[Paleontology • 2026] Doolysaurus huhmini • A New Dinosaur Species from Korea and its implications for early-diverging neornithischian diversity

 Doolysaurus huhmini

Jung, Kim, Jo & Clarke, 2026

DOI: doi.org/10.3897/fr.29.178152 

Abstract

The Korean dinosaur fossil record is exceptionally rich in trackways and eggs, yet skeletal remains are exceedingly rare. Two species have been described based on postcranial elements, and a taxon known from cranial materials has not yet been reported. Here, we report a new early-diverging neornithischian species, known from a small, partially articulated skeleton comprising cranial and postcranial elements as well as gastroliths. The specimen is from the mid-Cretaceous Ilseongsan Formation of Aphae Island (Aphaedo). X-ray micro-computed tomography (micro-CT) revealed the anatomy of the new species, including the first studied cranial remains of a dinosaur from Korea. The size and anatomical features of the specimen, along with histological analysis, indicate that it is not a fully grown individual, probably 0–2 years old. Gastroliths are present, with morphologies and a relative mass proposed to be consistent with a more omnivorous diet. Phylogenetic analyses recover the new species, Doolysaurus huhmini gen. et sp. nov., as a thescelosaurid. The recovery of Doolysaurus with most other Asian thescelosaurids near the base of this clade provides further evidence for its origin and early biogeography. The new discovery suggests that other small dinosaur fossils may be found at Aphaedo or at sites with similar taphonomic conditions in Korea; Doolysaurus is consistent with richer dinosaurian diversity in the Cretaceous of Korea than is represented in its rich trace fossil record.

Key Words: Aphaedo, Doolysaurus huhmini, mid-Cretaceous, Neornithischia, Thescelosauridae, Shinan

Skeletal anatomy of Doolysaurus huhmini gen. et sp. nov.

All scale bars are 10 mm. Artwork by Janet Cañamar.

Abbreviations: 4th tr: fourth trochanter; be: buccal emargination; boc: basioccipital condyle; bpro: boss for articulation with proatlas; bt: basal tubera; cc: cnemial condyle; cfo: carotid aorta foramen; cpc: coronoid process; dh: dorsal head; dtt: dentary tooth; ec: endocranial cavity; eoas: exoccipital articular surface; fm: foramen magnum; lc: lateral condyle; lw: lateral wing; mc: medial condyle; mkc: Meckelian canal; mt: metatarsal; mw: medial wing; mxt: maxillary tooth; ns: neural spine; oc: occipital condyle; pd: pedal digit; plp: posterolateral process; pop: paroccipital process; poz: postzygapophysis; prz: prezygapophyses; pscf: posterior semicircular canal foramen; ptf: posttemporal foramen.

An artist’s interpretation of a juvenile Doolysaurus huhmini gen. et sp. nov.
 It is depicted alongside birds and other dinosaurs that lived during the Cretaceous in what is now South Korea.

Artwork by Jun Seong Yi.

 Doolysaurus huhmini gen. et sp.

Diagnosis. Doolysaurus huhmini is a small-bodied, early-diverging neornithischian dinosaur with the following unique combination of features recovered from analysis of the Fonseca et al. (2024) dataset, including one optimized autapomorphy (*): (1) the lateral condyle of the quadrate is larger than the medial condyle (shared with Orodromeus and Haya) (ch.196:2); (2) Exoccipital, relative positions of the exits of the hypoglossal nerve (XII) combined into a single exit (shared with Jeholosaurus) (ch. 254:2); (3) Basioccipital, contribution to the border of the foramen magnum more than 1/3 its basioccipital condyle size (shared with Fona) (ch. 261: 0); (4) the apex of the maxillary teeth is located posterior to the center (shared with ...

Etymology. The generic name Doolysaurus honors “Dooly the Little Dinosaur,” an iconic Korean cartoon baby dinosaur character created by Soo-Jung Kim in 1983; saurus is from the Greek σαῦρος (sauros), meaning “lizard.” The specific name, huhmini, honors Professor Dr. Min Huh, a paleontologist who conducted research on a theropod fossil nest from the Aphaedo site, in recognition of his outstanding contributions to the study of dinosaurs in Korea over the past 30 years.

 Jongyun Jung, Minguk Kim, Hyemin Jo and Julia A. Clarke. 2026. A New Dinosaur Species from Korea and its implications for early-diverging neornithischian diversity. Fossil Record 29(1): 87-113. DOI: doi.org/10.3897/fr.29.178152 

https://blog.pensoft.net/2026/03/19/fossil-x-ray-reveals-new-species-of-baby-dino-named-after-iconic-korean-cartoon

[Paleontology • 2025] Pulaosaurus qinglong • A New neornithischian Dinosaur from the Upper Jurassic Tiaojishan Formation of northern China

Pulaosaurus qinglong

 Yang, King & Xu, 2025

  

DOI: doi.org/10.7717/peerj.19664

Abstract

The Middle and Late Jurassic Yanliao Biota is different from other contemporaneous fossil assemblages in that it lacks neornithischian dinosaurs. Here, we report a new, early-diverging neornithischian, Pulaosaurus qinglong gen. et sp. nov., from the Upper Jurassic Tiaojishan Formation of Qinglong, Hebei Province, of northern China. Diagnostic or noteworthy morphological characteristics of P. qinglong include: five premaxillary teeth; a small boss is present on the caudoventral corner of the dorsal ramus of the jugal; a nuchal crest is located along the parietal; the manus has five digits; a supra-acetabular crest is present on the ilium; the paired arytenoids are gracile and leaf-like in form; the obturator process along the ischium is located near the pubic peduncle; a notch-like shaped obturator opening is present within the pubis; a robust fibular condyle forms a dorsoventrally extending crest on the tibia; a subtriangular flange on the anterior surface of the astragalus extends dorsolaterally along three distal tarsals; three of the distal tarsals are unfused, including a small drop-shaped distal tarsal 3; distal tarsal 3 is pierced by a foramen. A phylogenetic analysis places P. qinglong as one of the earliest-diverging neornithischians yet described. Moreover, P. qinglong represents the second known dinosaur to preserve ossified laryngeal elements, thus suggesting that a bird-like vocalization evolved early in non-avian dinosaur evolution.

