l fe, left femur; l hu, left humerus; l ra, left radius; l tb, left tibiotarsus; l ul, left ulna; ma, maxilla; mtII, metatarsal II; mtIV, metatarsal IV; pu, pubis; r co, right coracoid; r de, right dentary; r fe, right femur; r hu, right humerus; r ra, right radius; r sc, right scapula; r tb, right tibiotarsus; r ul, right ulna; sk, skull elements; TEM, transmission electron microscopy.

Reconstruction of the Jehol Biota and the well-preserved specimen of Caudipteryx.

Illustration: ZHENG Qiuyang

Xiaoting Zheng, Alida M. Bailleul, Zhiheng Li, Xiaoli Wang and Zhonghe Zhou. 2021. Nuclear Preservation in the Cartilage of the Jehol Dinosaur Caudipteryx. Communications Biology. 4: 1125. DOI: 10.1038/s42003-021-02627-8

Organic molecule remnants found in nuclei of ancient dinosaur cells

 eurekalert.org/news-releases/929480

[PaleoMammalogy • 2021] Fossiomanus sinensis & Jueconodon cheni • Fossoriality and Evolutionary Development in Two Cretaceous Mammaliamorphs

Fossiomanus sinensis & Jueconodon cheni 

Mao, Zhang, Liu & Meng, 2021

 DOI: 10.1038/s41586-021-03433-2

Abstract

Mammaliamorpha comprises the last common ancestor of Tritylodontidae and Mammalia plus all its descendants. Tritylodontids are nonmammaliaform herbivorous cynodonts that originated in the Late Triassic epoch, diversified in the Jurassic period and survived into the Early Cretaceous epoch. Eutriconodontans have generally been considered to be an extinct mammalian group, although different views exist. Here we report a newly discovered tritylodontid and eutriconodontan from the Early Cretaceous Jehol Biota of China. Eutriconodontans are common in this biota, but it was not previously known to contain tritylodontids. The two distantly related species show convergent features that are adapted for fossorial life, and are the first ‘scratch-diggers’ known from this biota. Both species also show an increased number of presacral vertebrae, relative to the ancestral state in synapsids or mammals, that display meristic and homeotic changes. These fossils shed light on the evolutionary development of the axial skeleton in mammaliamorphs, which has been the focus of numerous studies in vertebrate evolution and developmental biology. The phenotypes recorded by these fossils indicate that developmental plasticity in somitogenesis and HOX gene expression in the axial skeleton—similar to that observed in extant mammals—was already in place in stem mammaliamorphs. The interaction of these developmental mechanisms with natural selection may have underpinned the diverse phenotypes of body plan that evolved independently in various clades of mammaliamorph.

Holotypes of Fossiomanus sinensis (JZMP-2107500093) 

 Systematic palaeontology

Synapsida Osborn, 1903

Cynodontia Owen, 1861

Mammaliamorpha Rowe, 1988

Tritylodontidae Cope, 1844

Fossiomanus sinensis gen. et sp. nov.

Holotype. A skeleton with broken skull and partial dentition (accessioned as Jinzhou Paleontological Museum (JZMP)-2107500093).

Locality and horizon. Jiufotang Formation at Lamadong, Jianchang (Liaoning province, China); Aptian stage (about 120 million years old) (Supplementary Information).

Etymology. Fossio, ‘digging’ and manus ‘hand’; sinensis, ‘from China’ (Latin).

The dioramic landscape illustrates the Early Cretaceous Jehol Biota with emphasis on mammaliamorphs.

Illustration: Chuang Zhao

Mammaliaformes Rowe, 1988

Mammalia Linnaeus, 1758

Eutriconodonta Kermack, Mussett and Rigney, 1973

Jueconodon cheni gen. et sp. nov.

Holotype. A nearly complete skeleton with dentition (accessioned at the Beipiao Pterosaur Museum of China, catalogue number ZGY0052) (Figs. 1, 2, Extended Data Figs. 5–8).

Locality and horizon. Yixian Formation at Jianshangou, Beipiao (Liaoning province, China); Early Barremian to Early Aptian stage (Supplementary Information).

Etymology. Jue, digging (Chinese pinyin); conodon, cuspate tooth (Latin); the specific name is for Y. Chen, who collected the holotype.

Fangyuan Mao, Chi Zhang, Cunyu Liu and Jin Meng. 2021. Fossoriality and Evolutionary Development in Two Cretaceous Mammaliamorphs. Nature.  DOI: 10.1038/s41586-021-03433-2

 

Dig This: Two New Burrowing Mammal Ancestors Discovered

 amnh.org/explore/news-blogs/research-posts/burrowing-mammal-ancestors-discovered

Scientists discover two new species of ancient, burrowing mammal ancestors

 phys.org/news/2021-04-scientists-species-ancient-burrowing-mammal.html

[Paleontology • 2020] Kompsornis longicaudus • A New Jeholornithiform exhibits the Earliest Appearance of the Fused Sternum and Pelvis in the Evolution of Avialan Dinosaurs

Kompsornis longicaudus

 Wang, Huang, Kundrát, Cau, Liu, Wang & Ju, 2020

 DOI: 10.1016/j.jseaes.2020.104401 

 theropoda.blogspot.com 

  twitter.com/TheropodaBlog

Highlights: 

• A new genus of Jeholornithiformes from the Jehol Biota in China.

• The earliest occurrence of fused pelvis during the evolution from non-avian dinosaurs to birds.

• The skeletal reinforcement occurred during the juvenile ontogeny in some Jeholornithiformes.

