[Paleontology • 2026] Sauropod teeth from the Khorat Group of Thailand suggest the Faunal Replacement of Sauropod Dinosaurs across the Late Jurassic–Early Cretaceous

Sauropod diversity interpretation throughout the Jurassic–Cretaceous transition of Thailand based on dental evidence in

A, the Late Jurassic (Tithonian); B, the Early Cretaceous (late Valanginian to Barremian), C, the late Early Cretaceous (Aptian to Albian). 

in Chowchuvech, Manitkoon, Chanthasit et Ketwetsuriya. 2026. 

DOI: doi.org/10.1080/08912963.2026.2710631 

  x.com/JobSaurusRex

Illustrations by Pakorn Chotchaiyaporn x.com/Peak4651

ABSTRACT

Sauropod teeth are among the most abundant vertebrate fossils recovered from the Upper Jurassic to Lower Cretaceous Khorat Group of Thailand. However, their taxonomic and palaeoecological significance has not previously been examined in detail. This research presents the first comprehensive taxonomic identification of isolated sauropod teeth from several localities across the Khorat Plateau in Northeastern and Eastern Thailand. Based on morphological analyses, these teeth were assigned to four distinct morphotypes. Additionally, multi-quantitative analyses revealed affinities with four sauropod clades: Mamenchisauridae, Brachiosauridae, Somphospondyli, and Dicraeosauridae. The taxonomic framework recovered in this study is consistent with the broader sauropod fossil record of the Khorat Group and reveals a marked faunal shift across the Jurassic–Cretaceous of Thailand. Mamenchisaurids appeared during the Late Jurassic to the earliest Cretaceous, whereas neosauropods, such as titanosauriforms and diplodocoids, became more prevalent during the Early Cretaceous. These findings suggest new evidence for a major sauropod faunal replacement event, likely driven by ecological changes affecting herbivorous dinosaurs during this crucial timeframe of the Mesozoic.

KEYWORDS: Sauropoda, Mamenchisauridae, Brachiosauridae, Somphospondyli, Diplodocoidea

Sauropod diversity interpretation throughout the Jurassic–Cretaceous transition of Thailand based on dental evidence in A, the Late Jurassic (Tithonian); B, the Early Cretaceous (late Valanginian to Barremian), C, the late Early Cretaceous (Aptian to Albian).

 Illustrations by Pakorn Chotchaiyaporn.

 

Wongwech Chowchuvech, Sita Manitkoon, Phornphen Chanthasit and Chatchalerm Ketwetsuriya. 2026. Sauropod teeth from the Khorat Group of Thailand suggest the Faunal Replacement of Sauropod Dinosaurs across the Late Jurassic–Early Cretaceous. Historical Biology: An International Journal of Paleobiology. DOI: doi.org/10.1080/08912963.2026.2710631 [15 Sep 2026]

   x.com/JobSaurusRex/status/2100237729351221602

  x.com/Peak4651/status/2100259226346201579

[Paleontology • 2026] Kayrasaurus changliensi • A New therizinosaur from the Early Cretaceous Jehol Biota and ecomorphological patterns among early therizinosaurians

 

Kayrasaurus changliensis  Liao, Freimuth, Zanno & Xu, 2026;

Beipiaosaurus inexpectus; Jianchangosaurus yixianensis; Lingyuanosaurus sihedangensis

DOI: doi.org/10.1080/14772019.2026.2710287 

Artwork by Kōhei Futaka. x.com/_HETAKA

 

Abstract

Therizinosauria is a highly specialized clade of maniraptoran theropods, notable for a suite of unusual traits in late-branching taxa. These paradoxical anatomical features contributed to the complex taxonomic history of the clade, which remained unresolved until the discovery of early branching taxa. Here, we describe a new early branching species, Kayrasaurus changliensis, based on a nearly complete, skeletally immature specimen (IVPP V 18597) recovered from the Lower Cretaceous Yixian Formation of western Liaoning, China. This taxon is notably larger than other penecontemporaneous Jehol therizinosaurians (at least 1.6 times larger than the second-largest taxon, Beipiaosaurus inexpectus) and exhibits a unique combination of features (e.g. extremely small and densely packed teeth, cervical centra markedly longer than dorsal centra, and a dorsally extended ‘lip’ on manual ungual IV). We evaluate the phylogenetic position of K. changliensis using an expanded dataset with increased character and taxon sampling. Our results allow us to revise the diagnosis of B. inexpectus and provide new insights into therizinosaurian evolution, provisionally recovering two subclades within Therizinosauridae that are differentiated by their manual ungual morphology. By integrating morphological traits, body mass estimates, and biomechanical data, we infer the possibility of at least two distinct ecological niches among Jehol therizinosaurians. One ecological group, represented by B. inexpectus and possibly K. changliensis, exhibits features indicative of enhanced bite force and a more robust, less cursorial body plan. In contrast, Jianchangosaurus yixianensis and Lingyuanosaurus sihedangensis display traits associated with greater cursoriality and a reliance on forelimb-based foraging. Kayrasaurus changliensis, together with the results of our phylogenetic analysis, provides new insights into the morphological evolution and ecological adaptations of therizinosaurians in the Jehol Biota. However, further analyses and the discovery of more complete, well-preserved specimens are essential to rigorously test and refine these hypotheses. 