The photograph of the whole skeleton of Pulaosaurus qinglong in left lateral view (IVPP V30936).

Dinosauria Owen, 1842

Ornithischia Seeley, 1887

Neornithischia Cooper, 1985

Pulaosaurus qinglong gen. et sp. nov.

Etymology: The generic name is derived from Chinese Pinyin for “Pulao”, a mythical creature resembling the Chinese dragon. According to Chinese legends, the “Pulao” engages in loud shouting, thus referencing the possible bird-like vocalizations of this species. The specific name is derived from the Chinese Pinyin for “Qinglong”, which is the name of the county in Province Hebei, China, where the specimen was found.

 

Locality and horizon: Southern Shimen Gou, County Qinglong, Province Hebei, People’s Republic of China. Tiaojishan Formation, Callovian-Oxfordian (Middle-Upper Jurassic).

Diagnosis: A small-bodied neornthischian dinosaur characterized by the combination of the following characteristics (autapomorphies preceded by an asterisk): five premaxillary teeth; a small boss is located on the caudoventral corner of the dorsal ramus of the jugal; a nuchal crest that is located on the parietal the mani have five digits; a supra-acetabular crest is located on the ilium; a pair of gracile, leaf-like arytenoids are present; the obturator process is near the pubic peduncle; the opening of the obturator on the pubis is notch-shaped; *a robust fibular condyle forms a dorsoventrally extending crest on the tibia; a subtriangular flange extends dorsolaterally on four distal tarsals; *three distal tarsals are unfused with distal tarsal three that is drop-shaped; distal tarsal three is pierced by a foramen.  

...

Conclusions: 

Pulaosaurus qinglong gen. et sp. nov. is an early-diverging neornithischian species found in the Upper Jurassic Tiaojishan Formation of Province Hebei, China. A phylogenetic analysis places Pulaosaurus at the base of Neornithischia close to Agilisaurus, which is the earliest-diverging neornithischian. Pulaosaurus represents the first neornithischian found in the Yanliao Biota, and helps to fill the temporal and geographical gap in the distribution of Neornithischia within China. A pair of arytenoids are preserved in the Pulaosaurus holotype and represents the second case of an ossified laryngeal apparatus among non-avian dinosaurs. The arytenoids of Pulaosaurus indicates that ossified laryngeal apparatuses were present in Neornithischia, thus suggesting that the ossified laryngeal apparatus could be widespread across Dinosauria. As the morphology of Pulaosaurus arytenoids resembles the arytenoids of extant birds, it is possible for Pulaosaurus to have an avian-like vocalization.

Yunfeng Yang, James L. King and Xing Xu. 2025. A New neornithischian Dinosaur from the Upper Jurassic Tiaojishan Formation of northern China. PeerJ. 13:e19664 DOI: doi.org/10.7717/peerj.19664 [July 11, 2025]

[Paleontology • 2025] Enigmacursor mollyborthwickae • A neornithischian Dinosaur from the Upper Jurassic Morrison Formation of the western USA

Enigmacursor mollyborthwickae

Maidment & Barrett, 2025

 

DOI: doi.org/10.1098/rsos.242195

Artwork by Bob Nicholls.

Abstract

Although their remains have been known since the 1870s, the small, bipedal ornithischian dinosaurs from the Upper Jurassic Morrison Formation of the western USA remain poorly known. The historic type specimens are incomplete and poorly preserved and have recently been designated as nomina dubia. Here, we describe a recently collected, partial but three-dimensionally preserved skeleton of a new small-bodied ornithischian from the Morrison Formation of Colorado, USA, that we name Enigmacursor mollyborthwickae gen. et sp. nov. The skeleton includes substantial portions of the axial and appendicular skeleton and, when scored into a phylogenetic analysis, is shown to be a non-cerapodan neornithischian, whose closest relative is Yandusaurus hongheensis from the Late Jurassic of China. The discovery of Enigmacursor enhances the diversity of ornithischian dinosaurs from the Morrison Formation and provides new information on their anatomy. In addition, it demonstrates that there is additional cryptic diversity of small-bodied Morrison Formation ornithischians, suggesting they were a more diverse component of these Late Jurassic ecosystems than was previously realized.

Systematic palaeontology

Dinosauria (Owen 1842)

Ornithischia (Seeley 1888)

Neornithischia (Cooper 1985)

Enigmacursor mollyborthwickae gen. et sp. nov.

Holotype—NHMUK PV R 39000, a partial skeleton that includes three teeth, three cervical, 11 dorsal, two dorsosacral and five caudal vertebrae, 10 dorsal ribs, five chevrons, right sternum, both scapulae, both humeri, both radii, both ulnae, three metacarpals, left ilium, right ischium, right pubis, both femora, both tibiae, both fibulae, right astragalus and both pedes.

