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We report on sporadic fossil vertebrates from Brunei Darussalam (Borneo). Most of these isolated remains are reworked and derive from Penanjong Beach known for former coastal cliffs used to be rich...

Tanystropheus and other possible archosauromorph fossils have been discovered from Middle to Upper Triassic shallow marine sedimentary sections in Villany (Villany Hills, southern Hungary). Four fragmentary cervical vertebrae can be assigned to Tanystropheus sp. based on characteristic features including the strongly elongate and hollow vertebral body with extremely reduced neural spine. Besides the cervicals, various teeth, classified into four different morphotypes including longitudinally striated, carinated and ziphodont ones, are thought to belong to archosauromorphs, since they markedly differ from the frequently found teeth of fish and sauropterygians. In addition, three enigmatic cranial bones that might represent some circumorbital elements, have been found as well, and are referred to here as Sauropsida indet. These fossils, originated from the same tectonic unit as those from the Anisian of Bihor (Romania), are of great importance for a better understanding of the poorly known semi-aquatic to terrestrial vertebrate fauna of the Middle to Late Triassic of central Europe.

Ipolytarnóc is one of the most important Cenozoic fossil trackway sites in Europe. Most of the discovered footprints were investigated in 1985; however, a considerable period has elapsed since those investigations, and during that time significant advances have been made in the field of 3D imaging. Given this fact, the present study was undertaken to carry out a new analysis of the Ipolytarnóc fossil tracks, with a view to present possible revisions of current knowledge. In line with this, detailed ichnotaxonomical analyses were conducted on two large-sized pentadactyl footprint types using high-quality 3D models. As a result of the investigations presented in this paper, the largest pentadactyl footprint-type (previously defined as Bestiopeda maxima) was reclassified under the Platykopus ichnogenus based on new materials and their 3D models. The P. maxima footprints are believed to represent those of large-sized Amphicyonidae. Thorough ichnotaxonomical analyses were performed on other pentadactyl fossil tracks which had been attributed to Carnivoripeda nogradensis. The aim of the analyses was to suggest an extension of the morphological characters of these ichnospecies. In contrast to the previously suggested Nimravidae origin, we rather suggest that the C. nogradensis footprints belong to a mustelid-like carnivore based on its footprint morphology.

Two sites in the Villany Hills, Hungary, have yielded rich fish assemblages from Middle to Late Triassic shallow marine deposits. The collected material comes from the Ladinian Templomhegy Dolomite Member and from the Carnian Meszhegy Sandstone Formation. The ichthyofauna is composed of both chondrichthyans (Hybodontidae indet., Palaeobates angustissimus, ‘Polyacrodus’ sp., ?Lissodus sp.) and osteichthyans (Gyrolepis sp., Birgeria sp., and further indeterminate actinopterygians). Despite the large sample size, no remains of neoselachians have been found. The Ladinian Templomhegy Dolomite is dominated by durophagous hybodontiforms (Palaeobates angustissimus, ?Lissodus sp.), but the piscivorous hybodontid and the generalist ‘Polyacrodus’ sp. are missing, while in the fish fauna collected from the Carnian Meszhegy Formation indeterminate piscivorous hybodontids are the most common elements and durophagous forms are much less abundant. The dominance of piscivorous hybodontids in the Carnian Meszhegy Sandstone could be related to the global decrease of diversity of marine fish-eating reptiles (e.g., nothosaurs) or to a change of paleoenvironmental conditions. The present study improves our knowledge on the poorly known Triassic vertebrate faunas of the Tisza Mega-unit, which formed a segment of the passive Neotethys margin of the European Plate and shows an important example of a potential vertebrate faunal shift during the Middle to Late Triassic.

