INTRODUCTION

The dome-headed dinosaur from Mongolia is the oldest ever found. A fossil from about 108 million years ago reveals an early member of the pachycephalosaurs, a group of dinosaurs with protrusions on their skulls that may have been used in combat.

Palaeontologists working in the Dundgovi desert of Mongolia saw the fossil skull protruding from the rock like a cabochon jewel*, says Dr. Lindsay E. Zanno, Head of Palaeontology Division of the North Carolina Museum of Natural Sciences.  “Thus we chose the species name ‘rinpoche’, which means ‘precious one”.

Z. rinpoche predates any other pachycephalosaur species by around 15 million years and is also the most complete specimen ever found, with a near-complete skull and limb bones and substantial parts of its vertebrae and hips. The team also recovered hand bones, as well as stomach stones, which would have been used to grind its food.

The fossil dome is covered in dimples, which may indicate the presence of other, unknown features on its head. “Pachycephalosaur skulls are so flashy,” says Zanno. “They not only have domes, they also have bony spikes and nodes around the skull for display.  These ornaments were essentially dome accessories.”

To determine the age of the dinosaur at its death, the team cut a thin slice of its lower leg bone. They describe it as a “teenager” that would have been about a metre long and weighed just under 6 kilograms. Although it is impossible to estimate how big it would have been had it reached adulthood, other pachycephalosaurs reached lengths of more than 4 metres and 400 kilograms in weight.

“The tissue preserves two growth rings and indicates the animal was still actively growing at the time of its death,” says Zanno. “The bones of the spine are also unfused, leaving room to grow.”

CT scans of the dome show that its structure was fully formed, indicating that even as a juvenile, this feature was fully developed, highlighting its importance.

[Source: Edited extract of Dome-headed dinosaur from Mongolia is the Oldest Ever Found, an article by J. Woodford in NewScientist published 17 September 2025.]

___________________________

ACTUAL RESEARCH

Chinzorig, T., Takasaki, R., Yoshida, J. et al. A Domed Pachycephalosaur from the Early Cretaceous of Mongolia. Nature (2025). 

ABSTRACT

The dome-headed pachycephalosaurians are among the most enigmatic dinosaurs. Bearing a hypertrophied skull roof and elaborate cranial ornamentation, members of the clade are considered to have evolved complex sociosexual systems.

Despite their importance in understanding behavioural ecology in Dinosauria, the absence of uncontested early diverging taxa has hindered our ability to reconstruct the origin and early evolution of the clade. Here we describe Zavacephale* rinpoche gen. et sp. nov., from the Lower Cretaceous Khuren Dukh Formation* of Mongolia, the most skeletally complete and geologically oldest pachycephalosaurian discovered globally. Z. rinpoche exhibits a well-developed frontoparietal dome and preserves the clade’s first record of manual elements and gastroliths.

Phylogenetic analysis* recovered Z. rinpoche as one of the earliest diverging pachycephalosaurians, pushing back fossil evidence of the frontoparietal dome by at least 14 Myr* and clarifying macroevolutionary trends in its assembly. We found that the earliest stage of dome evolution occurred by means of a frontal-first developmental pattern with retention of open supratemporal fenestra, mirroring proposed ontogenetic trajectories in some Late Cretaceous taxa. Finally, intraskeletal osteohistology of the frontoparietal dome and hindlimb demonstrate decoupling of sociosexual and somatic maturity in early pachycephalosaurians, with advanced dome development preceding terminal body size.

_______________________

DATA AVAILABILTY

The Z. rinpoche holotype specimen* (MPC-D 100/1209) is reposited in the Institute of Paleontology, Mongolian Academy of Sciences on Peace Avenue in the Bayanzurkh District of the nation’s capital Ulaanbaatar. Geographic coordinate data are available upon request from the MPC-D for scientific purposes.

