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The Upper Cretaceous Cantwell Formation in Denali National Park and Preserve (DENA) preserves an abundant and diverse ichnofossil record of high latitude dinosaurs. Field-based investigations of the formation remain limited due to its wide areal extent and remoteness, leaving questions concerning its temporal and faunistic relationships to other units unaddressed. Here we describe the largest tracksite known in DENA and all of Alaska – a 7500 square metre outcrop of steeply dipping beds known as the Coliseum. The site exposes 66.3 metres of vertical section consisting of laterally extensive fine- to medium-grained sandstone, mudstone, calcareous shale, and bentonite. Vertebrate trace fossils include true tracks, transmitted tracks, natural casts, and trackways documented via handheld and UAV-assisted photogrammetry, enabling three-dimensional mapping of the site. Facies analysis reveals a depositional environment of crevasse splay and overbank deposits within a fluvial floodplain. U-Pb dating of bentonite collected from the site returned an age of 69.3 ± 0.9 Ma, improving the limited temporal constraints of the formation. We document several ichnotaxa, some new to the formation, representing ornithopods, ceratopsids, and large and small-bodied avian and non-avian theropods. The Coliseum provides a rare window into a high latitude, Late Cretaceous forested ecosystem deposited in a Greenhouse World. [ABSTRACT FROM AUTHOR]

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The Coniacian-Santonian stages in western North America are characterized by a sparse fossil record. We present here the first account of dinosaur tracks from nine sites in the Frontier Formation (Coniacian-Santonian) of southwestern Montana. Tracks are largely preserved in distal alluvial facies as sandstone casts, with a single example of shallow epirelief impression interpreted as undertrack. Sandstone casts show significant relief, kinematic features (i.e., scale marks), and variable morphologies, arguing for a strong substrate control on their preservation. Putative producers are assigned to ornithopod, ankylosaurian, and theropod dinosaurs in decreasing order of abundance. This record reflects a composition similar to those of other middle Cretaceous formations in North America. Moreover, ankylosaurian tracks of the Frontier Formation represent the first known from Coniacian strata in North America. The incorporation of body and trace fossils yielded by the Frontier Formation indicates the presence of a fauna with North American endemic elements. The establishment of Coniacian-Santonian dinosaurian palaeocommunities akin to those observed in Campanian and Maastrichtian formations may reflect the trend towards provincialism attested for the end of the Mesozoic in North America. [ABSTRACT FROM AUTHOR]

The Regional Natural Park (RNP) of the Monts d'Ardèche, located in south-eastern France, became the Monts d’Ardèche UNESCO Global Geopark in September 2014. This territory possesses significant geological structures, including numerous and rich Middle-Late Triassic vertebrate tracksites. The UNESCO Global Geopark label helped to formalize a long-standing partnership for the study of this ichnological patrimony between the RNP of the Monts d'Ardèche and the University of Burgundy. Developing scientific research, protection, training and outreach are the main lines of the agreement signed in 2015. The strategy is to make a detailed and sedimentologically contextualized inventory of vertebrate tracks in the Geopark and its surroundings, establish conservation and protection priorities, set up geosites for the public and involve local people in all these activities. To date, 15 tracksites and nearly a thousand individual tracks have been inventoried. The locality “Le Sartre” stands out as being the first recognized geosite amongst the remarkable tracksites in Ardèche. After four years of scientific investigations and fitting out works, it was inaugurated in October 2020. This geosite is the first equipped locality in France to show Late Triassic dinosaur tracks and to be freely accessible to the public. This success was made possible by the intellectual, logistic and social involvement of local people throughout, by acknowledgement of these contributions, and by the capacity of all actors to collaborate efficiently with each other. With more than 1000 fossil vertebrate tracks still awaiting to be valorized in Ardèche, the designation as a UNESCO Global Geopark clearly marked a turning point from academic-only to articulated research, conservation and geotouristic initiatives involving local communities.