The Turonian–Coniacian continental fossil record in Europe is scarce. Here we present a new fossil assemblage of early Coniacian age that was systematically collected from the coal-bearing Gosau Group of the Tiefengraben locality near St. Wolfgang, Austria. The diverse assemblage is composed of at least 60 taxa including sporomorphs and Normapolles-related pollen, seeds and leaves of angiosperms and gymnosperms, charophytes, gastropods, bivalves, ostracods, termites, fishes, crocodiles and dinosaurs. Concerning charophytes, ostracods, gastropods, crocodiles and dinosaurs, the discovered specimens either extend the temporal and spatial range of specific groups (in some cases as possible relict forms) or suggest the occurrence of new taxa. The discovered remains of algae, molluscs, ostracods, calcareous nannofossils and lepisosteid fish represent a mixed faunal assemblage from different palaeohabitats, from marginal marine to low salinity and freshwater or terrestrial environments. As Normapolles-related angiosperm plants dominate the flora with a relatively high number of dentate leaves, a slightly cooler microenvironment compared to other Turonian–Coniacian Central European localities is indicated. The characteristically grooved crocodylian teeth of Tiefengraben differ from the previously known Upper Cretaceous European crocodyliform teeth and suggest a more diverse crocodyliform fauna in the region. Dinosaurs are represented by teeth of at least three different theropods, the largest of which is referred here to as basal tetanurans. The fossil assemblage of this early Gosau Group occurrence is of great importance for our understanding of the continental floristic and faunistic composition of the western Tethyan archipelago during the Cenomanian–Campanian gap.

The Somssich Hill 2 site (Villany Mts., South Hungary) yielded one of the richest late Early Pleistocene vertebrate assemblages within the Carpathian Basin. The present paper provides a summary of all former and new taxonomical results, as well as biostratigraphical and palaeoecological conclusions, which is completed with previously unpublished sedimentological and taphonomical observations on the locality. The bulk of the fauna can be referred to the Mimomys savini–Mimomys pusillus Biozone in the Biharian (MQ1), whereas a few specimens suggest an older age, namely the Mimomys pliocaenicus Biozone in the late Villanyian (MN17). The bones were affected by only a short-distance aquatic transport, thus they represent a parautochtonous and relatively unaltered assemblage. Consequently, the material was considered here as a reliable base for reconstructing the direct palaeoenvironment of the cavity. The entire section was divided here to five different palaeoecological units based on the small vertebrate fauna.

A new carnivoran fauna composed of rare dental and long bone remains of basal arctoid carnivores from upper Oligocene lagoon deposits of Hungary are described. Despite the small sample size, four separate taxa could be identified including the semi-aquatic basal mustelid Potamotherium valletoni, the small-sized, terrestrial basal mustelidan Amphictis sp. or Franconictis sp., another indeterminate basal mustelidan, and the medium-sized, terrestrial basal ursoid Pachycynodon boriei. These or related taxa are typically known from the Oligocene–early Miocene of Western Europe and for a much lesser extent from Eastern Asia or North America. The new Hungarian occurrence provides the first record of Oligocene carnivorans from geographically intermediate coeval localities in Eastern Europe. These remains will aid biostratigraphic correlation of the terrestrial Oligo-Miocene of Western Europe with the marine Paratethys region.

At the beginning of the 20th century, the Croatian-Hungarian palaeontologist Ottokar Kadic discovered a rich Late Cretaceous vertebrate assemblage around Valioara in the Haţeg Basin, including fossils of several dinosaurs and the proposed lectotype of the iconic basal eusuchian crocodyliform Allodaposuchus. These fossils were collected from seven main localities and have been housed in the collections of the Mining and Geological Survey of Hungary. However, the collection was mixed after World War II, and this unprovenanced material currently cannot be used for palaeoecological investigations. Nevertheless, the map marking the location of Kadic’s sites has been recently uncovered, showing the positions of the fossiliferous localities, which allows matching these with the historically collected specimens using geochemistry. Based on Kadic’s map, we georeferenced, relocated, and re-excavated these vertebrate-bearing outcrops, and documented their sedimentological context. Detailed stratigraphical investigations of the exposed successions indicate that this Valioara material represents one of the oldest (= earliest Maastrichtian) Late Cretaceous faunal assemblages known from the Haţeg Basin. The vertebrate remains collected during our new excavations around Valioara represent turtles (including Kallokibotion), crocodyliforms (Allodaposuchus, Doratodon, ‘Theriosuchus’, Acynodon), dinosaurs (Zalmoxes, Telmatosaurus, titanosaurs, theropods), and mammals. In order to determine potential geochemical differences among the sites, we selected several specimens with recorded stratigraphic position, measured their trace element compositions, and used these as independent proxies to assess the probable stratigraphic origin of the historical vertebrate fossils. Our detailed sedimentological, geochemical and palaeontological investigations around Valioara contribute to a deeper understanding of the distribution, evolution and palaeoecology of the Haţeg vertebrate faunas during the latest Cretaceous.