______________________

PREVIOUS SCIENTIFIC RESEARCH AND EVIDENCE ON WHICH THE ABOVE FINDINGS RE. Z. RINPOCHE ARE BASED

Sues, H.-D. Functional morphology of the dome in pachycephalosaurid dinosaurs. N. Jb. Geol. Palaontol. Mh. 8, 459–472 (1978).

Snively, E. & Theodor, J. M. Common functional correlates of head-strike behavior in the pachycephalosaur Stegoceras validum (Ornithischia, Dinosauria) and combative artiodactyls. PLoS ONE 6, e21422 (2011).

Peterson, J. E., Dischler, C. & Longrich, N. R. Distributions of cranial pathologies provide evidence for head-butting in dome-headed dinosaurs (Pachycephalosauridae). PLoS ONE 8, e68620 (2013).

Evans, D. C., Schott, R. K., Larson, D. W., Brown, C. M. & Ryan, M. J. The oldest North American pachycephalosaurid and the hidden diversity of small-bodied ornithischian dinosaurs. Nat. Commun. 4, 1828 (2013).

Dyer, A. D., Powers, M. J. & Currie, P. J. Problematic putative pachycephalosaurids: synchrotron µCT imaging shines new light on the anatomy and taxonomic validity of Gravitholus albertae from the Belly River Group (Campanian) of Alberta, Canada. Vertebr. Anat. Morphol. Palaeontol. 10, 65–110 (2023).

Horner, J. R., Goodwin, M. B. & Evans, D. C. A new pachycephalosaurid from the Hell Creek Formation, Garfield County, Montana, U.S.A. J. Vertebr. Paleontol. 42, e2190369 (2023).

Woodruff, D. C., Schott, R. K. & Evans, D. C. Two new species of small-bodied pachycephalosaurine (Dinosauria, Marginocephalia) from the uppermost Cretaceous of North America suggest hidden diversity in well-sampled formations. Pap. Palaeontol. 9, e1535 (2023).

Knapp, A., Knell, R. J. & Hone, D. W. E. Three-dimensional geometric morphometric analysis of the skull of Protoceratops andrewsi supports a socio-sexual signaling role for the ceratopsian frill. Proc. R. Soc. B 288, 20202938 (2021).

Main, R. P., De Ricqlès, A., Horner, J. R. & Padian, K. The evolution and function of thyreophoran dinosaur scutes: implications for plate function in stegosaurs. Paleobiology 31, 291–314 (2005).

Arbour, V. M., Zanno, L. E. & Evans, D. C. Palaeopathological evidence for intraspecific combat in ankylosaurid dinosaurs. Biol. Lett. 18, 20220404 (2022).

Brown, C. M., Campione, N. E., Mantilla, G. P. W. & Evans, D. C. Size-driven preservational and macroecological biases in the latest Maastrichtian terrestrial vertebrate assemblages of North America. Paleobiology 48, 210–238 (2022).

Hayashi, S., Carpenter, K., Watabe, M. & McWhinney, L. A. Ontogenetic histology of Stegosaurus plates and spikes. Palaeontology 55, 145–161 (2012).

Butler, R. J. & Zhao, Q. The small-bodied ornithischian dinosaurs Micropachycephalosaurus hongtuyanensis and Wannanosaurus yansiensis from the Late Cretaceous of China. Cretaceous Res. 30, 63–77 (2009).

Schott, R. K. et al. Cranial ontogeny in Stegoceras validum (Dinosauria: Pachycephalosauria): a quantitative model of pachycephalosaur dome growth and variation. PLoS ONE 6, e21092 (2011).

Campione, N. E., Evans, D. C., Brown, C. M., Carrano, M. T. & Revell, L. Body mass estimation in non-avian bipeds using a theoretical conversion to quadruped stylopodial proportions. Methods Ecol. Evol. 5, 913–923 (2014).

Ito, M., Matsukawa, M., Saito, T. & Nichols, D. J. Facies architecture and paleohydrology of a synrift succession in the Early Cretaceous Choyr Basin, southeastern Mongolia. Cretaceous Res. 27, 226–240 (2006).