Keywords: Early Cretaceous, Liaoning, maniraptoran, morphology, taxonomy

four species of therizinosaurids from the Jehol Biota, China: 
Kayrasaurus changliensis; Beipiaosaurus inexpectus;
Jianchangosaurus yixianensis; Lingyuanosaurus sihedangensis

Artwork by Kōhei Futaka.  x.com/_HETAKA

Systematic palaeontology

Dinosauria Owen, 1842

Theropoda Marsh, 1881

Coelurosauria sensu Gauthier, 1986

Therizinosauria Russell and Dong, 1993

Kayrasaurus changliensis gen. et sp. nov.

Etymology. Kayra, the god of creation in Turkic Shamanism, is the father of Erlik, the god of death, symbolizing its phylogenetic connection to Erlikosaurus; saurus, Greek for lizard. The specific name changliensis is derived from Changli, a historical place name from the Three Kingdoms period, referring to the provenance of the fossil.

Horizon and locality. Dabangou village, Sihetun Area, near Beipiao City, Liaoning Province, P. R. China; Lower Cretaceous (Barremian–Aptian) Yixian Formation (Chang et al., 2017).

Chun-Chi Liao, William J. Freimuth, Lindsay E. Zanno and Xing Xu. 2026. A New therizinosaur from the Early Cretaceous Jehol Biota and ecomorphological patterns among early therizinosaurians. Journal of Systematic Palaeontology. 24(2); 2710287. DOI: doi.org/10.1080/14772019.2026.2710287 [10 Sep 2026]  

x.com/_HETAKA/status/2098404378852102507

[Paleontology • 2026] Nipponopelta yezoensis • A new nodosaurid ankylosaur (Dinosauria: Ornithischia) from the Upper Cretaceous Hikagenosawa Formation in Japan reveals dispersal pattern of Asian nodosaurid ankylosaurs

Nipponopelta yezoensis 

 Oyabu, Kobayashi, Zelenitsky, Fiorillo & Kano, 2026

「ニッポノペルタ・エゾエンシス」DOI: doi.org/10.1016/j.cretres.2026.106477 

Highlights

• Nipponopelta yezoensis is the first ankylosaur formally named from Japan.

• The taxon is more closely related to North American nodosaurids than Asian taxa.

• Coastal environments may have played a role in interregional nodosaurid radiations.

Abstract

Nodosaurid dinosaurs are mainly known from North America and Europe, with rare occurrences in South America and Asia. A partial skull, discovered in a concretion from the upper part of the marine Hikagenosawa Formation (upper Cenomanian) in Yubari City, Hokkaido, Japan, was initially described in 2005 and identified as a nodosaurid based on its dentition and occipital bone morphology. However, its taxonomic status remained unresolved. In this study, three-dimensional CT reconstructions reveal detailed morphological features justifying the naming of a new taxon, Nipponopelta yezoensis gen. et sp. nov., the first named Japanese ankylosaur based on unique characters in the occipital region. Phylogenetic analyses indicate that Nipponopelta yezoeisis is deeply nested within derived North American and European nodosaurids and distantly related to other Asian nodosaurids. Ancestral geographic analysis suggests that Nipponopelta yezoensis and its close relatives originated in Laramidia, Appalachia, and Asia, indicating a wide ancestral area. Habitat reconstruction reveals that Nipponopelta yezoensis preferred marine-influenced environments, likely inhabiting coastal or estuarine areas. This preference for coastal environments played a significant role in its dispersal patterns across different regions.

Keywords: Ankylosauria; Nodosauridae; Cretaceous; Palaeobiogeography; Asia

Nipponopelta yezoensis gen. et sp. nov.

Shumpei Oyabu, Yoshitsugu Kobayashi, Darla K. Zelenitsky, Anthony R. Fiorillo and Manabu Kano. 2026. A new nodosaurid ankylosaur (Dinosauria: Ornithischia) from the Upper Cretaceous Hikagenosawa Formation in Japan reveals dispersal pattern of Asian nodosaurid ankylosaurs. Cretaceous Research. DOI: doi.org/10.1016/j.cretres.2026.106477 [21 August 2026]

https://tiisys.com/blog/2026/09/02/post-202824/

北海道産恐竜化石を「ニッポノペルタ・エゾエンシス」と命名～約1億年前の"海辺の恐竜"が明かす、白亜紀の大陸間移動～（総合博物館　教授　小林快次）

 

[Paleontology • 2026] Climate-extreme-driven Genesis of A Cretaceous Dinosaur Lagerstätte

 

 in Fanti, Consorti, Muscioni, Baldassari, Dinelli, Polentarutti, ... et Chiarenza. 2026. 