A rich and diverse ichthyofauna is described from the upper Oligocene (Egerian) sands of Mariahalom, Hungary. The site is dominated by brackish molluscs that are preserved together with rare marine and terrestrial vertebrates. Based on the isolated elasmobranch and bony fish remains, eight sharks, four rays and seven teleost taxa were identified from Mariahalom. The ichthyofauna represents a nearshore marine subtropical community dominated by odontaspidid and carcharhinid sharks and by euryhaline durophagous sparids and by sciaenid teleost fishes. Epibenthic feeders were common, whereas piscivorous taxa included barracudas, billfishes and numerous sharks, including the macropredatory Otodus angustidens. Palaeontological, sedimentological and stratigraphical data indicates a tide-influenced and fluvial-influenced nearshore palaeoenvironment with brackish lagoons and normal marine littoral habitats. The remains of terrestrial, brackish and nearshore marine invertebrates and vertebrates accumulated in a tidal channel. The systematics of the ichthyofauna is consistent with the palaeogeography inferred from invertebrates, i.e. a Central Paratethys connected to the Mediterranean area during the Egerian.

More than 2600 coprolites produced by vertebrates have been found in the fluvial lacustrine beds of the Upper Cretaceous (Santonian) Csehbanya Formation, Iharkut, western Hungary. In this study the mineral components, embedded dietary residues of these coprolites were examined and their ecological significance are discussed. The coprolite assemblage, containing mostly small-sized (length between 0.8 and 8.6 cm) specimens, can be ordered into seven different morphotypes, among which the spiral ones might have been produced by fish with spiral intestinal valves. The surface of the coprolites is mostly smooth and desiccation cracks were observed in only one case, suggesting that most of these coprolites were buried in-situ without long-term subaerial exposure. The fine-grained matrix of coprolites contains small holes, partially digested plant and animal residues but no sedimentary particles. CT-scanning was an effective method for revealing embedded dietary residues despite that the coprolites contain a large amount of pyrite. The coprolites contain cuticle remains, coalified seeds, pollen grains and diatoms. Animal residues may be the evidence of predation: mollusk shell and bone fragments, ganoid scales of Lepisosteiformes fish were frequent and one Pycnodontiformes fish tooth was found as well. It is not possible to ascertain the real producer of the coprolites, but, according to these remains, the Lepisosteiformes and Pycnodontiformes fish were included in the producer's prey. Not only the bone- but also the plant-bearing coprolites are highly phosphatic with mineral apatite in their matrix. However, the embedding fluvial sediment has significantly different chemical composition. The high phosphatic content of coprolites and the apatite might be derived from the carnivorous diet. Plant remains in the phosphatic coprolites may imply an omnivore producer or were the result of their incidental ingestion. Rapid burial and the mineral content of the animal nutriment might have been the responsible factors for the good preservation of the excrements.

The Tustea vertebrate locality, at Oltoane Hill (northwestern part of the Hațeg Basin, Romania), has provided a rich and diverse assemblage of Late Cretaceous (Maastrichtian) continental vertebrates. More than 800 vertebrate fossils were recovered from this locality; the isolated and associated remains represent 21 different taxa including amphibians, turtles, lizards, snakes, crocodyliforms, pterosaurs, dinosaurs and mammals. The local assemblage is overwhelmingly dominated by dinosaurs, with the rhabdodontid Zalmoxes as the most abundant taxon. The bonebeds that yielded this fossil material occur in a stacked series of mudstone/calcrete units belonging to the middle member of the Densus-Ciula Formation. The taphonomical investigations suggest that the Tustea assemblage is made up of attritionally accumulated politaxic remains and that it is a parautochthonous assemblage with no evidence for significant bone transport or reworking. According to the synthesis of all available field data two outstanding fossiliferous levels can be identified within the Tustea locality, where Megaloolithus eggs and hadrosauroid hatchling material are preserved together, recognized here as two superposed nesting grounds. Such co-occurrence was considered controversial, since there is a long-standing and quasi-general consensus that eggs of the Megaloolithus oogenus were laid by titanosaurian sauropods. We present several alternative scenarios to account for the co-occurrence of Telmatosaurus hatchling remains and megaloolithid eggs in the nesting horizons and explore these alternative hypotheses by weighing the arguments supporting or contradicting them. The burden of evidence derived from our sedimentological, taphonomical and palaeoecological investigations at Tustea is still in favour of the autochthony of the hatchlings, preserved within their own nesting grounds, whereas there is no such support for a titanosaurian origin of the Tuștea megaloolithid eggs.