Jerzykiewicz, T. & Russell, D. A. Late Mesozoic stratigraphy, and vertebrates of the Gobi Basin. Cretaceous Res. 12, 345–377 (1991).

Nichols, D. J., Matsukawa, M. & Ito, M. Palynology and age of some Cretaceous nonmarine deposits in Mongolia and China. Cretaceous Res. 27, 241–251 (2006).

Maryańska, T. & Osmólska, H. Pachycephalosauria, a new suborder of ornithischian dinosaurs. Acta Palaeontol. Pol. 30, 45–102 (1974).

Perle, A., Maryańska, T. & Osmólska, H. Goyocephale lattimorei gen. et sp. n., a new flat-headed pachycephalosaur (Ornithischia, Dinosauria) from the Upper Cretaceous of Mongolia. Acta Palaeontol. Pol. 27, 115–132 (1982).

Gilmore, C. W. On Troodon validus, an orthopodous dinosaur from the Belly River Cretaceous of Alberta, Canada. Alberta Univ. Bull. 1, 1–43 (1924).

Woodruff, D. C., Goodwin, M. B., Lyson, T. R. & Evans, D. C. Ontogeny and variation of the pachycephalosaurine dinosaur Sphaerotholus buchholtzae, and its systematics within the genus. Zool. J. Linn. Soc. 193, 563–601 (2021).

Brown, B. & Schlaikjer, E. M. A study of the troodont dinosaurs with the description of a new genus and four new species. Bull. Am. Mus. Nat. Hist. 82, 115–150 (1943).

Sullivan, R. M. A taxonomic review of the Pachycephalosauridae (Dinosauria: Ornithischia). Bull. New Mexico Mus. Nat. Hist. Sci. 35, 347–365 (2006).

Williamson, T. E. & Carr, T. D. A new genus of derived pachycephalosaurian from western North America. J. Vertebr. Paleontol. 22, 779–801 (2002).

Schott, R. K. & Evans, D. C. Squamosal ontogeny and variation in the pachycephalosaurian dinosaur Stegoceras validum Lambe, 1902, from the Dinosaur Park Formation, Alberta. J. Vertebr. Paleontol. 32, 903–913 (2012).

Schott, R. K. & Evans, D. C. Cranial variation and systematics of Foraminacephale brevis gen. nov. and the diversity of pachycephalosaurid dinosaurs (Ornithischia: Cerapoda) in the Belly River Group of Alberta, Canada. Zool. J. Linn. Soc. 179, 865–906 (2016).

Sullivan, R. M. Revision of the dinosaur Stegoceras Lambe (Ornithischia, Pachycephalosauridae). J. Vertebr. Paleontol. 23, 181–207 (2003).

Han, F.-L., Forster, C. A., Clark, J. M. & Xu, X. Cranial anatomy of Yinlong downsi (Ornithischia: Ceratopsia) from the Upper Jurassic Shishugou Formation of Xinjiang, China. J. Vertebr. Paleontol. 36, e1029579 (2015).

Evans, D. C., Brown, C. M., You, H. & Campione, N. E. Description and revised diagnosis of Asia’s first recorded pachycephalosaurid, Sinocephale bexelli gen. nov., from the Upper Cretaceous of Inner Mongolia, China. Can. J. Earth Sci. 58, 981–992 (2021).

Goodwin, M. B. & Horner, J. R. Cranial histology of pachycephalosaurs (Ornithischia: Marginocephalia) reveals transitory structures inconsistent with head-butting behavior. Paleobiology 30, 253–267 (2004).

Evans, D. C. et al. Morphology and histology of new cranial specimens of Pachycephalosauridae (Dinosauria: Ornithischia) from the Nemegt Formation, Mongolia. Palaeogeogr. Palaeoclimatol. Palaeoecol. 494, 121–134 (2018).

Hou, L. A new primitive Pachycephalosauria from Anhui, China. Vertebrata PalAsiatica 15, 198–202 (1977).