DOI: doi.org/10.1016/j.gloplacha.2026.105589 

 x.com/AAlechiarenza

Artwork by palaeoartist Davide Bonadonna

Highlights: 

• Monsoon-driven storms created a Cretaceous dinosaur Lagerstätte.

• Tidal microcouplets yield an unprecedented ∼40-year chronometry.

• Synchrotron micro-XRF/XRD maps refute seasonal varve interpretation.

• Microbial mats enabled rapid sealing and exceptional soft-tissue preservation.

• New genetic model and toolkit for climate event-driven preservation in carbonates.

Abstract

Konservat-Lagerstätten provide exceptional records of past ecosystems, yet the environmental and climatic processes governing their formation in extreme climatic regimes remain a significant, unresolved conundrum. Here we present a novel, process-based mechanism for the Villaggio del Pescatore Konservat-Lagerstätte (northeastern Italy; Late Cretaceous, 80 Ma), which preserves a diverse terrestrial and aquatic biota. Integrating high resolution synchrotron micro-analyses, bulk geochemistry, detailed taphonomy and palaeoclimate simulations we identify a dynamic, monsoon-paced tidal flat ecosystem within a carbonate coastal margin. Field and core records comprise metrescale packages of laterally persistent light–dark laminae; microstratigraphic, spectral and statistical analyses indicate a semidiurnal tidal regime with neap–spring modulation. MicroXRF/XRD mapping reveals that individual microlaminae within couplets share the same elemental inventory refuting a seasonal varve origin. Laminae chronometry, tied to the tidal interpretation, constrains net accumulation of the fossil bearing rhythmites to decadal (∼40 year) timescales. Geochemical proxies record alternating terrigenous rich, high TOC intervals and drier, better oxygenated intervals. Palaeoclimate model ensembles diagnose a vigorous, summer dominated monsoon domain at ∼29° N under greenhouse boundary conditions. We document that episodic monsoon enhanced flood and tropical cyclone pulses delivered sediment, nutrients, carcasses and plant debris to a microbially active, carbonate tidal flat; microbial mats rapidly stabilised and promoted early cementation, enabling exceptional soft tissue preservation. We propose a genetic model in which monsoon–cyclone forcing, tidal trapping and microbial sealing combine to produce decadal, daily resolved vertebrate Lagerstätten in greenhouse settings, offering predictive targets for similar deposits and deep time analogues for modern coastal change.

Keywords: Exceptional fossil preservation, Dinosauria, Crocodylomorpha, Arthropoda, Plants, Italy

“Stormbringer” — palaeoenvironmental reconstruction of Villaggio del Pescatore
The artwork shows a Tethyshadros insularis carcass and an Acynodon crocodylian on a storm-swept tropical tidal flat, beneath the monsoon clouds and a distant cyclone that the study identifies as the engine of the site’s formation.

 by palaeoartist Davide Bonadonna. 

 

Federico Fanti, Lorenzo Consorti, Marco Muscioni, Lorenzo Baldassari, Enrico Dinelli, Maurizio Polentarutti, Giorgio Bais, Alexander Farnsworth, Evelyn Kustatscher, Amalia Spina and Alfio Alessandro Chiarenza. 2026. Climate-extreme-driven Genesis of A Cretaceous Dinosaur Lagerstätte. Global and Planetary Change.  265, October 2026, 105589. DOI: doi.org/10.1016/j.gloplacha.2026.105589

 x.com/AAlechiarenza/status/2074802383733813269

[Paleontology • 2026] Uragasaurus kalasinensis • A New mamenchisaurid Sauropod (Sauropoda: Mamenchisauridae) from the Lower Phu Kradung Formation, Upper Jurassic of northeastern Thailand

Uragasaurus kalasinensis

Nilpanapan, Manitkoon, Suteethorn & Lauprasert, 2026

 

อุรคาซอรัส กาฬสินธุ์เอนซิส  ||  DOI: doi.org/10.1038/s41598-026-49822-3

 Artwork by Pakorn Chotchaiyaporn (Jæsica ẞababi: x.com/Peak4651).

Abstract

Mamenchisauridae is a group of long-necked non-neosauropodan eusauropod dinosaurs that were abundant in East Asia during the Middle to Late Jurassic, but their diversity and geographic distribution outside China remain poorly documented. Here we describe Uragasaurus kalasinensis gen. et sp. nov., a new sauropod dinosaur from the Phu Kradung Formation of northeastern Thailand. The new taxon is based on a well-preserved anterior dorsal vertebra exhibiting a distinctive combination of characters, including a unique Y-shaped configuration formed by the intraprezygapophyseal and single intraprezygapophyseal laminae and a camellate internal pneumatic structure within the centrum revealed by computed tomography (CT). Phylogenetic analyses recover the new taxon as an early-diverging member of Mamenchisauridae. This discovery represents the first formally named mamenchisaurid from Thailand and expands the known geographic distribution of the clade in Southeast Asia. The occurrence of this taxon in the Lower part of the Phu Kradung Formation also contributes to understanding faunal succession within the unit, supports an Upper Jurassic age for the lower part of the formation, and improves understanding of sauropod diversity in Southeast Asia during the Jurassic-Cretaceous transition.

