Yuong-Nam Lee

Korea Institute of Geoscience and Mineral Resources | KIGAM · Geological Museum

Numerous non-avian dinosaurs possessed pennaceous feathers on their forelimbs (proto-wings) and tail. Their functions remain unclear. We propose that these pennaceous feathers were used in displays to flush hiding prey through stimulation of sensory-neural escape pathways in prey, allowing the dinosaurs to pursue the flushed prey. We evaluated the...

The study of the large paraphyletic group of extinct ‘palaeoniscoid’ fishes has shed light on the diversity and evolutionary history of basal actinopterygians. However, only a little ontogenetic information about ‘palaeoniscoids’ is known because their records in the early stages of development are scarce. Here, we report on a growth series of ‘pal...

We present here a natural cranial endocast assigned to an abelisaurid theropod found in Cretaceous rocks of the outcropping Bajo de la Carpa Formation (Santonian) in Neuquén Province, Northern Patagonia, Argentina. The specimen was found in association with fragmentary braincase remains, which include an otic capsule and part of the skull roof. The...

Mongolia has a long history of discoveries and research related to dinosaur eggs. Since the first scientific discoveries in the early 1920s, numerous eggs, eggshells, and nests have been collected by various international expeditions and have contributed significantly to our understanding of reproductive traits in dinosaurs. In this study, we repor...

Numerous non-avian dinosaurs possessed pennaceous feathers on their forelimbs (proto-wings) and tail (caudal plumage). Their functions remain unclear. We propose that the pennaceous feathers were used in displays to flush prey through stimulation of sensory-neural escape pathways in prey, and to provide higher speed and maneuverability during pursu...

The avian palaeognath phylogeny has been recently revised significantly due to the advancement of genome-wide comparative analyses and provides the opportunity to trace the evolution of the microstructure and crystallography of modern dinosaur eggshells. Here, eggshells of all major clades of Palaeognathae (including extinct taxa) and selected eggs...

Numerous non-avian dinosaurs possessed pennaceous plumage in the proto-wing and tail ¹ , whose function remains unclear. We hypothesize that they might have been used during hunting that resembles avian flush-pursuers, who use wing/tail displays to flush hidden prey and pursue it 2,3 . Using a dinosaur robot, we confirmed that efficiency in flushin...

Streamlining a body is a major adaptation for aquatic animals to move efficiently in the water. Whereas diving birds are well known to have streamlined bodies, such body shapes have not been documented in non-avian dinosaurs. It is primarily because most known non-avian theropods are terrestrial, barring a few exceptions. However, clear evidence of...

The avian palaeognath phylogeny has been recently revised significantly due to the advancement of genome-wide comparative analyses and provides the opportunity to trace the evolution of the microstructure and crystallography of modern dinosaur eggshells. Here, eggshells of all major clades of Palaeognathae (including extinct taxa) and selected eggs...

Here we report a new articulated skeleton of Yamaceratops dorngobiensis (MPC-D 100/553) from the Khugenetjavkhlant locality at the Shine Us Khudag (Javkhlant Formation, ?Santonian-Campanian) of the eastern Gobi Desert, Mongolia, which represents the first substantially complete skeleton and the first juvenile individual of this taxon. The specimen...

A new ankylosaurid dinosaur, Tarchia tumanovae sp. nov., has been recovered from the Upper Cretaceous Nemegt Formation of Mongolia. It includes a well-preserved skull, dorsal, sacral, caudal vertebrae, sixteen dorsal ribs, ilia, a partial ischium, free osteoderms, and a tail club. The squamosal horns of T. tumanovae are divided into two layers, the...

Dinosaur egg-bearing deposits of the Upper Cretaceous (Coniacian-Santonian) Wido Volcanics at Wi Island, South Korea, were studied from a taphonomic perspective to improve understanding of nesting behavior. Based on facies, bedset geometry, and other sedimentological characteristics, the section can be classified into three facies associations: (1)...

The Late Cretaceous dinosaur record in southern South America has been improved recently; particularly with findings from Chorrillo and Cerro Fortaleza formations, both bearing ankylosaur remains, a clade that was not previously recorded in the Austral Basin. The dinosaur fauna of the type locality of Cerro Fortaleza Formation is known from -and bi...