Owen, R. Monograph on the Fossil Reptilia of the Wealden and Purbeck Formations. Part V. Lacertilia. Palaeontogr. Soc. Monogr. 12, 31–39 (1861).

Thulborn, R. A. A new heterodontosaurid dinosaur (Reptilia: Ornithischia) from the Upper Triassic Red Beds of Lesotho. Zool. J. Linn. Soc. 55, 151–175 (1974).

Sues, H.-D. & Galton, P. M. Anatomy and classification of the North American Pachycephalosauria (Dinosauria: Ornithischia). Palaeontographica 198, 1–40 (1987).

Brown, C. M. & Russell, A. P. Homology and architecture of the caudal basket of Pachycephalosauria (Dinosauria: Ornithischia): the first occurrence of myorhabdoi in Tetrapoda. PLoS ONE 7, e30212 (2012).

Han, F., Forster, C. A., Xu, X. & Clark, J. M. Postcranial anatomy of Yinlong downsi (Dinosauria: Ceratopsia) from the Upper Jurassic Shishugou Formation of China and the phylogeny of basal ornithischians. J. Syst. Palaeontol. 16, 1159–1187 (2006).

Wings, O. & Sander, P. M. No gastric mill in sauropod dinosaurs: new evidence from analysis of gastrolith mass and function in ostriches. Proc. R. Soc. B: Biol. Sci. 274, 635–640 (2007).

Takasaki, R. & Kobayashi, Y. Effects of diet and gizzard muscularity on grit use in domestic chickens. PeerJ 8, e10277 (2020).

Takasaki, R. Herbivorous Adaptations of Dinosauria: Hadrosaurid Foraging Strategy and Archosaur Gastroliths. PhD thesis, Hokkaido Univ. (2019).

Horner, J. R. & Goodwin, M. B. Extreme cranial ontogeny in the Upper Cretaceous dinosaur Pachycephalosaurus. PLoS ONE 4, e7626 (2009).

Goodwin, M. B., Buchholtz, E. A. & Johnson, R. E. Cranial anatomy and diagnosis of Stygimoloch spinifer (Ornithischia: Pachycephalosauria) with comments on cranial display structures in agonistic behavior. J. Vertebr. Paleontol. 18, 363–375 (1998).

De Margerie, E., Cubo, J. & Castanet, J. Bone typology and growth rate: testing and quantifying ‘Amprino’s rule’ in the mallard (Anas platyrhynchos). C.R. Biol. 325, 221–230 (2002).

Goodwin, M. B. & Evans, D. C. The early expression of squamosal horns and parietal ornamentation confirmed by new end-stage juvenile Pachycephalosaurus fossils from the Upper Cretaceous Hell Creek Formation, Montana. J. Vertebr. Paleontol. 36, 1–8 (2016).

Prondvai, E. et al. Radial porosity profiles: a new bone histological method for comparative developmental analysis of diametric limb bone growth. R. Soc. Open Sci. 9, 211893 (2022).

Griffin, C. T. et al. Assessing ontogenetic maturity in extinct saurian reptiles. Biol. Rev. 96, 470–525 (2021).

Knell, R. J., Naish, D., Tomkins, J. L. & Hone, D. W. Sexual selection in prehistoric animals: detection and implications. Trends Ecol. Evol. 28, 38–47 (2013).

Erickson, G. M., Curry, R. K., Varricchio, D. J., Norell, M. A. & Xu, X. Growth patterns in brooding dinosaurs reveals the timing of sexual maturity in non-avian dinosaurs and genesis of the avian condition. Biol. Lett. 3, 558–561 (2007).

Andrew, H., Lee, A. H. & Werning, S. Sexual maturity in growing dinosaurs does not fit reptilian growth models. Proc. Natl Acad. Sci. USA 105, 582–587 (2008).

Prondvai, E., Godefroit, P., Adriaens, D. & Hu, D. Intraskeletal histovariability, allometric growth patterns, and their functional implications in bird-like dinosaurs. Sci. Rep. 8, 258 (2018).