Keywords: Sauropoda, Mamenchisauridae, Upper Jurassic, Phu Kradung Formation, Northeastern Thailand

Holotype of Uragasaurus kalasinensis (PRC 460) and associated materials in the quarry map. PRC 460 Anterior dorsal vertebra in anterior view (a), KS 34-581 anterior dorsal neural arch in anterior view (b), KS 34-602a middle cervical vertebra in ventral view (c), KS 34-586 anterior dorsal neural arch in anterior view, attached by KS 34-588 fibula (d), KS 34-587 coracoid in lateral view (e), KS 34-602b right cervical rib in lateral view (f).

Uragasaurus kalasinensis gen. et sp. nov.

อุรคาซอรัส กาฬสินธุ์เอนซิส

 

Holotype: The isolated anterior dorsal vertebra PRC 460 has been housed at the Palaeontological Research and Education Centre (PRC), Mahasarakham University, Thailand. Following standard paleontological protocols, the vertebrae were mechanically prepared using pneumatic tools and fine brushes to remove the surrounding sediment matrix.

 

Locality: Phu Noi Locality, Kalasin Province, northeastern Thailand (16.93298° N, 103.72327° E).

Horizon: Lower part of the Phu Kradung Formation, Khorat Group.

Age: Latest Jurassic, based on regional stratigraphic correlations and the composition of the vertebrate assemblage; precise chronostratigraphic constraints remain uncertain.

Diagnosis: Uragasaurus kalasinensis gen. et sp. nov. is a mamenchisaurid sauropod diagnosed by the following unique combination of characters (autapomorphy is marked by *): (1) anterior dorsal vertebra with prominent, elongated teardrop-shaped pneumatic fossae on the distal portion of the transverse processes*; (2) intraprezygapophyseal laminae (tprl) meeting ventromedially to form a Y-shaped configuration in anterior view, incorporating a single vertical intraprezygapophyseal lamina (stprl); and (3) shallow, subtriangular pleurocoel lacking an internal septum.

Etymology: The genus name “Uraga” originates from the Sanskrit word उरग, meaning “snake” or “serpent”, referring to the distinguished long neck of the family. The term “saurus” is derived from the Greek word saûros, meaning lizard. The specific epithet refers to Kalasin Province, where the specimens are from.

Holotype of Uragasaurus kalasinensis (PRC 460) and associated materials in the quarry map. PRC 460 Anterior dorsal vertebra in anterior view (a), KS 34-581 anterior dorsal neural arch in anterior view (b), KS 34-602a middle cervical vertebra in ventral view (c), KS 34-586 anterior dorsal neural arch in anterior view, attached by KS 34-588 fibula (d), KS 34-587 coracoid in lateral view (e), KS 34-602b right cervical rib in lateral view (f).
Quarry map showing the spatial distribution of the holotype and associated materials from the Phu Noi Locality (g). PRC 460, representing the new taxon Uragasaurus kalasinensis, is indicated in red. Associated sauropod elements include KS 34-586, KS 34-587, KS 34-588, and KS 34-602a–b, highlighted in yellow, green, blue, purple, and pink, respectively. The inset shows a close-up of the excavation grid highlighting the relative positions of the holotype and nearby associated materials. Each grid square represents 0.75 × 0.75 m.

Life reconstruction of a herd of five individuals of Uragasaurus kalasinensis inhabiting a Late Jurassic forest in Thailand, accompanied by a pair of rhamphorhynchoid pterosaurs and a metriacanthosaurid theropod.

 Artwork by Pakorn Chotchaiyaporn (Jæsica ẞababi).

Apirut Nilpanapan, Sita Manitkoon, Varavudh Suteethorn and Komsorn Lauprasert. 2026. A New mamenchisaurid Sauropod from the Lower Phu Kradung Formation, Upper Jurassic of northeastern Thailand. Scientific Reports. 16: 21205. DOI: doi.org/10.1038/s41598-026-49822-3 [08 July 2026]

 x.com/Peak4651/status/2074902585660919922

[Paleontology • 2026] Zhengheornis buyu • Jurassic Avialan reveals stepwise Evolution of Bony Tail in Birds

Zhengheornis buyu

Wang, Tang, Deng, Dong, L. Xu, X. Xu, M. Lin,  Du, G. Lin, Chen, Zhang & Zhou, 2026 

 

DOI: doi.org/10.1126/sciadv.aeb5202 

Abstract

The evolutionary assembly of the flight-adapted bird body plan encompasses some of the most profound morphological changes in terrestrial vertebrate history. Beyond feathered wings, the short pygostyle-bearing tail has been pivotal to the clade’s ecological success. However, transition from the long bony tail to the short pygostyle-bearing tail remains a mystery, hindered by the scarcity of early branching avialans with transitional morphologies. Here, we report on a new avialan, Zhengheornis buyu, gen. et sp. nov., from the Upper Jurassic of southeastern China, suggesting that the vertebral reduction and shortening preceded pygostyle fusion in early avialan evolution, providing critical evidence for the stepwise evolution of the bird tail. Z. buyu is smaller than all known non-pygostylian paravians, expanding the species and body size diversity of stemward taxa.