Diagnosis—Enigmacursor mollyborthwickae differs from all other ornithischian dinosaurs in possessing the following unique combination of features and one potential autapomorphy (the latter marked with an asterisk): (1) posterior articular facets offset ventrally relative to anterior articular facets on proximal dorsal vertebrae*; (2) absence of a supracetabular crest on the ilium; (3) femoral head separated from the greater trochanter by a trochanteric fossa; (4) apex of anterior trochanter situated level with the ventral margin of the femoral head; (5) absence of a ligament sulcus on the posterior surface of the femoral head; (6) ventral surface of fourth trochanter straight or slightly convex in medial or posterior view; (7) medially directed, hook-like posterior condyle of the proximal end of the tibia.

Etymology—Enigma, meaning a puzzle or mystery, in reference to the convoluted taxonomic history of small-bodied ornithischians from the Morrison Formation; cursor, from the Latin for ‘runner’, in reference to the cursorial morphology of the elongated hind limb and pes. The species name honours Molly Borthwick, whose generous donation allowed the NHMUK to acquire the specimen.

Enigmacursor mollyborthwickae
a) Skeletal reconstruction of with preserved elements shaded.
b) Life reconstruction. Artwork by Bob Nicholls.

Susannah C. R. Maidment and Paul M. Barrett. 2025. Enigmacursor mollyborthwickae, a neornithischian dinosaur from the Upper Jurassic Morrison Formation of the western USA. R. Soc. Open Sci. 12: 242195. DOI: doi.org/10.1098/rsos.242195 [25 June 2025]

https://www.nhm.ac.uk/discover/news/2025/june/new-species-mystery-dinosaur-unveiled-natural-history-museum.html

   

[Paleontology • 2024] Fona herzogae • A New semi-fossorial thescelosaurine Dinosaur (Neornithischia: Thescelosauridae) from the Cenomanian-age Mussentuchit Member of the Cedar Mountain Formation, Utah

Fona herzogae

Avrahami, Makovicky, Tucker & Zanno, 2024

 

DOI: 10.1002/ar.25505

Abstract

Thescelosaurines are a group of early diverging, ornithischian dinosaurs notable for their conservative bauplans and mosaic of primitive features. Although abundant within the latest Cretaceous ecosystems of North America, their record is poor to absent in earlier assemblages, leaving a large gap in our understanding of their evolution, origins, and ecological roles. Here we report a new small bodied thescelosaurine—Fona herzogae gen. et sp. nov.—from the Mussentuchit Member of the Cedar Mountain Formation, Utah, USA. Fona herzogae is represented by multiple individuals, representing one of the most comprehensive skeletal assemblages of a small bodied, early diverging ornithischian described from North America to date. Phylogenetic analysis recovers Fona as the earliest member of Thescelosaurinae, minimally containing Oryctodromeus, and all three species of Thescelosaurus, revealing the clade was well-established in North America by as early as the Cenomanian, and distinct from, yet continental cohabitants with, their sister clade, Orodrominae. To date, orodromines and thescelosaurines have not been found together within a single North American ecosystem, suggesting different habitat preferences or competitive exclusion. Osteological observations reveal extensive intraspecific variation across cranial and postcranial elements, and a number of anatomical similarities with Oryctodromeus, suggesting a shared semi-fossorial lifestyle.

SYSTEMATIC PALEONTOLOGY

DINOSAURIA Owen (1842).

ORNITHISCHIA Seeley (1887).

NEORNITHISCHIA Cooper, 1985 (sensu Butler et al., 2008).

ORNITHOPODA Marsh, 1881 (sensu Butler et al., 2008).

THESCELOSAURIDAE (Sternberg, 1937). 

THESCELOSAURINAE (Sternberg, 1940).

THESCELOSAURINAE indet.

Fona herzogae sp. nov.

  Holotype: NCSM 33548, a single partially articulated, nearly complete skeleton. 

 Occurrence: NCSM 33548 was recovered from the Karmic Orodromine locality (UT-16-07-22-Z1), lower Mussentuchit Member, upper Cedar Mountain Formation, Emery County, Utah, USA (Figure 1). Stratigraphic occurrence is between MAZ1 and Last Chance Sandstone (99.466 + 0.046/−0.053 Ma; Tucker et al., 2023) making it the only locality definitively preserving F. herzogae from the lower Mussentuchit unit to date. Mini Troll (NCPALEOUT16) is the geologically youngest locality, emplaced below MAZ3, with an age of 99.231 + 0.090/−0.052 Ma. FMNH PR 4581 was preserved at the Manolo site (UT130831), (99.411 + 0.056/−0.061 Ma) above MAZ2 in the upper Mussentuchit (Figure 1).

Age data is based on a Bayesian age stratigraphic model (Trayler et al., 2020) of the member originally detailed in Tucker et al. (2023). Materials referable to Fona span the lower to upper Mussentuchit Member of the Cedar Mountain Formation, a range of, at minimum, 235,000 kyr. UT-16-07-22-Z1 and NCPALEOUT16 are located on land administered by the US Bureau of Land Management, respectively; exact locality information is restricted by federal statute and is available to qualified researchers via the NCSM.