Ankylosaurian fossils are usually standard elements of Cretaceous continental vertebrate localities; however, bone-yielding horizons including more than one individual are extremely rare. Here, we present a unique assemblage of 12 partial, articulated or associated ankylosaurian skeletons and thousands of isolated bones and teeth discovered from the Santonian Iharkut vertebrate locality, western Hungary. Collected from an area of 600 m2 and from a single bone bed, this material is one of the richest ankylosaurian accumulation worldwide. The 12 skeletons are not monospecific but mostly based on the pelvic armour composition: six of them are from Hungarosaurus, two are referred to Struthiosaurus and four can be assigned to Nodosauridae indet. Sedimentological and taphonomical examinations revealed a single mass mortality event as the cause of the death and accumulation of these quadruped animals that are described here. The ankylosaur assemblage from Iharkut suggests at least a temporarily gregarious behaviour of these animals and also shows that Hungarosaurus and Struthiosaurus might live in the same moist habitat or at least preferred relatively close environments.

There are two Triassic vertebrate sites in Villány Hills (Southern Hungary), where productive and continuous excavations have been carried out in the last six years resulting in a rich and diversified assemblage of shallow marine to coastal animals. The studied formations belong to the Villány–Bihor Unit of the Tisza Megaunit, which was located at the passive margin of the European Plate during the Triassic. The relatively diverse vertebrate assemblage was collected from a Road-cut on Templom Hill and a newly discovered site at a construction zone located on the Somssich Hill. Four main lithofacies were identified and interpreted in the newly discovered Construction vertebrate site consisting of dolomite (deposited in a shallow, restricted lagoon environment), dolomarl (shallow marine sediments with enhanced terrigenous input), reddish silty claystone (paleosol) and sandstone (terrigenous provenance) indicating that the sediments of the Construction vertebrate site were formed in a subtidal to peritidal zone of the inner ramp environment, where the main controlling factor of the alternating sedimentation was the climate change. However, the recurring paleosol formation in the middle part of the section also indicates a rapid sea-level fall when the marine sediments were repeatedly exposed to subaerial conditions. In the Road-cut site the siliciclastic sediments of the Mészhegy Sandstone Formation are exposed, representing a nearshore, shallow marine environment characterized by high siliciclastic input from the mainland.

Gregarious behaviour of large bodied herbivorous dinosaurs, such as ceratopsians, hadrosaurs and sauropods, has received much attention due to their iconic mass death assemblages (MDAs). Yet, social lifestyle of ankylosaurs, a highly specialized group of armoured herbivores that flourished predominantly during the Cretaceous Period, remains largely ambiguous. Whereas most ankylosaurs are found as isolated individuals, which may suggest a dominantly solitary lifestyle, the few examples of ankylosaur MDAs indicate that some members of this clade could have been gregarious. In this review, we assess taphonomic history, ontogenetic composition of the MDAs, defence system and other comparative anatomical attributes, and inferred habitat characteristics of ankylosaurs; aspects that may indicate and/or influence group formation in extant herbivores and can also be studied in fossils. We show that the ankylosaurian gross anatomy, such as their heavy armour, barrel-shaped body and usually stocky limbs, combined with the rarity of their MDAs and multiple parallel trackways, all suggest a solitary adult life with efficient anti-predator defence system, limited agility, and confined foraging range. However, characteristics of the known MDAs of Pinacosaurus, Gastonia, and the Iharkut nodosaurids evaluated in this study imply that at least some ankylosaurs formed groups. Nevertheless, we found no common and consistent set of features to explain why these particular ankylosaurs were gregarious. While inefficient anti-predator defence along with likely higher agility of juvenile Pinacosaurus living in open habitats could account for their gregarious behaviour, such ontogenetic, anatomical and habitat features are not combined either in Gastonia or in the Iharkut nodosaurid MDAs. Instead, members of each MDA likely had their own specific conditions driving them to form relatively small herds, indicating a more complex social structuring in ankylosaurs than previously acknowledged. Studying morphological and functional disparity within Ankylosauria may help explain the repertoire of their social behaviour. Our holistic approach shows that combining palaeontological and biological information is essential and can provide new insights into the behavioural ecology of long extinct vertebrates.