Systematics

Theropoda Marsh, 1881  

Maniraptora Gauthier, 1986  

Avialae Gauthier, 1986 

Zhengheornis buyu gen. et sp. nov. 

Etymology: “Zhenghe” (Mandarin), referring to Zhenghe Country, where the holotype specimen was found; “ornis,” bird (Greek); “buyu,” unexpected (Mandarin), from the ancient Chinese book Guoyu, referring to the unique tail and pelvic morphologies preserved in this species. 

Holotype: Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) V34168, an articulated and partially complete skeleton (most limb bones are preserved as molds) with feathers preserved on a slab and counter slab (Fig. 1, figs. S1 and S2, and table S1). 

Locality and horizon: Near Yangyuan Village, Zhenghe Country, Nanping City, Fujian Province; Upper Jurassic, Nanyuan Formation [Tithonian stage]. 

Diagnosis: IVPP V34168 is distinguishable from all other paravians in the following combination of characters (*denotes probable autapomorphy): short tail comprising 15 vertebrae that is shorter than the hindlimb (combined length of femur, tibia, and metatarsal III)*; middle and posterior caudal vertebrae less elongate (opposite to the condition in other long tailed avialans); final two caudal vertebrae box-like*; manual phalanx III-1 shorter than III-2, opposite to the condition in Archaeopteryx and Fujianvenator [the three manual digits of maniraptorans are here identified as I, II, and III, as in (Tamura, et al. 2011)]; manual phalanx III-3 50% longer than III-2 (the length ratio greater than 2 in Anchiornis and Archaeopteryx); slender ischium that has a knob-like, distally located obturator process and lacks the posterior process*; short fibula that terminates far proximal to the ankle; metatarsal I that articulates at the distal third of metatarsal II; metatarsal II that ends far proximal to metatarsal III trochlea; short hallux with an ungual that is smaller than that of other pedal digits; and robust digit II that has the longest non-ungual (II-2) and ungual pedal phalanges.

 

Min Wang, Jianrong Tang, Ke Deng, Liping Dong, Liming Xu, Xing Xu, Min Lin, Honggang Du, Ganmin Lin, Runsheng Chen, Chi Zhang and Zhonghe Zhou. 2026. Jurassic Avialan reveals stepwise Evolution of Bony Tail in Birds. Science Advances. 12(27); DOI: doi.org/10.1126/sciadv.aeb5202 [1 Jul 2026]

[Paleontology • 2026] Jian changmaensis • First non-Avian Theropod (Dromaeosauridae: Microraptorinae) from the Bird-bearing Lower Cretaceous Xiagou Formation of the Changma Basin, Gansu Province, Northwestern China

 

Jian changmaensis 

Zhou, Lamanna, Poust, Li, You & O’Connor, 2026

attacks the early bird Gansus yumenensis 

  

 facebook.com/CarnegieMNH 

 illustration by Lewis LaRosa  x.com/LewisLaRosa, colorized by Jão Canola.

ABSTRACT

Lacustrine sediments of the Lower Cretaceous (lower Aptian) Xiagou Formation exposed near the village of Changma in the Changma Basin of northwestern Gansu Province, China have yielded more than 100 avian partial skeletons, many of which also preserve remnants of soft tissues such as feathers and skin. Collectively, these fossils characterize a rich avifauna dominated by the crownward ornithuromorph Gansus yumenensis Hou and Liu, 1984. Despite this wealth of Early Cretaceous bird material, no skeletal remains of other dinosaurs have been described from Changma to date. Here we report the first non-avian dinosaur body fossil from the Xiagou Formation of the Changma Basin. Consisting of an articulated left pectoral girdle and forelimb lacking the carpus and manus, the specimen pertains to a new dromaeosaurid theropod taxon, Jian changmaensis, gen. et sp. nov. Phylogenetic analysis recovers Jian within Microraptorinae, expanding the definitive fossil record of this clade to include northwestern China. The new Changma microraptorine constitutes an additional similarity between the theropod faunas of the Xiagou Formation of the Changma Basin and penecontemporaneous strata of the Jehol Group of northeastern China. In particular, the Changma theropod assemblage closely resembles that of the Sihedang locality of the Jehol Group in that both include representatives of Microraptorinae and are overwhelmingly dominated by single ornithuromorph taxa that phylogenetic analyses have repeatedly resolved as close relatives. This raises the possibility that the two sites were deposited under comparable paleoenvironmental settings that are otherwise poorly represented at known Jehol localities. 