  DIAGNOSIS: Fona herzogae is a small-bodied, early diverging ornithischian with the following unique combination of characters (autapomorphies are denoted with an asterisk) (Figure 5) *(1) a rostral maxillary fossa located caudal to the first tooth position (unknown in Oryctodromeus and possibly shared by Isaberrysaura and Haya); *(2) an otoccipital that bears a dorsoventrally elongate fossa on the medial surface of the occipital condyle located directly caudal to the medial opening of CN XII; *(3) a rostrocaudally oriented ventral canal on the prootic; *(4) The dorsal margin of the axis neural spine is parallel with the dorsal suture of the centrum, forming an angle of essentially ~0°. *(5) Ischial shaft has bulbous thickening along the dorsal margin directly distal to the obturator process (prominent on both ischia of at least two individuals and weakly present on only the right of another.) (6) base of the prepubic process bears a prominent lateral swelling (possibly present but significantly reduced in Oryctodromeus and Th. neglectus). (7) the caudoventral prong of the jugal's caudal process underlaps a groove along the ventral margin of the quadratojugal (shared by Th. neglectus, likely Changmiania, and possibly at least one specimen of Jeholosaurus [STMN 23–17]). (8) dentary teeth with vertical wear facets on the labial surface that terminate abruptly near the crown base to form a mesiodistally inclined shelf (shared by Oryctodromeus). (9) A low, round tuberosity on the medial side of the scapula located directly opposite to the glenoid ridge (shared with Oryctodromeus and possibly Iani smithi). Standard skeletal measurements of NCSM 33548 are provided in Table 1. Characters 7–9 serve as important synapomorphies that help place Fona within Thescelosaurinae.

Fona n. gen.

  Etymology: Fona (/Foat'NAH/) from the Austronesian language Finoʼ CHamoru. The ancestral maga'håga of the CHamoru people is Fo'na whose name can be translated as ‘the origin’. With her brother Pontan, whose name can be translated as ‘a ripe coconut’, they became the first paramount female and male chiefs (the ancestral maga'låhi of the CHamoru people), ancestrally venerated according to CHamoru tradition (Borja-Quichocho-Calvo, 2021; Cruz, 2022). According to oral history and legend, when Pontan's spirit began to perish and die, Fo'na discovers her powers and uses them to craft parts of Pontan's body into the pieces of the universe. His eyes were turned into the sun and moon, his eyebrows became the rainbows, his back the earth, his chest the sky, his blood the ocean, and from his stomach and penis the mountains and the sacred Creation Point stone pillar were born (Duhaylonsod & Cepeda, 2022). Fo'na had such sorrow from the loss of her brother that her tears flowed down his body to form the currents of the sea, and in reverence to her brother's dream, she decided to bring life to the universe, throwing herself into the earth where her body turned to stone. From her fossilized body sprang forth the first people at Fuha Rock, imbued with her good spirit (Cepeda, 2021; Cunningham, 1992; Perez, 2019; Perez, 2021). This ancestral story of the CHamoru people mirrors the life and death of the thescelosaurine dinosaurs at the Mini Troll locality, as there were at least two subadult individuals that may have been male and female, or perhaps siblings. Additionally, their bodies fell into the earth where they too fossilized. This naming, rooted in the story of Pontan's sacrifice and Fo'na's love for her brother, highlights the CHamoru values of inafa'måolek (to make good for all), geftåo (the need for compassion, selflessness, and familial bonds) (Duhaylonsod & Cepeda, 2022), the importance of the equality shared between women and men (Naholowa'a, 2018), and ongoing efforts to decolonize paleontology (Monarrez et al., 2021). 

Fona herzogae sp. nov.

  Etymology: The specific epithet honors Lisa Herzog (discoverer of the Mini Troll locality) for her unparalleled dedication to the paleontology program at the NCSM and the collection, care, and conservation of fossil specimens worldwide.

CONCLUSION: 

Fona herzogae adds to the cryptic diversity of the Mussentuchit Member dinosaur fauna, serving as an important component of this exceptional mid-Cretaceous ecosystem. It would have lived alongside the hadrosauromorph Eolambia caroljonesa (McDonald et al., 2017), the Rhabdadontomorph Iani smithi (Zanno, Gates, et al., 2023), the small-bodied tyrannosaur Moros intrepidus (Zanno, Tucker, et al., 2019), the large-bodied allosaurian Siats meekerorum (Zanno & Makovicky, 2013), an unnamed oviraptorosaur (Zanno, Avrahami, et al., 2019) and neoceratopsian (Zanno, Tucker, et al., 2023), and a collection of other terrestrial vertebrates (Avrahami et al., 2018).

The presence of a distinct thescelosaurine taxon in the Mussentuchit member supports the hypothesis that the ancestors of Thescelosaurus were present in North America as early as the Cenomanian, co-inhabiting the continent with their sister-taxon Orodrominae. To date, members of these clades have not been found together, suggesting different habitat preferences. Shared ecomorphology with, and a close phylogenetic affinity with Oryctodromeus demonstrated here, supports a shared semi-fossorial lifestyle. Some of the extensive intraspecific variation among specimens of Fona is likely attributable to ontogenetic transformations, whereas others may suggest a broad phenotypic range for the taxon or may point to sexual dimorphism.

 

Haviv M. Avrahami, Peter J. Makovicky, Ryan T. Tucker, Lindsay E. Zanno. 2024. A New semi-fossorial thescelosaurine Dinosaur from the Cenomanian-age Mussentuchit Member of the Cedar Mountain Formation, Utah. The Anatomical Record

DOI: doi.org/10.1002/ar.25505

https://sciences.ncsu.edu/news/life-underground-suited-new-dinosaur-fine 

[Paleontology • 2024] A Comprehensive Phylogenetic Analysis on early Ornithischian Evolution

 

 A Comprehensive Phylogenetic Analysis on early Ornithischian Evolution

in Fonseca, Reid, Venner, Duncan, Garcia & Müller, 2024.