Cullen, T. M., Simon, D. J., Benner, E. K. & Evans, D. C. Morphology and osteohistology of a large-bodied caenagnathid (Theropoda, Oviraptorosauria) from the Hell Creek Formation (Montana): implications for size-based classifications and growth reconstruction in theropods. Pap. Palaeontol. 7, 751–767 (2021).

Monfroy, Q. T. & Kundrát, M. The osteohistological variability in the evolution of basal avialans. Acta Zool. 103, 1–28 (2022).

Wick, S. L. & Lehman, T. M. A rare ‘flat-headed’ pachycephalosaur (Dinosauria: Pachycephalosauridae) from West Texas, USA, with morphometric and heterochronic considerations. Geobios 86, 89–106 (2024).

Nirody, J. A. et al. Quantifying vascularity in the frontoparietal dome of Stegoceras validum (Dinosauria: Pachycephalosauridae) from high-resolution CT scans. J. Vertebr. Paleontol. 41, e2036991 (2021).

Fonseca, A. O. et al. A comprehensive phylogenetic analysis on early ornithischian evolution. J. Syst. Palaeontol. 22, 2346577 (2024).

Sereno, P. C. in The Age of Dinosaurs in Russia and Mongolia (eds Benton, M. J. et al.) 480–516 (Cambridge Univ. Press, 2000).

Huang, L.-K. & Wang, M.-J. J. Image thresholding by minimizing the measures of fuzziness. Pattern Recognit. 28, 41–51 (1995).

Madzia, et al. The phylogenetic nomenclature of ornithischian dinosaurs. PeerJ 9, e12362 (2021).

Lamm, E. T. in Bone Histology of Fossil Tetrapods (eds Padian, K. & Lamm, E. T.) 55–160 (California Univ. Press, 2013)

Xu, X., Forster, C. A., Clark, J. M. & Mo, J. A basal ceratopsian with transitional features from the Late Jurassic of northwestern China. Proc. Biol. Sci. 273, 2135–2140 (2006).

Osi, A., Prondvai, E., Butler, R. & Weishampel, D. B. Phylogeny, histology and inferred body size evolution in a new rhabdodontid dinosaur from the Late Cretaceous of Hungary. PLoS ONE 7, e44318 (2012).

Boyd, C. A. The systematic relationships and biogeographic history of ornithischian dinosaurs. PeerJ 3, e1523 (2015).

Dieudonné, P. E., Cruzado-Caballero, P., Godefroit, P. & Tortosa, T. A new phylogeny of cerapodan dinosaurs. Hist. Biol. 33, 2335–2355 (2020).

Ohashi, T. & Barrett, P. M. A new ornithischian dinosaur from the Lower Cretaceous Kuwajima Formation of Japan. J. Vertebr. Paleontol. 29, 748–757 (2009).

Butler, R. J., Upchurch, P. & Norman, D. B. The phylogeny of the ornithischian dinosaurs. J. Syst. Palaeontol. 6, 1–40 (2008).

Longrich, N. R., Sankey, J. & Tanke, D. Texacephale langstoni, a new genus of pachycephalosaurid (Dinosauria: Ornithischia) from the upper Campanian Aguja Formation, southern Texas, USA. Cretaceous Res. 31, 274–284 (2010).

Hill, R. V., Witmer, L. M. & Norell, M. A. A new specimen of Pinacosaurus grangeri (Dinosauria: Ornithischia) from the Late Cretaceous of Mongolia: ontogeny and phylogeny of ankylosaurs. Am. Mus. Novit. 3395, 1–29 (2003).

Han, F., Forster, C. A., Clark, J. M. & Xu, X. A new taxon of basal ceratopsian from China and the early evolution of Ceratopsia. PLoS ONE 10, e0148689 (2015).

Makovicky, P. J. & Norell, M. A. Yamaceratops dorngobiensis, a new primitive ceratopsian (Dinosauria: Ornithischia) from the Cretaceous of Mongolia. Am. Mus. Novit. 3530, 1–42 (2006).