Key Words: Early Cretaceous, Gansus yumenensis, Jian changmaensis, microraptorine, paleobiogeography, paleoenvironment, phylogeny, Sihedang 

SYSTEMATIC PALEONTOLOGY 

Dinosauria Owen, 1842 

Saurischia Seeley, 1888 

Theropoda Marsh, 1881 

Maniraptora Gauthier, 1986 

Dromaeosauridae Matthew and Brown, 1922 

Microraptorinae Xu, 2002 

Holotype of Jian changmaensis, gen. et sp. nov. (GSGM-D050), an articulated partial left pectoral girdle (scapulocoracoid) and forelimb (humerus, radius, and ulna). A, silhouette of generalized microraptorine dromaeosaurid theropod (courtesy Scott Hartman) showing skeletal elements preserved; B, photograph of specimen as preserved, exposed primarily in dorsomedial (scapulocoracoid), caudodorsal (humerus), and dorsal (radius and ulna) views; C, interpretive line drawing of B; D, detail photograph of scapulocoracoid and proximal end of humerus in caudodorsal view, showing supracoracoid fenestra and other structures; E, interpretive line drawing of D.

Abbreviations: ac, acromion; bc, bicipital crest; C, coracoid; cr, caudal ridge; dep, dorsal epicondyle; dpc, deltopectoral crest; dr, dorsal ridge; ed, epicondylar depression; fs?, fossa for M. supinator?; H, humerus; hh, humeral head; lp, lateral process; ‘mb’, ‘medial bar’; op, olecranon process; R, radius; S, scapula; scb, scapular blade; scf, supracoracoid fenestra; sta, sternal articulation; U, ulna.

Jian changmaensis, gen. et sp. nov.

Diagnosis.—Medium-sized (intermediate in skeletal dimensions between adult specimens of Microraptor zhaoianus and Sinornithosaurus millenii Xu et al., 1999; see Table 2) microraptorine dromaeosaurid theropod characterized by the following three autapomorphies: (1) a coracoid that is proportionally longer relative to the humerus than in any other microraptorine (~36% humerus length; the next closest individuals are the immature Microraptor IVPP V31612, with a value of ~35%, and IVPP V12811, the holotype of Sinornithosaurus, with a value of 33%) (Table 2); (2) humeral distal condyles developed on the cranial surface of this bone (Figs. 2B–C, 3E; a local autapomorphy within Microraptorinae, shared with nonmicroraptorine theropods such as the therizinosaur Erlikosaurus andrewsi Barsbold and Perle, 1980, and Aves); and (3) a well-developed foramen on the ventral aspect of ...

Etymology.—The genus name is for the Jiān (鹣), a one winged bird in Chinese mythology, in reference to the bird-like, possibly volant nature of this microraptorine taxon and the skeletal composition of its holotype (an isolated partial pectoral girdle and forelimb). The specific name is for Changma (昌马), the locality where the holotype was discovered.

 The new microraptor dinosaur Jian changmaensis (left) attacks the early bird Gansus yumenensis (right) in what is now the Changma Basin of northwestern China approximately 120 million years ago. 

 illustration by Lewis LaRosa  x.com/LewisLaRosa,
colorized by Jão Canola.

Ling-Qi Zhou, Matthew C. Lamanna, Ashley W. Poust, Da-Qing Li, Hai-Lu You and Jingmai K. O’Connor. 2026. First non-Avian Theropod (Dromaeosauridae, Microraptorinae) from the Bird-bearing Lower Cretaceous Xiagou Formation of the Changma Basin, Gansu Province, Northwestern China. ANNALS OF CARNEGIE MUSEUM. 92(2); 89–110. [4 June 2026]

https://carnegiemnh.org/wp-content/uploads/2026/06/Jian-changmaensis-Annals-of-Carnegie-Museum.pdf

 facebook.com/CarnegieMNH/posts/1431015332396739

 x.com/LewisLaRosa/status/2062606679980556631

[Paleontology • 2026] Kank australis • New unenlagiid (Theropoda: Unenlagiidae) from the Chorrillo Formation (Late Cretaceous, Maastrichtian), SW Patagonia, Argentina

 

Kank australis

Motta, Rolando, Rozadilla, Agnolín, Egli, Herrera, Chimento, Coco, Tsuihiji, Manabe, Pol & Novas, 2026

 

DOI: doi.org/10.1080/02724634.2026.2656456 

A reconstruction by Gabriel Díaz Yantén

 

ABSTRACT

Unenlagiids constitute a group of paravian theropods up to now represented in Gondwanan landmasses. They are particularly diverse in northern Patagonia, where at least seven species were discovered in Upper Cretaceous beds. In southern Patagonia, by contrast, the record is restricted to a few isolated remains of indeterminate taxa from Argentina and Chile. The aim of the present contribution is to describe an unenlagiid, Kank australis gen. et sp. nov. from the Maastrichtian beds of southern Santa Cruz, southern Patagonia, Argentina. Kank australis is represented by vertebrae, isolated pedal phalanges, and shed teeth. The holotype individual has a unique combination of characters, including a highly pneumatized cervical vertebra with well-developed parapophysis and carotid processes. Further, a pedal phalanx II-2 resembles those of troodontids due the reduction of the distal condyles, and differs from other known unenlagiids. The apomorphic condition of the few available elements suggests that Kank australis was probably distinct from its kin and reinforces the hypothesis that Unenlagiidae was a morphologically disparate clade.