Abstract

A new jeholornithiform - Kompsornis longicaudus gen. et sp. nov. - is reported based on a nearly complete specimen from the Jehol Biota in western Liaoning, China. Comprehensive comparisons and phylogenetic analysis, including all published species of Jeholornithiformes, are provided and indicate that Shenzhouraptor sinensis, Jeholornis prima, Jixiangornis orientalis, Jeholornis palmapenis and Jeholornis curvipes are all valid species of this clade, but that Dalianraptor cuhe is regarded as a nomen dubium. In particular, K. longicaudus possesses completely fused sternum and pelvis, a combination of advanced features that is for the first time recognized among jeholornithiforms and non-pygostylian avialans. The osteohistological investigation suggests that the skeletal reinforcement occurred during the juvenile ontogeny in some Jeholornithiformes. Therefore, the new discovery further enriches the diversity of Jeholornithiformes and suggests an unexpected developmental disparity in ossification patterns along the lineage from non-avian dinosaurs to birds.

Keywords: Early Cretaceous, Jehol Biota, Jeholornithiformes, osteohistology, taxonomy

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 DOI: 10.1016/j.jseaes.2020.104401  theropoda.blogspot.com 

Dinosauria Owen, 1842

Theropoda sensu Gauthier, 1986

Maniraptora Gauthier, 1986

Avialae Gauthier, 1986

Jeholornithiformes Zhou and Zhang, 2006

Genus Kompsornis gen. nov.

Etymology. Kompsornis is composed of the Greek ‘Kompsos’ (elegant or pretty) and ‘ornis’ (bird).

  Kompsornis longicaudus sp. nov. 

Etymology. The term longicaudus is composed of Latin ‘longis’ (elongated) and ‘caudus’ (tail), referring to the relatively long tail vertebrae of the type specimen.

 Type locality and horizon. Jiufotang Formation, Lingyuan locality, western Liaoning, China.

Xuri Wang, Jiandong Huang, Martin Kundrát, Andrea Cau, Xiaoyu Liu, Yang Wang and Shubin Ju. 2020. A New Jeholornithiform exhibits the Earliest Appearance of the Fused Sternum and Pelvis in the Evolution of Avialan Dinosaurs. Journal of Asian Earth Sciences. In Press, 104401. DOI: 10.1016/j.jseaes.2020.104401

  twitter.com/TheropodaBlog/status/1264051294899224576

twitter.com/TheropodaBlog/status/1264102251251085314

theropoda.blogspot.com/2020/05/leleganza-di-kompsornis-longicaudus.html

[PaleoOrnithology • 2020] Khinganornis hulunbuirensis • A New Advanced Ornithuromorph Bird from Inner Mongolia documents the northernmost Geographic Distribution of the Jehol Paleornithofauna in China

Khinganornis hulunbuirensis

Wang, Cau, Kundrát, Chiappe, Ji, Wang, Li & Wu, 2020

DOI: 10.1080/08912963.2020.1731805 

 theropoda.blogspot.com

ABSTRACT

We describe a new taxon of advanced ornithuromorph bird, Khinganornis hulunbuirensis gen. et sp. nov., from the previously unreported Pigeon Hill locality of the Lower Cretaceous Longjiang Formation in the northern Greater Khingan Range area of Inner Mongolia, China. A cladistics analysis resolves K. hulunbuirensis as the sister group of a clade formed by Changzuiornis and Iteravis among ornithuromorphs. The osteohistological analysis indicates that K. hulunbuirensis is the first ornithuromorph that maintained an uninterrupted growth during a longer period characterised by slow deposition of low-vascularised and terminal avascular bone tissue. The relatively long hindlimbs and elongate pedal digits with long proximal phalanges suggest a wading and amphibious ecology for the new bird. The discovery of K. hulunbuirensis represents the first occurrence of Jehol birds in the Greater Khingan Range and documents the northernmost known geographic distribution of the celebrated avifauna in China. The new record implies more extended palaeogeographic range for the early diversification of Mesozoic birds on the eastern side of Laurasia.

KEYWORDS: Early Cretaceous, Longjiang formation, Jehol Biota, Ornithuromorpha, growth strategy

the holotype of Khinganornis hulunbuirensis gen. et sp. nov., SGM-AVE-2017001. A, slab-A; B, slab-B.

Abbreviations: ce, cervical vertebrae; co, coracoid; cv, caudal vertebrae; f, femur; fu, furcula; h, humerus; il, ilium; is, ischium; lr, left radius; lu, left ulna; ma, manus; pd, pedal digits; pu, pubis; rr, right radius; ru, right ulna; s, scapula; sk, skull; st, sternum; t, tibiotarsus; tm, tarsometatarsus. 

Scale bar = 2 cm.

Systematic palaeontology 

Class: Aves Linnaeus, 1758 

Pygostylia Chiappe, 2002 

Ornithothoraces Chiappe, 1995 

Ornithuromorpha Chiappe, 2002 

Genus: Khinganornis gen. nov.

 Type species: Khinganornis hulunbuirensis sp. nov. 

Derivation of name: The genus name is derived from the Greater Khingan Range in northeastern China, referring to the first fossil bird uncovered from the Greater Khingan Range at the time of publication. 

Khinganornis hulunbuirensis sp. nov.

Derivation of name: The species name refers to the fossil site located in Hulunbuir City.

Xuri Wang, Andrea Cau, Martin Kundrát, Luis M. Chiappe, Qiang Ji, Yang Wang, Tao Li and Wenhao Wu. 2020. A New Advanced Ornithuromorph Bird from Inner Mongolia documents the northernmost Geographic Distribution of the Jehol Paleornithofauna in China. Historical Biology: An International Journal of Paleobiology. DOI: 10.1080/08912963.2020.1731805 

 theropoda.blogspot.com/2020/02/khinganornis-wang-cau-kundrat-chiappe.html