Goloboff, P. A. & Catalano, S. A. TNT version 1.5, including a full implementation of phylogenetic morphometrics. Cladistics 32, 221–238 (2016).

Ronquist, F. & Huelsenbeck, J. P. MrBayes 3: Bayesian phylogenetic inference under mixed models. Bioinformatics 19, 1572–1574 (2003).

Goloboff, P. A. Extended implied weighting. Cladistics 30, 260–272 (2014).

Diego, P. & Goloboff, P. A. The impact of unstable taxa in coelurosaurian phylogeny and resampling support measures for parsimony analyses. Bull. Am. Mus. Nat. Hist. 440, 97–115 (2020).

Brusatte, S. L., Benton, M. J., Ruta, M. & Lloyd, G. T. Superiority, competition, and opportunism in the evolutionary radiation of dinosaurs. Science 321, 1485–1488 (2008).

Bapst, D. W. paleotree: an R package for paleontological and phylogenetic analyses of evolution. Methods Ecol. Evol. 3, 803–807 (2012).

Bell, M. A., Lloyd, G. T. & Smith, A. strap: an R package for plotting phylogenies against stratigraphy and assessing their stratigraphic congruence. Palaeontology 58, 379–389 (2015).

Zhang, C., Stadler, T., Klopfstein, S., Heath, T. A. & Ronquist, F. Total-evidence dating under the fossilized birth–death process. Syst. Biol. 65, 228–249 (2016).

Kikins, R., Pieper, S. & Vosburgh, K. G. in Intraoperative Imaging and Image-Guided Therapy (ed. Jolesz, F.) 277–289 (Springer, 2014).

Schneider, C. A., Rasband, W. S. & Eliceiri, K. W. NIH Image to ImageJ: 25 years of image analysis. Nat. Methods 9, 671–675 (2012).

Williamson, T. E. & Brusatte, S. L. Pachycephalosaurs (Dinosauria: Ornithischia) from the Upper Cretaceous (upper Campanian) of New Mexico: a reassessment of St. validum novomexicanum. Cretaceous Res. 62, 29–43 (2016).

Julie, J. & Francois, H. missMDA: a package for handling missing values in multivariate data analysis. J. Stat. Softw. 70, 1–31 (2016).

Warton, D. I., Duursma, R. A., Falster, D. S. & Taskinen, S. smatr 3—an R package for estimation and inference about allometric lines. Methods Ecol. Evol. 3, 257–259 (2012).

Elliott, N. G., Haskard, K. & Koslow, J. A. Morphometric analysis of orange roughly (Hoplostethus atlanticus) off the continental slope of southern Australia. J. Fish Biol. 46, 202–220 (1995).

Mannion, P. D. & Upchurch, P. Completeness metrics and the quality of the sauropodomorph fossil record through geological and historical time. Paleobiology 36, 283–302 (2010).

Chinzorig, T. et al. Figshare https://doi.org/10.6084/m9.figshare.28509500 (2025).

________________________

ACKNOWLEDGEMENTS

[The researchers] thank the field crew and local and regional Mongolian authorities (Ministry of Education, Culture, Science, and Sports and local governor offices of the Dundgovi Province) for fieldwork assistance and permissions.

We thank preparators C. Bayardorj (MPC-D), A. Giterman (NCSM) and B. Byambatsogt (MPC-D) for fossil preparation and reproduction.

We thank the following people and institutions: C. Mehling; R. Benson (AMNH); J. Mallon; S. Rufolo (CMN); D. Evans, K. Seymour (ROM) and P. Currie (UoA) for collections access; H. Avrahami and L. Herzog (NCSM) for computed tomography scanning and other laboratory support; D. Idersaikhan (MPC-D), T. Tanaka (Univ. of Hyogo), S. Hayashi (OUS) and M. Iijima (IVPP) for extra photographs; G. Masukawa for skeletal reconstruction; M. Hattori for life reconstruction artwork; and K. Chiba (OUS), D. Evans (ROM), C. Woodruff (Patricia & Phillip Frost Art Museum), A. Dyer (ROM) and J. Mallon (CMN) for discussion.