A new dinosaur tracksite with footprints of non-adult ornithopods was discovered from the Lower Cretaceous Haman Formation (Albian), Gunbuk District, Haman County, South Gyeongsang Province of South Korea in 2018. The tracksite consists of 58 ornithopod footprints (seven short trackways and 26 isolated footprints) within three track-bearing horizon...

A new articulated postcranial specimen of an indeterminate ankylosaurid dinosaur from the Upper Cretaceous (middle-upper Campanian) Baruungoyot Formation from Hermiin Tsav, southern Gobi Desert, Mongolia includes twelve dorsal vertebrae, ribs, pectoral girdles, forelimbs, pelvic girdles, hind limbs, and free osteoderms. The new specimen shows that...

The most austral South American ankylosaur record correspond to the preliminary report of an isolate tooth recovered from a microsite (MPM-PV-18805, Museo Padre Molina, Río Gallegos) at Cerro Fortaleza (Cerro Fortaleza Formation, Campanian-Maastrichtian), in Southern Patagonia. Associate materials were recently identified as interstitial armor ossi...

Here we report a new quadrupedal trackway found in the Lower Cretaceous Daegu Formation (Albian) in the vicinity of Ulsan Metropolitan City, South Korea, in 2018. A total of nine manus-pes imprints show a strong heteropodous quadrupedal trackway (length ratio is 1:3.36). Both manus and pes tracks are pentadactyl with claw marks. The manus prints ro...

A new genus and species of redfieldiiform fish, Hiascoactinus boryeongensis gen. et sp. nov., is described based on a nearly complete specimen from the Upper Triassic Amisan Formation of South Korea. Hiascoactinus is distinguished from other redfieldiiforms by having a barely ornamented dermal skull surface except for the snout region, two heteromo...

While there are now numerous records of dinosaurs from Cretaceous rocks around the state of Alaska, very few fossil records of terrestrial vertebrates are known from the Mesozoic rocks of the southwestern part of the state. Here we report the new discovery of extensive occurrences of dinosaur tracks from Aniakchak National Monument of the Alaska Pe...

Alvarezsaurid diversity has been markedly increased by recent discoveries from China. However, the number of alvarezsaurid specimens in the Nemegt Formation of Mongolia remained low since the initial report on Mononykus olecranus in 1993. Here we report three new alvarezsaurid specimens from this formation, which were associated with each other and...

Colonial nesting behavior has been inferred in a variety of non-avian dinosaurs based on high concentrations of nests preserved in an area, but sedimentologic and taphonomic evidence demonstrating the contemporaneity of the nests is often lacking. A new nesting site discovered in the Upper Cretaceous Javkhlant Formation of the eastern Gobi Desert,...

Crocodyliform tracks are reported from the Upper Cretaceous ?Cenomanian-Santonian) Bayanshiree Formation in southeastern Mongolia. Ten tracks are preserved as natural casts, forming a trackway with a quadrupedal gait pattern with a tail trail. All tracks are short and wide, and dominated by toe traces without plantar impressions. Pes tracks are cha...

Recent discoveries of new oviraptorosaurs revealed their high diversity from the Cretaceous Period in Asia and North America. Particularly, at the family level, oviraptorids are among the most diverse theropod dinosaurs in the Late Cretaceous of Mongolia and China. A new oviraptorid dinosaur Gobiraptor minutus gen. et sp. nov. from the Upper Cretac...

Strict consensus of 24 most parsimonious trees of 652 steps with synapomorphies obtained by TNT. (TIF)

Selected measurements of the holotype specimen (MPC-D 102/111) of Gobiraptor minutus gen. et sp. nov. (XLSX)

Additional images of the cranial elements of the holotype specimen (MPC-D 102/111) of Gobiraptor minutus gen. et sp. nov. (A) Premaxillae and left maxilla in ventral view. (B) Right premaxilla in lateral view. (C) Right quadratojugal and quadrate in lateral view. (D) Rostral region of the mandible in caudal (D) view. (E-F) Caudal region of the righ...

Additional images of the postcranial elements of the holotype specimen (MPC-D 102/111) of Gobiraptor minutus gen. et sp. nov. (A-B) Left femur in caudal (A) and medial (B) views. (C) Right humerus in cranial view. (D) Right ilium in medial view. (E) Left metatarsal I and pedal digit I in medial view. (F) Left pedal digit IV in lateral view. Abbrevi...