 DOI: 10.1080/14772019.2024.2346577  

 x.com/Andre_O_Fonseca

Abstract

Resolving the evolutionary relationships of early diverging (‘basal’) ornithischian dinosaurs is a challenging topic in palaeontology, with multiple competing hypotheses on the phylogenetic relationships of heterodontosaurids, ‘hypsilophodontids’, and other early-diverging forms. These hypotheses cannot be directly compared because they are derived from differently constructed datasets (i.e. distinct samples of taxa and characters). This study aims to address these issues by revising and combining the distinct datasets into a single analysis in order to create the most comprehensive dataset for the investigation of the phylogenetic relationships of early-diverging ornithischians. A diphyletic model of Dinosauria is supported, with silesaurs nesting as members of Ornithischia. Heterodontosauridae is resolved as a clade of non-genasaurian ornithischians, rejecting a potential relationship with Marginocephalia. ‘Hypsilophodontid’ taxa span the neornithischian and ornithopod stem, with Thescelosauridae as the sister taxon to Cerapoda. A more restricted Ornithopoda is composed of five main clades: Hypsilophodontidae, Rhabdodontomorpha, Elasmaria, Dryosauridae and Ankylopollexia. Hypsilophodontidae is a valid clade, reduced to two European Barremian taxa. Rhabdodontomorpha does not contain Muttaburrasaurus as originally proposed, but instead expands to include a North American clade formed by Convolosaurus, Iani and Tenontosaurus. Elasmaria contains all non-dryomorph Gondwanan ornithopods, with its members possessing multiple distinct body plans. New results and comparison with previous studies suggest that some members of Dryosauridae are not ‘true dryosaurids’ but various early euiguanodontians that may be more closely related to either Elasmaria or Ankylopollexia. Results group most ‘hypsilophodontids’ in larger clades, significantly reducing the number and extension of ghost lineages throughout all of Neornithischia. These clades also show a degree of endemism, with different lineages present at different continents in the Late Cretaceous. This new phylogenetic analysis unifying previous works will provide a framework for future studies on origins and relations of early diverging ornithischians, and attempting to find stability among the different competing hypotheses.

Keywords: Silesauridae, Heterodontosauridae, Thyreophora, Neornithischia, Ornithopoda, Marginocephalia

 

André O. Fonseca, Iain J. Reid, Alexander Venner, Ruairidh J. Duncan, Mauricio S. Garcia and Rodrigo T. Müller. 2024. A Comprehensive Phylogenetic Analysis on early Ornithischian Evolution. Journal of Systematic Palaeontology. 22(1); 2346577. DOI: 10.1080/14772019.2024.2346577 

 x.com/Andre_O_Fonseca/status/1804154614607909152

 

[Paleontology • 2023] Neuroanatomy of the late Cretaceous Thescelosaurus neglectus (Neornithischia: Thescelosauridae) reveals novel ecological specialisations within Dinosauria

Thescelosaurus neglectus

in Button & Zanno, 2023. 

DOI: 10.1038/s41598-023-45658-3

 twitter.com/ExpeditionLive

Artwork: Anthony Hutchings

Abstract

Ornithischian dinosaurs exhibited a diversity of ecologies, locomotory modes, and social structures, making them an ideal clade in which to study the evolution of neuroanatomy and behaviour. Here, we present a 3D digital reconstruction of the endocranial spaces of the latest Cretaceous neornithischian Thescelosaurus neglectus, in order to interpret the neuroanatomy and paleobiology of one of the last surviving non-avian dinosaurs. Results demonstrate that the brain of Thescelosaurus was relatively small compared to most other neornithischians, instead suggesting cognitive capabilities within the range of extant reptiles. Other traits include a narrow hearing range, with limited ability to distinguish high frequencies, paired with unusually well-developed olfactory lobes and anterior semicircular canals, indicating acute olfaction and vestibular sensitivity. This character combination, in conjunction with features of the postcranial anatomy, is consistent with specializations for burrowing behaviours in the clade, as evidenced by trace and skeletal fossil evidence in earlier-diverging thescelosaurids, although whether they reflect ecological adaptations or phylogenetic inheritance in T. neglectus itself is unclear. Nonetheless, our results provide the first evidence of neurological specializations to burrowing identified within Ornithischia, and non-avian dinosaurs more generally, expanding the range of ecological adaptations recognized within this major clade.

 

David J. Button and Lindsay E. Zanno. 2023. Neuroanatomy of the late Cretaceous Thescelosaurus neglectus (Neornithischia: Thescelosauridae) reveals novel ecological specialisations within Dinosauria. Scientific Reports. 13: 19224. DOI: 10.1038/s41598-023-45658-3

 twitter.com/ExpeditionLive/status/1721879200234340466

[Paleontology • 2023] Minimocursor phunoiensis • A New Basal Neornithischian Dinosaur from the Phu Kradung Formation (Upper Jurassic) of Northeastern Thailand

Minimocursor phunoiensis  

Manitkoon, Deesri, Khalloufi, Nonsrirach, Suteethorn, Chanthasit, Boonla & Buffetaut, 2023

มินิโมเคอร์เซอร์ ภูน้อยเอนซิส  ||  DOI: 10.3390/d15070851

Drawings by Wongwech Chowchuvech and Sita Manitkoon. 