The Iharkút locality in the Bakony Mountains of western Hungary has provided a rich and diverse assemblage of Late Cretaceous vertebrates. Here we present two specimens of this assemblage, a plate fragment of the bothremydid turtle Foxemys trabanti, and a partial skull roof of the hylaeochampsid crocodilian, Iharkutosuchus makadii, that exhibit pathological traits, such as shallow and deep pits, bisected pits, and scores on their surface, and in the case of the skull roof, also a hole piercing through the entire bone thickness. Morphological and bone histological features of these pathological traits imply that they probably represent bite marks rather than deformations due to pre-mortem shell diseases, infections or post-mortem invertebrate bioerosion, and microbial activity. Morphological similarities with experimentally investigated crocodilian tooth marks suggest that both elements bear the bite marks of a crocodilian predator with typical conical teeth, possibly the Allodaposuchus-like crocodile, also known from the locality. The inferred tooth marks on the dorsal surface of the Iharkutosuchus skull roof indicate a rarely documented predator-prey interaction between two different crocodilian taxa rather than antagonistic behaviour over common resources. Nevertheless, more comparative studies are needed on different traumatic as well as non-traumatic bone pathologies that may eventuate in bite-mark-like abnormalities. © 2014.

Remains of Triassic vertebrates discovered in the Villany Hills (SW Hungary) are described here. After the well-documented Late Cretaceous Iharkut locality, this material represents the second systematically collected assemblage of Mesozoic vertebrates from Hungary. Fossils were collected from both the classical abandoned road-cut at Templom Hill (Templom-hegy) and a newly discovered site at a construction zone located 200 meters west of the road-cut. Macrofossils of the construction site are mainly isolated bones and teeth of nothosaurs from the Templomhegy Dolomite, including a fragmentary mandible referred to as Nothosaurus sp. and placodont teeth tentatively assigned here to cf. Cyamodus sp. Affinities of these fossils suggest a Middle Triassic (Ladinian) age of these shallow marine deposits. New palynological data prove for the first time a Late Triassic (Carnian) age of the lower part of the Meszhegy Sandstone Formation. Vertebrate remains discovered in this formation clearly represent a ty...

The Csehbanya Formation (Santonian), exposed in the Iharkut open-pit, Bakony Mountains, Hungary, is made up of a cyclic alternation of conglomerate, sandstone, and variegated siltstone and clay deposited in a fluviolacustrine environment. As a result of continuous excavation since 2002 it has yielded rich and diverse continental vertebrate and plant assemblages. A facies and architectural analysis of the Csehbanya Formation at this location identified four main lithofacies associations with eight subtypes consisting of (1) lenticular sandstones representing river channels, (2) conglomerates with sandstone (coarse grained likewise representing channel deposits), (3) heterolithic-channel fill (high density flash flow deposits) (4) splay sandstones produced by crevasse splays, (5) dark sandy siltstone (small-scale stagnant pool deposits with high organic content), (6) greenish-grey claystone (deposits of shallow lakes and ponds), (7) reddish (moderately drained) paleosols, and (8) yellowish, mottled (hydromorphic) paleosols. The sedimentological investigations revealed that the terrestrial deposits exposed by the Iharkut open-pit were formed in an anastomosing fluvial system because: (i) the alluvial architecture is characterized by large proportion of overbank deposits encasing the channel sandstone bodies, (ii) the ribbon shaped sandstone bodies are dominant, (iii) cross-bedding and lateral accretion are almost completely absent in the channel fill deposits and (iv) the sandstone bodies are clearly isolated from each other, embedded in floodplain sediments, suggesting multiple co-existing channels. The most important vertebrate fossil site (SZ-6) was examined in special detail because it shows peculiar lithological features. The layers richest in fossils (Unit 1) of SZ-6 site are interpreted as a lag deposit formed during an episodic high density flash flood event representing a relatively short time interval, i.e., probably within a single rainy season.