Data matrix of Oviraptorosauria and outgroups used in this study (modified from Lü et al. [20]). (DOCX)

The site of Altan Uul III where the holotype specimen (MPC-D 102/111) of Gobiraptor minutus gen. et sp. nov. was found in 2008. (TIF)

We report details of a unique association of hadrosaur and therizinosaur tracks found in the Late Cretaceous lower Cantwell Formation, Denali National Park, central Alaska Range, Alaska. This rock unit is now well-documented as a source of thousands of fossil footprints of vertebrates such as fishes, pterosaurs, and avialan and non-avialan dinosaur...

South Korea has become globally famous for various tetrapod footprints from Upper Cretaceous strata. Here we report the first Early Cretaceous “large” tracksite from the Sanbukdong Formation of an unnamed small basin in the west of Gunsan City, North Jeolla Province. The tracksite (720 m²) produced 425 tracks. Among them, eleven ornithopod and thre...

Four heteropod lizard trackways discovered in the Hasandong Formation (Aptian-early Albian), South Korea assigned to Sauripes hadongensis, n. ichnogen., n. ichnosp., which represents the oldest lizard tracks in the world. Most tracks are pes tracks (N = 25) that are very small, average 22.29 mm long and 12.46 mm wide. The pes tracks show "typical"...

To date, only three pachycephalosaur specimens have been reported from the Nemegt Formation, two of which are holotypes (Homalocephale calathocercos and Prenocephale prenes) and all of which were collected from the classic Nemegt locality. Here, we describe several new cranial specimens from this formation, but which originate from Bügiin Tsav, Gur...

Ankylosaur braincase and endocranial morphologies are poorly known. Furthermore, cranial endocasts have been described for fewer than ten taxa so far. The complete inner ear morphology is known for only three species – Euoplocephalus tutus, Kunbarrasaurus ieversi, and Pawpawsaurus campbelli. Here, the first cranial endocast morphologies are present...

A theropod tracksite was discovered in the Nemegt Formation (Maastrichtian) at Bügiin Tsav, Mongolia by the Korea-Mongolia International Dinosaur Project in 2009. A total of 67 tracks (14 trackways [one didactylous, 13 tridactylous] and 12 isolated tracks) belonging to four ichnomorphotypes were mapped on a single horizon. This indicates at least f...

Background Ankylosaurs are one of the least explored clades of dinosaurs regarding endocranial anatomy, with few available descriptions of braincase anatomy and even less information on brain and inner ear morphologies. The main goal of this study is to provide a detailed description of the braincase and internal structures of the Early Cretaceous...

The Ganzhou area of Jiangxi Province, southern China is becoming one of the most productive oviraptorosaurian localities in the world. A new oviraptorid dinosaur was unearthed from the uppermost Upper Cretaceous Nanxiong Formation of Ganzhou area. It is characterized by an anterodorsally sloping occiput and quadrate (a feature shared with Citipati)...

The bone microstructure of Deinocheirus mirificus, a gigantic ornithomimosaur from the Late Cretaceous of Mongolia was studied. The bone samples were extracted from thoracic ribs of two individuals: MPC-D 100/128 and a larger MPC-D 100/127. Each rib sample was cross-cut at two different levels providing thus material for four thin petrographic sect...

The holotype of Deinocheirus mirificus was collected by the 1965 Polish-Mongolian Palaeontological Expedition at Altan Uul III in the southern Gobi of Mongolia. Because the holotype consists mostly of giant forelimbs (2.4 m in length) with scapulocoracoids, for almost 50 years Deinocheirus has remained one of the most mysterious dinosaurs. The mosa...

Ankylosaur braincase and endocranial morphology is in general poorly known, and only the cranial endocast and inner ear of Euoplocephalus, an ankylosaurid from North America, and the cranial endocasts of Sauropelta and another unnamed nodosaurid from Japan have been described in detail. The first 3D reconstructions of the brains and inner ears of t...

Herein we describe deinonychosaurian (Dinosauria: Theropoda) tracks in the Lower Cretaceous Hekou Group at sites I and II of Liujiaxia Dinosaur National Geopark, Gansu Province, China. The site preserves 71 didactyl tracks, the largest concentration of deinonychosaurian tracks in Asia. The tracks pertain to a new dromaeopodid ichnospecies: Dromaeos...

Bite marks attributable to Tarbosaurus bataar are identified on fragments of gastralia from the giant putative ornithomimosaur, Deinocheirus mirificus. Hundreds of bone fragments collected from the holotype quarry of D. mirificus by members of the Korea-Mongolia International Dinosaur Project at Altan Uul III (Mongolia) were visually inspected for...