Abstract

An exceptional articulated skeleton of a new basal neornithischian dinosaur, Minimocursor phunoiensis gen. et sp. nov., was discovered in the Late Jurassic Phu Kradung Formation at the Phu Noi locality, Kalasin Province, Thailand, a highly productive non-marine fossil vertebrate locality of the Khorat Plateau. It is one of the best-preserved dinosaurs ever found in Southeast Asia. Minimocursor phunoiensis gen. et sp. nov. shows a combination of both plesiomorphic and apomorphic characters resembling those of Late Jurassic to Early Cretaceous small-bodied ornithischians from China: a low subtriangular boss is projected laterally on the surface of the jugal, the brevis shelf of the ilium is visible in lateral view along its entire length, a distinct supraacetabular flange is present on the pubic peduncle of the ilium, the prepubis tip extends beyond the distal end of the preacetabular process of the ilium, and the manus digit formula is ?-3-4-3-2. The phylogenetic analysis shows that this dinosaur is among the most basal neornithischians. This study provides a better understanding of the early evolution and taxonomic diversity of ornithischians in Southeast Asia.

Keywords: ornithischia; Southeast Asia; Khorat Plateau; Late Jurassic; Minimocursor phunoiensis

Skull of Minimocursor phunoiensis gen. et sp. nov. based on PRC 150 in left lateral view. Outline reconstruction of the skull (A); outline reconstruction of the skull with photos of the jugal (reversed), surangular, and angular (B); right jugal (C); and left surangular and angular (D). Scale bars: 1 cm.

Left dentary (PRC 149) referred to Minimocursor phunoiensis gen. et sp. nov. from Phu Noi locality in labial (A), dorsal (B), and lingual views (C). Dentary teeth in labial (D) and lingual (E) views.

Holotype of Minimocursor phunoiensis gen. et sp. nov., PRC 150, in left lateral view.

Photograph (A) and interpretative drawing (B).

Reconstruction of Minimocursor phunoiensis gen. et sp. nov. (PRC 150) in left lateral view (except reversed images of the right jugal). Recovered elements of the holotype shown in white (A); holotype with referred materials, which are not to scale, shown in light purple (B); and life restoration (C).

Drawings by Wongwech Chowchuvech (A, B) and Sita Manitkoon (B).

Systematic Palaeontology

Dinosauria Owen, 1842 

Ornithischia Seeley, 1888  

Neornithischia Cooper, 1985  

 

Minimocursor gen. nov.

 

Minimocursor phunoiensis gen. et sp. nov.

Diagnosis. Ornithischian dinosaur distinguished by a unique combination of plesiomorphic and apomorphic characters resembling those of basal neornithischians: jugal posterior process bifurcated distally (present in Lesothosaurus, Jeholosaurus, Psittacosaurus, and some early thyreophorans including Emausaurus and Scelidosaurus); a low flattened subtriangular boss projects laterally on the surface of the jugal (report in Changchunsaurus, and some early ornithischians including Manidens and Lioceratops); the pre-caudal axial skeleton is composed of 15 dorsals and 5 sacrals (presente in Lesothosaurus, Agilisaurus and Hexinlusaurus); the brevis shelf of the ilium is visible in lateral view along its entire length (present in Agilisaurus, Sanxiasaurus and Lesothosaurus); a distinct supraacetabular flange is present on the pubic peduncle of the ilium (present in Agilisaurus, Sanxiasaurus, and some early thyreophorans including Scutellosaurus and Scelidosaurus).

Type locality and horizon. Phu Noi locality (a small hill as the Thai name indicates), Ban Din Chi Sub-district, Kham Muang District, Kalasin Province, Thailand; Upper Jurassic Phu Kradung Formation, Khorat Group. This locality is part of the Kalasin Geopark area.

Etymology. The generic name is from the Latin ‘minimus’, ‘the smallest’, referring to the holotype individual, which is smaller than any other neornithischians from the site, combined with the suffix ‘-cursor’, the Latin word for runner. The specific epithet is derived from the excavation site, Phu Noi.

Articulated dorsal vertebrae of Minimocursor phunoiensis gen. et sp. nov., PRC 150, with close-up on the ossified tendons, under UV light.

Locality map and stratigraphy of Phu Noi locality, which has yielded the holotype of Minimocursor phunoiensis gen. et sp. nov. Map of Thailand, showing the location of Bangkok and Kalasin Province (A); map of Khorat Plateau, showing the distribution of the Lower Phu Kradung Formation and the location of Phu Noi locality (red star) (B); stratigraphic column of Phu Noi (modified from [26]) (C); photograph of the excavation site in 2023 (D).

Palaeoenvironmental interpretation of the Late Jurassic Phu Kradung Formation of northeastern Thailand, including
hybodont indet. with egg capsules (A), Acrodus kalasinensis (B), ptycholepid indet. (C), Isanichthys lertboosi (D), Ferganoceratodus annekempae (E), brachyopid indet. (F), Phunoichelys thirakupti (G), Kalasinemys prasarttongosothi (H), Indosinosuchus potamosiamensis (I), mamenchisaurid indet. (J), metriacanthosaurid indet. (K), stegosaur indet. (L), Minimocursor phunoiensis (M), and rhamphorhynchoid indet. (N).

 Drawing by Sakka Weerataweemat.

Conclusions

The Phu Noi locality contains a wealth of specimens and has yielded an exceptionally articulated skeleton, which represents one of the best-preserved dinosaurs ever found in Southeast Asia. This is the earliest record of neornithischians in Southeast Asia, and the first dinosaur taxon named from the Phu Kradung Formation of Thailand. This finding increases diversity and helps to elucidate the evolution of basal neornithischian dinosaurs in this region. Many of the remaining bones are still under preparation, including another skull. These unpublished specimens may provide a better understanding of the biology of Minimocursor phunoiensis gen. et sp. nov. in the future.