SYSTEMATIC PALEONTOLOGY

DINOSAURIA OWEN, 1842

SAURICHIA SEELEY, 1888

THEROPODA MARSH, 1881

PARAVES SERENO, 1997

UNENLAGIIDAE (Bonaparte, 1999)

KANK AUSTRALIS gen. et sp. nov.

Diagnosis—Medium-sized unenlagiid (phalanges similar in size to Neuquenraptor argentinus estimated in ∼27 kg; Motta, 2023) showing the following combination of characters (autapomorphies marked by an asterisk): (1) dentary teeth having mesial carinae restricted to the apical third of the crown (shared with Austroraptor); (2) labiolingually compressed maxillary teeth “8” in cross-section (shared with Buitreraptor); (3) dentary teeth having a crenulate mesial carina restricted to its apical third; (4) cervicodorsal vertebra having three pneumatic foramina on its ventral surface*; (5) cervicodorsal vertebra having epipophyseal fossa*; and (6) phalanx 2-II showing reduced distal condyles and collateral pits located very close to the anterodorsal corner of the condyles (shared with troodontids).

Etymology—“Kank,” in reference to the “elder Rhea,” who created the constellation Choiols (Southern Cross constellation) in the Aonikenk mythology, and “australis,” which means “from south” in Latin, in reference to the southern latitude where this dinosaur was found.

 

Matías J. Motta, Alexis M. Aranciaga Rolando, Sebastián Rozadilla, Federico L. Agnolín, Federico Brissón Egli, Gerardo P. Álvarez Herrera, Nicolás R. Chimento, Gastón Lo Coco, Takanobu Tsuihiji, Makoto Manabe, Diego Pol and Fernando E. Novas. 2026. New unenlagiid from the Chorrillo Formation (Late Cretaceous, Maastrichtian), SW Patagonia, Argentina. Journal of Vertebrate Paleontology. e2656456. DOI: doi.org/10.1080/02724634.2026.2656456  [28 May 2026]

https://newsroom.taylorandfrancisgroup.com/heron-like-fish-eating-dinosaur-from-70-million-years-ago-discovered-in-argentina

https://www.macnconicet.gob.ar/kank-australis-el-nuevo-raptor-descubierto-en-la-patagonia-argentina

[PaleoOrnithology • 2026] Plumadraco bankoorum • Hyperelongate Ornamental Tail Feathers in A New early Cretaceous enantiornithine Bird

 

Plumadraco bankoorum

Clark, O’Connor, X. Wang, Y. Wang, Pruett-Jones, Zhang, X.Wang, Zheng & Zhou, 2026 

 

DOI: doi.org/10.1371/journal.pone.0347641

Illustration: Ville Sinkkonen

Abstract

Bird diversity is reflected in the abundance and variety of extraordinary plumages. Some of these include elongate, ornamental tail feathers that are typically attributed to either intraspecific communication in monomorphic species or sexual selection in sexually-dimorphic ones. Enantiornithines (Aves: Ornithothoraces) were the most diverse group of birds during the Cretaceous. Importantly, some enantiornithine fossils preserve soft tissues, most often in the form of feathers surrounding the body. Unlike any living bird, many enantiornithine specimens lack tail feathers (rectrices) all together, with the tail region consisting entirely of contour feathers. However, when present, enantiornithine rectrices typically consist of a pair of elongate, ornamental feathers with unusually wide rachises, referred to as rachis-dominated feathers. Here we describe Plumadraco bankoorum gen. et sp. nov., a new bohaiornithid enantiornithine with a pair of exceptionally long rectrices. These tail feathers measure twice the individual’s body length, ending in proportionally small pennaceous rackets, thus adding to the growing diversity of these unusual feathers. The fine preservation of these tail feathers, in comparison to other enantiornithine rectrices, reveals previously unrecognized structural variation that hints at their potential function in courtship displays. Although ornamental feathers in enantiornithines are widely considered sexually dimorphic, determining the selection pressures that shaped them is difficult due primarily to limited soft tissue data. Enantiornithine rectrices are likely the result of an interplay between both sexual and naturally selective pressures, similar to the processes which produce analogous structures in birds today.