The continental deposits of the Upper Cretaceous (Santonian) Csehbánya Formation of the Bakony Mountains in Hungary yielded abundant remains of a bothremydid side-necked turtle, which are attributed to a new species of the genus Foxemys, Foxemys trabanti. F. trabanti shows strong affinities with the European monophyletic group Foxemydina owing to the absence of pits in the upper and lower triturating surfaces, the exclusion of the jugal from the triturating surface, the separation of the Eustachian tube and the stapes by a narrow fissure, the presence of deep and narrow fossa pterygoidei, the partially closed foramen jugulare posterius and the pentagonal shape of the basisphenoid in ventral view. Among the Foxemydina the bothremydid from Iharkút is more closely related to F. mechinorum than to Polysternon provinciale from the Early Campanian of France, mainly because of the position of the occipital condyle relative to the mandibular condyles of the quadrate. The new remains represent the only record of the Foxemydina outside of Western Europe and provide the earliest known occurrence of this endemic, freshwater group in the former Mediterranean Basin. The historical biogeography of the tribe Bothremydini is investigated and a hypothesis of migration from Africa to North America via the high-latitude Thulean route is put forward.

Isolated theropod dinosaur tracks were first collected in Hungary from Hettangian (Lower Jurassic) beds of the Mecsek Coal Formation in 1966 and described as Komlosaurus carbonis Kordos, 1983. Our study is based on newly collected material from additional track-bearing beds. The description of the two largest preserved surfaces containing a total of 102 tracks that can be referred to as 21 trackways is provided here. This represents the first attempt to measure, map and compare the tracks of these bipedal, functionally tridactyl dinosaurs in several associated trackways. Significant morphological variability can be observed (e.g., depth, presence or absence of a metatarsal impression, digit length, digit divarication angle) that is explained by differences in physical parameters of the substrate. The mean of pes length is 16.3 cm in tracksite PB1 and 19.9 cm in tracksite PB2. Stride length of trackways usually ranges between 120 and 170 cm; pace angulation is 160–175°. The speed of the trackmaker is calcu...

The Iharkut vertebrate locality, an open-pit mine in the Bakony Mountains (western Hungary), has provided a rich and diverse assemblage of Late Cretaceous (Santonian) continental vertebrates. The isolated and associated remains represent 31 different taxa including fish, amphibians, turtles, lizards, pterosaurs, crocodilians, non-avian dinosaurs and birds. Sedimentologic investigations suggest that the Iharkut depositional environment was represented by the floodplain of a very low-gradient river. The 10–50 cm thick bonebed of site SZ-6, is the most important fossiliferous layer in the open-pit mine and analysis of this site indicates alternating energy conditions during the bone accumulation, which resulted in fossils of different states of preservation being deposited together. The vertebrate assemblage of site SZ-6 includes three main different subsets with widely different taphonomic history. The characteristics and the preservation mode (high rate of abrasion and the spherical shape) of the “bone pebbles” suggest that this type of the isolated bones was more exposed to abrasion and probably the remains were transported from farther away than the other isolated bones. The second group includes 88% of the Iharkut collection, containing most of the identified isolated bones and teeth, and represents polytypic attritional remains transported and deposited by high density flow during ephemeral flood events. Meanwhile the monospecific ankylosaur skeletal material from Iharkut site SZ-6 may represent a mass death assemblage because seven skeletons of Hungarosaurus were discovered from an area of approximately 400 m 2 and in many cases close to each other in the same layer. The Iharkut vertebrate assemblage is dominated by bones of aquatic/semi-aquatic animals, while the number of terrestrial animal remains is subordinate. The taphonomic analysis of the ankylosaur material from Iharkut locality further strengthens the previously suggested hypothesis that some of the ankylosaurs preferred wetland habitats (e.g. areas along fluvial systems) while the other two herbivorous dinosaur groups from Iharkut (ornithopods and ceratopsians) were probably living in distal habitats.

As a result of several years of screen-washing activity, a remarkable assemblage of eggshell fragments has been recovered from the Late Cretaceous vertebrate locality of Iharkut, Hungary. Detailed investigation of the assemblage by multiple visualization techniques (scanning electron microscopy, polarizing light microscopy, X-ray micro-computed tomography), quantitative morphometric analyses, and micro X-ray fluorescence spectrometry revealed a diverse composition of five different eggshell morphotypes (MT I–MT V) and three subcategories within the second morphotype (MT II/a, b, c), with MT I being by far the most abundant (83%) in the assemblage. MT I, MT III, and MT V represent theropod dinosaurian eggshells, whereas MT II and MT IV show characteristics of crocodilian and squamate eggshells, respectively. Hence, despite their fragmentary nature, these eggshells represent the first clear evidence that various sauropsid taxa had nesting sites near the ancient fluvial system of Iharkut. Besides the implied...