This study also provides new palaeontological data to illustrate the palaeoecosystem to the general public, as well as improving the academic value of the Kalasin Geopark.

  Sita Manitkoon, Uthumporn Deesri, Bouziane Khalloufi, Thanit Nonsrirach, Varavudh Suteethorn, Phornphen Chanthasit,Wansiri Boonla and Eric Buffetaut. 2023. A New Basal Neornithischian Dinosaur from the Phu Kradung Formation (Upper Jurassic) of Northeastern Thailand. Diversity. 15(7), 851. DOI: 10.3390/d15070851

  facebook.com/PaleoToon/posts/787863516672516

 (This article belongs to the Collection Feature Papers in Phylogeny and Evolution)

 

[Paleontology • 2019] Ferrisaurus sustutensis • A New Leptoceratopsid Dinosaur from Maastrichtian-aged Deposits of the Sustut Basin, northern British Columbia, Canada

Ferrisaurus sustutensis

 Arbour & Evans, 2019

DOI: 10.7717/peerj.7926 

 twitter.com/VictoriaArbour 

Abstract 

A partial dinosaur skeleton from the Sustut Basin of northern British Columbia, Canada, previously described as an indeterminate neornithischian, is here reinterpreted as a leptoceratopsid ceratopsian, Ferrisaurus sustutensis, gen. et. sp. nov. The skeleton includes parts of the pectoral girdles, left forelimb, left hindlimb, and right pes. It can be distinguished from other named leptoceratopsids based on the proportions of the ulna and pedal phalanges. This is the first unique dinosaur species reported from British Columbia, and can be placed within a reasonably resolved phylogenetic context, with Ferrisaurus recovered as more closely related to Leptoceratops than Montanoceratops. At 68.2–67.2 Ma in age, Ferrisaurus falls between, and slightly overlaps with, both Montanoceratops and Leptoceratops, and represents a western range extension for Laramidian leptoceratopsids.

Systematic palaeontology

DINOSAURIA Owen, 1842

ORNITHISCHIA Seeley, 1888

NEORNITHSICHIA Cooper, 1985

MARGINOCEPHALIA Sereno, 1986

CERATOPSIA Marsh, 1890

NEOCERATOPSIA Sereno, 1986

CORONOSAURIA Sereno, 1986

LEPTOCERATOPSIDAE Nopcsa, 1923

FERRISAURUS SUSTUTENSIS gen. et sp. nov.  

Diagnosis: Ferrisaurus can be differentiated from other known leptoceratopsids based on the following unique combination of characters: penultimate pedal phalanges in digits III and IV are equal or subequal in proximodistal length compared to the length of the preceding phalanx, rather than shorter as in all other leptoceratopsids for which these elements are preserved except possibly USNM 13863 (Cerasinops); astragalus and tibia coossified, unlike all other leptoceratopsids except for AMNH 5464 (Montanoceratops); distal end of ulna broader relative to radius length than in Leptoceratops; distal end of ulna medially bowed, unlike the straight ulna of the penecontemporaneous Maastrichtian taxa Leptoceratops and Montanoceratops, but similar to Cerasinops and Prenoceratops from the Campanian.

Etymology: “Iron lizard,” from Latin ferrum (=iron) and Greek sauros (=lizard), in reference to the specimen’s discovery along a railway line, and sustutensis in reference to its provenance near the Sustut River and within the Sustut Basin.

Holotype: RBCM P900, a partial skeleton consisting of a partial right coracoid, fragmentary left scapula, complete left radius, distal portion of the left ulna, associated distal two thirds of the left tibia and fibula and coossified astraglus and ?calcaneum, partial articulated digits III and IV of the right pes, and an unprepared block removed from the posterior surface of the tibia that appears to contain four metatarsals, presumably from the left pes. Previously catalogued as RBCM.EH2006.019.0001 to RBCM.EH2006.019.010 and published under RBCM.EH2006.019 by Arbour & Graves (2008).

Locality: RBCM P900 was discovered near the confluence of Birdflat Creek and the Sustut River in the Sustut Basin (Fig. 1); the bones were found loose in the rubble during construction along the BC Rail line, which has since been abandoned. Fieldwork in the Sustut Basin in 2017 provided strong support for the relocation of the original collection site a few hundred meters from the confluence of the Sustut River and Birdflat Creek (Arbour et al. (in press)); exact GPS coordinates are on file at the Royal BC Museum.

Formation and Age: Tatlatui Member, Tango Creek Formation, Sustut Group. Palynomorphs recovered from the presumed holotype locality included the Maastrichtian marker taxon Pseudoaquilapollenites bertillonites, indicating an age of approximately 68.2–67.2 Ma for the site (Arbour et al. (in press)).

  

Victoria M. Arbour and David C. Evans. 2019.  A New Leptoceratopsid Dinosaur from Maastrichtian-aged Deposits of the Sustut Basin, northern British Columbia, Canada. PeerJ. 7:e7926. DOI:  10.7717/peerj.7926

twitter.com/VictoriaArbour/status/1192403825577082880

[Paleontology • 2019] Convolosaurus marri • A New Basal Ornithopod (Dinosauria: Ornithischia) from the Early Cretaceous of Texas, USA

Convolosaurus marri

Andrzejewski, Winkler & Jacobs, 2019

 DOI: 10.1371/journal.pone.0207935

Abstract

Material from a minimum of twenty-nine individuals of a new ornithopod, represented by nearly every skeletal element, was recovered from the Proctor Lake locality in the Twin Mountains Formation (Aptian) of north-central Texas. This material includes various ontogenetic stages, providing insight into the growth patterns of this species. The new ornithopod, Convolosaurus marri gen. et sp. nov., is recovered outside of Iguanodontia, but forms a clade with Iguanodontia exclusive of Hypsilophodon foxii. The presence and morphology of four premaxillary teeth along with a combination of both basal and derived characters distinguish this taxon from all other ornithopods. Basal characters present in C. marri including the presence of premaxillary teeth, the shape of the dentary teeth, and position of the pterygoid wing on the quadrate, whereas the presence of opisthocoelous cervical vertebrae, large proximal caudal neural spines, and curved maxillary tooth roots suggest C. marri is more derived than 80% of the basal neornithischians included in this analysis.