Plumadraco bankoorum. The skull of STM11−4.
(A) Photo of fossil specimen and (B) a corresponding line drawing. Well preserved bones are colored white, crushed or poorly preserved bones (or portions of bones) are grey, and preserved soft tissues are brown.

Abbreviations: at, atlas; cev, cervical vertebrae; dn, dentary; fe, feathers; fp, frontal process of the premaxilla; fe, feather; fr, frontal; l, left; mx, maxilla; ns, nasal; pmx, premaxilla; pr, parietal; r, right; su, surangular; to, tooth. 

Scale bar 10 mm.

Plumadraco bankoorum. Specimen STM11−4 
(A) The holotype specimen of Plumadraco, (B) a closer view of the body and, (C) a line drawing of the same portion of the body shown in B. Well preserved bones are colored white, crushed or poorly preserved bones (or portions of bones) are grey, and preserved soft tissues are brown. The extent of the feather traces are denoted by the thin black outline around the body. Potential outline or crural feather present along the cranial face of the tibia.

Abbreviations: al, alula; cev, cervical vertebrae; co, coracoid; fm, femur; fu, furcula; hu, humerus; il, ilium; is, ischium; ma, manus; ph, phalanges (of the peds); pu, pubis; py, pygostyle; ri, rib(s); ra, radius; sc, scapula; sk, skull; sp, sternal plate; sy, synsacrum; tb, tibia; tmt, tarsometatarsus; tf, tail feathers; tv, thoracic vertebrae; ul, ulna. 

Scale bar (A, C) equals 50 mm.

Systematic paleontology

Aves Linnaeus, 1758

Pygostylia Chiappe et al., 2002  

Ornithothoraces Chiappe, 1995 

Enantiornithes Walker, 1981

Plumadraco bankoorum gen. et sp. nov.

Holotype. STM11−4 is a complete, articulated specimen preserved in a single slab primarily in dorsal aspect with feathers preserved around the head, body, wings, and tail.

Locality and horizon. Near Xiaotaizi Village, Jianchang County, Liaoning Province, Jiufotang Formation, 121 Ma (Lower Aptian). 

Diagnosis: Mid-sized [112–144 g, similar to some extant turdids (e.g., Cochoa, Turdus) and meliphagids (e.g., Anthochaera) enantiornithine (ventral margin of the furcula wider than dorsal margin; acrocoracoid, glenoid, and scapular cotyla omal-sternally aligned; minor metacarpal extending distally farther than the major metacarpal; metatarsal IV thinner than metatarsals II and III with the trochlea reduced to a single condyle; and a J-shaped metatarsal I), belonging to the family Bohaiornithidae (basally robust, apically tapered dentition; unforked dentary- surangular articulation; proportional width of the coracoid’s sternal margin; caudolateral projection of the sternal plate’s lateral trabeculae; well-developed abruptly terminating deltopectoral crest; robust pedal unguals), with the unique combination of the following features: corpus of the premaxillae dorsoventrally deeper than the dentaries; rostral ~80% of the dentary with parallel dorsal and ventral margins; tip of dentary is rostrodorsally tapered; at least nine sacral vertebrae; caudally-oriented lateral trabeculae of the sternum with asymmetrical, fan-shaped distal expansions; phalanx I of the manual digit craniocaudally thin; weakly curved pedal unguals; RDFs approximately twice body length.

Etymology. “Pluma”, Latin for feather, and “draco”, Latin for dragon. In the theme of avian biology and evolution, the specific name, “bankoorum”, honors Winston E. and Paul C. Banko. Together, their momentous life-long efforts have significantly contributed to our understanding of avian biology and conservation, particularly across the Hawaiian archipelago. Plumadraco bankoorum, the Banko’s feather dragon.

 B) Finely-preserved structures present in the proximal portion of the right RDF of Plumadraco bankoorum, C) and the preserved racket showing the differentiated barbs and the reduction, and eventual complete termination, of the central support structures (i.e., ramus and medial stripe). (D) The unique, undifferentiated barbs of the occipital plumes of Pteridophora alberti (King-of-Saxony Bird-of-Paradise) (FMNH 280831) forming tab-like laminated sheets. These structures may be uniquely analogous to the lateral margins (ribbon-like sheets) of enantiornithine RDFs preceding the distal ornaments.
 (E) An in-life restoration of Plumadraco. Illustration by Ville Sinkkonen.

  Results of phylogenetic analyses suggest Plumadraco belongs to the diverse Bohaiornithidae.

 

 male and female Plumadraco bankoorum

Illustration: Ville Sinkkonen

 Alexander D. Clark, Jingmai K. O’Connor, Xiaoli Wang, Yan Wang, Stephen Pruett-Jones, Xiangyu Zhang, Xing Wang, Xiaoting Zheng and Zhonghe Zhou. 2026. Hyperelongate Ornamental Tail Feathers in A New early Cretaceous enantiornithine Bird. PLoS One 21(5): e0347641. DOI: doi.org/10.1371/journal.pone.0347641 [May 27, 2026]