The Willi Hennig Society provided free TNT software for phylogenetic analyses.

This study was supported by a Grant-in-Aid for JSPS Research Fellow of Japan (17J06410 and 20J01696) and JSPS Overseas Research Fellowships to R.T.; JSPS KAKENHI Grant (21K14026) to J.Y.; a National Geographic Society grant (NGS-100601R-23) to L.E.Z., R.T.T., K.T., J.Y. and T.C.; and a Paleontological Society Arthur J. Boucot Research Award and Collection Study Grant of the RGGS at the AMNH to T.C.

________________________

AUTHORS and AFFILIATIONS

Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA. Tsogtbaatar Chinzorig & Lindsay E. Zanno

Institute of Paleontology, Mongolian Academy of Sciences, Ulaanbaatar, Mongolia
Tsogtbaatar Chinzorig, Batsaikhan Buyantegsh, Buuvei Mainbayar & Khishigjav Tsogtbaatar

Paleontology, North Carolina Museum of Natural Sciences, Raleigh, NC, USA
Tsogtbaatar Chinzorig, Ryan T. Tucker & Lindsay E. Zanno

Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada. Ryuji Takasaki

Faculty of Biosphere-Geosphere Science, Okayama University of Science, Okayama, Japan. Ryuji Takasaki

Fukushima Museum, Aizu Wakamatsu City, Fukushima, Japan. Junki Yoshida

Department of Earth Sciences, Stellenbosch University, Stellenbosch, South Africa.
Ryan T. Tucker & Lindsay E. Zanno

Department of Geology, Field Museum of Natural History, Chicago, IL, USA. Lindsay E. Zanno

Natural History Museum of Utah, University of Utah, Salt Lake City, UT, USA. Lindsay E. Zanno

Vertebrate Paleontology, Oklahoma Museum of Natural History, Norman, OK, USA. Lindsay E. Zanno

Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa. Lindsay E. Zanno

_________________________

To read the full version of the 2025 research paper, see: DOI: 10.1038/s41586-025-09213-6.

_________________________

*CP notes (language)

• Cabochon refers to a gem that has been polished but not faceted.
• In Paleontology and related sciences, Myr is an abbreviation for Million years or Million years ago, used to denote a unit of time equal to 1,000,000 years, though alternatives like Ma and Mya are also common.
• Cephale (or Kephalē, Κεφαλή) is the Ancient Greek word for “head”.
• The Lower Cretaceous Khuren Dukh Formation, also known as the Khukhteeg Formation is a geological formation dating to the Aptian-Albian stages of the Early Cretaceous (roughly 125-100 million years ago) where fossilised evidence of dinosaurs, reptiles, plants and angiosperms have been noted. The formation is found in central and southeastern Mongolia particularly in the Choir Basin.
• Phylogenetic analysis is a method for estimating and visually representing the evolutionary relationships between genes, populations, or species using data like DNA or protein sequences, morphological traits o behaviours. It results in a branching digram called a phylogenetic tree, which illustrates how different organisms re connected through a shared evolutionary history, helping scientists understand biodiversity and evolution.
• A holotype specimen is a single, specific physical example of an organism that was formally designated by scientists when a new species was first described and named. Zavacephale rinpoche (Z.rinpoche) now serves as the authoritative, name-bearing reference for this new species which all scientist must now compare their findings to, ensuring consistency and stability in subsequent scientific classification.
• And finally, if you are interested in paleontology (the branch of science concerned with fossil animals and plants), many of the above previously published research papers are available to read in the public domain using Google Scholar and/or PubMed.

End of transcript.

Refer to the INDEX for other articles that may be of interest.

© 2013-2025. CP in Mongolia. This post is licensed under the  Creative Commons Attribution 4.0 International License. Documents linked from this page may be subject to other restrictions.  Posted: 19 September 2025. Last updated: 19 September 2025.