Fig 2. Convolosaurus marri, articulated specimens.
 (A) SMU 70456, articulated subadult individual on display at the Proctor Lake Corps of Engineers Office. Scale arrow equals 10 cm. (B) Composite skeleton on display at the Perot Museum of Nature and Science. Scale bar equals 10 cm. (C) SMU 75379 and SMU 75380, partial articulated skeletons found stacked on one another. Scale bar equals 5 cm.

Fig 4. Skull reconstruction. Skull reconstruction of Convolosaurus marri based on available specimens.

Abbreviations: A-articular, BO-basioccipital, D-dentary, F-frontal, J-jugal, L-lacrimal, MX-maxilla, N-nasal, OP-opisthotic, P-parietal, PD-predentary, PF-prefrontal, PMX-premaxilla, PO-postorbital, Q-quadrate, QJ-quadratojugal, SA-surangular, SOB-supraorbital, SQ-squamosal.

Fig 6. SMU 72834 anterior skull. (A) SMU 72834, anterior skull in right lateral view. (B) Illustration of SMU 72834, in right lateral view (David Baker).

Abbreviations: D-dentary, L-lacrimal, MX-maxilla, PMX-premaxilla, PD-predentary, QJ-quadratojugal. Scale bar equals 5 cm.

Systematic Paleontology

DINOSAURIA Owen, 1842

ORNITHISCHIA Seeley, 1887

NEORNITHISCHIA Cooper, 1985

CERAPODA Sereno, 1986

ORNITHOPODA Marsh, 1881

Convolosaurus marri gen. et sp. nov. 

Holotype: SMU 72834, a skull and partial articulated skeleton with 9 cervical vertebrae; 15 dorsal vertebrae; 6 sacral vertebrae; 23 caudal vertebrae; right and partial left scapula; right and partial left coracoids; left and partial right humeri; left ulna; left radius; partial left manus; articulated pelvis including the left and right ilia, proximal left and right ischia, partial prepubic rods; proximal and distal ends of the left and right femora and the mid-part of the left shaft; proximal left and right tibiae; and proximal left fibula. The type specimen, SMU 72834, is the largest individual in the sample measuring approximately 2.5–3 m in length; however, this skeleton does not represent a full grown adult, thus the adult size of this species in unknown.

Diagnosis: The presence of four premaxillary teeth with proximodistally oriented sulcus on the buccal surface distinguishes Convolosaurus marri gen. et sp. nov. from all other ornithopods. Further, it can be distinguished from other basal ornithopods by a unique combination of primitive and derived character states. Primitive character states include the presence of premaxillary teeth and two supraorbitals that extend across the entire orbit. Derived character states include: curved maxillary tooth roots; opisthocoelous cervical vertebrae; sacral neural spines twice the height of the sacral centra; proximal caudal neural spines 1.5 times the height of the centrum; expanded ischial ‘foot’; shallow intercondylar groove on the anterior surface of the femur; and a laterally compressed prepubic process.

Etymology: The generic name Convolosaurus translates from Latin meaning “flocking lizard” referring to clusters of juvenile specimens. The species name marri is in honor of Dr. Ray H. Marr who produced the Society of Vertebrate Paleontology videos “We are SVP” and “About the SVP Logo” posted on the SVP website (vertpaleo.org), and who is a strong proponent of students at Southern Methodist University (SMU).

Fig 30. Strict consensus tree produced from phylogenetic analysis. Strict consensus tree of 96 most parsimonious trees recovered from phylogenetic analysis. Bootstrap support values >50% listed beneath nodes.

   

Conclusions: 

The Proctor Lake fossil locality contains a wealth of specimens providing not only nearly complete individual skeletons, but also insight into ontogeny and population structure. The femoral length distribution of 29 individuals from the Proctor Lake locality indicates a high mortality rate among the smallest and presumably youngest individuals. Clusters of individuals of varying sizes suggest individuals flocked together long after hatching perhaps for protection against predators. The specimens recovered from Proctor Lake reveal a new species of basal ornithopod with a unique set of both basal and derived characters. Characters including an expanded ischial foot, curved maxillary tooth roots, and opisthocoelus cervical vertebrae position Convolosaurus marri in a clade exclusive of most basal ornithischians including Hypsilophodon foxii [Galton, 1974], but characters such as the presence of premaxillary teeth, shape of the frontals, and the position of the pterygoid wing on the quadrate position C. marri outside of Iguanodontia. Thus, this new species provides crucial information on the evolution of basal neornithischians.

 Kate A. Andrzejewski, Dale A. Winkler and Louis L. Jacobs. 2019. A New Basal Ornithopod (Dinosauria: Ornithischia) from the Early Cretaceous of Texas.  PLoS ONE 14(3): e0207935. DOI: 10.1371/journal.pone.0207935