Two unusual, well-preserved, tridactyl trackways associated with sinuous grooves from the Lower Cretaceous Yanguoxia tracksite (Yongjing County, Gansu Province, China) are described and the behavior they present is discussed. The sinuous grooves are protracted and simple, with high percent interruption metric values and a low sinuosity. They are lo...

A partial skeleton of the ornithomimid dinosaur, discovered from the Late Cretaceous Qiupa Formation of Luanchuan County, Tantou Basin, Henan Province, China, is described here and assigned to a new genus and species, Qiupalong henanensis, with unique features (a notch on the lateral surface of the lateral posterior process of the proximal end of t...

Measurements of Koreaceratops hwaseongensis, gen. et sp. nov. (in millimeters). Asterisk indicates as preserved

Character-taxon matrix (21 taxa, 136 characters). Data matrix is compiled by adding three new characters (char. 134–136) to a NEXUS version of the matrix of Makovicky and Norell (2006) and Makovicky

In 2008, a new basal neoceratopsian was discovered in the Tando beds (Albian) of Tando Basin in South Korea. It represents the first ceratopsian dinosaur in the Korean peninsula and is assigned to Koreaceratops hwaseongensis gen. et sp. nov. Autapomorphies of Koreaceratops include very tall neural spines over five times higher than the associated c...

In 1990, five well-preserved pterosaur trackways were discovered in the Kitadani Formation (Lower Cretaceous) of the Kitadani Dinosaur Quarry, Fukui Prefecture, Japan. They occur on the surface of an isolated dark grey siltstone slab (70×50cm) along with amphibian and bird tracks as well as feeding marks. All pterosaur trackways (a total of 64 impr...

The partial carapace of a “macrobaenid” turtle from the Geoncheonri Formation (Lower Cretaceous) in Gyeongsan City near Daegu Metropolian City, South Korea, is referred to Kirgizemys Nessov and Khozsatzky, 1973. The specimen most closely resembles K. exaratus Nessov and Khozsatzky, 1973 from the Albian of Kyrgyzstan. It is the first turtle fossil d...

New material of dsungaripterid pterosaurs from the Early Cretaceous of Tatal, western Mongolia, allows the diagnoses of Dsungaripteridae and Noripterus to be amended. All pterosaurs found at Tatal belong to Dsungaripteridae (either Dsungaripterus or Noripterus). The name Phobetor is a junior synonym of Noripterus. The differing shapes of the anteri...

Although vertebrate paleontology has lagged behind invertebrate paleontology in Korea, an increase in the rate of discovery of Cretaceous vertebrate fossils in recent years resulted in documentation of 38 localities from the fluvio-lacustrine Gyeongsang Supergroup (Hauterivian to Cenomanian) and recovery of fish, turtle, crocodilian, pterosaur, and...

One hundred and five sauropod tracks were excavated from black shale of the Uhangri Formation (upper Cretaceous), Haenam County, South Chulla Province, Korea. The tracks are true manus prints (not undertracks) and were made by sauropod dinosaurs while swimming.

In 2004, fifty new pterosaur tracks were discovered in the Hasandong Formation (Lower Cretaceous), South Korea. They are preserved as natural casts on the surface of an isolated dark grey mudstone block (70 × 50 cm). Manus and pes imprints are very small, averaging 25.6 mm and 25.7 mm long, respectively. The manus imprints (N = 25) are tridactyl an...

A tyrannosauroid premaxillary tooth has been discovered for the first time in the Hasandong Formation (Lower Cretaceous) in South Korea. Carinae on the tooth form both the mesial and distal edges of the lingual face, producing a “D-shaped” cross section typical of tyrannosauroids. The Korean premaxillary tooth is different from those of other known...

A psittacosaurid dinosaur from western Liaoning, China, possessing a pathological fibula is described. The pathological fibula is significantly different from a normal fibula, being shorter and much stouter, and with a distinct swelling on the shaft. The swollen portion (representing a mass of necrotic bone) of the fibula indicates that the animal...

The Early Cretaceous is rapidly being recognized as a crucial time in the origin and dispersal of living vertebrate groups. Cretaceous trackways in Korea are among the most abundant in the world and include the smallest sauropod tracks known, plus four avian ichnotaxa, one of which is the earliest record of a bird with webbed feet. Body fossils and...