The low level of the Jurassic sea in the area of Bad Essen-Barkhausen (Wiehen Mountains, NW Germany) was a precondition for the migration of a herd of sauropods and theropods through this coastal area about 153 million years ago. The dinosaurs left at least 11 trackways on a single fine-grained siltstone layer and several more footprints on another, younger layer. The dinosaur track layers experienced diagenesis and subsequent uplifting during the Late Cretaceous, so that they are presently exposed in sub-vertical position on a quarry rock wall. Since the discovery of the tracks in 1921, their preservation has been challenging. It has not been possible to recover the tracks because of dense jointing in the host rocks, so an in-situ fossil geosite had to be established. Because in-situ geoconservation was not common practice until the 1960s, the dinosaur tracks were initially conserved only as casts. Since the 1960s, the geosite has undergone regular protection measures, including impregnation, cement slurry injections, a drainage system and construction of a glass roof. In 1976, the quarry was granted the status of an open-air museum, which currently offers regularly updated panels, life-sized dinosaur models, guided tours, events, exhibitions and an anchor point in a hiking and cycling trail network. The conservation of the dinosaur track layers and the continuous improvement of touristic and educational programs have only been possible through decades of collaboration between the UNESCO Global Geopark TERRA.vita and its partners such as Osnabrück County, the City of Bad Essen, the Natural History Museum “Museum am Schölerberg” in Osnabrück, the Experiential Pedagogical Country Hostel Barkhausen and local associations.

Two sandstone slabs from a new Norian tetrapod tracksite in the Löwenstein Formation of southern Germany preserve a set of tracks including both tridactyl and pentadactyl ichnites, referred to theropod dinosaur and sphenosuchian crocodylomorph trackmakers, respectively. A very large manus print hints at the presence of a hitherto unknown large quadrupedal archosaur in the Norian fauna of southern Germany. The material includes one of the oldest records of crocodylomorph tracks presently known, in agreement with the skeletal record from the same formation. [ABSTRACT FROM AUTHOR]

The Coniacian non-marine portion of the Frontier Formation in southwestern Montana has been primarily studied stratigraphically, whereas its trace fossil record and relative sedimentological significance have remained overlooked so far. We present the first description of a trace fossil assemblage reported from Frontier Formation deposits exposed in the western Centennial Mountains, Beaverhead County, Montana. Three main lithofacies groups with distinctive trace fossil assemblages have been recognised at the locality of Price Creek: (1) coarse-grained, thin and laterally extensive cross-bedded sandstone channel bodies characterised by rare vertical, passively filled burrows; (2) fine-grained overbank sandstones and siltstones, with abundant horizontal, meniscated, and unwalled burrows, sinusoidal trails, vertical burrows, and dinosaur tracks, and (3) fining-upward, planar cross-bedded silty sandstones, associated with carbonaceous plant material and bone fragments. The trace fossil assemblage is ascribed to the pre-desiccation suit of the Scoyenia ichnofacies. The occurrence of theropod, ornithopod, and thyreophoran dinosaur tracks, and invertebrate trace fossils suggests considerable diversity of terrestrial and aquatic fauna. Tracks described here represent the first dinosaurian record reported from Coniacian deposits in Montana and one of the few fossil records reported from non-marine Coniacian deposits in North America. [ABSTRACT FROM AUTHOR]

Dinosaur tracks associated with coal-mines of the Middle to Upper Jurassic (Callovian–Tithonian) Walloon Coal Measures (Clarence–Morton Basin) have been reported on more than any other track-bearing formation in Australia, yet due to the brevity of ichnological information, remain poorly known. All these tracks were found in sediments directly above coal seams in the ceilings of subterranean mines. This style of mining ceased more than a quarter of a century ago, and with many of the original mines having been back-filled or closed, ichnological investigations are restricted to the study of museum specimens and archival photographs. Here, we consolidate data from the literature, present previously unpublished archival photographs, and show the 3D topography of all accessioned track specimens from the Walloon Coal Measures. We recognise eleven track-bearing sites, most of which produced large (length of 30–50 cm) and very large (length greater than 50 cm) sized theropod tracks, including Australia's largest carnivorous dinosaur footprint (79 cm long). The domination of theropod tracks is unique among Australian dinosaur tracksites. In light of the absence of near coveal body-fossil candidates, the Walloon Coal Measures ichnofaunal assemblages fills significant gaps in our understanding of Australia's Jurassic dinosaur fauna. [ABSTRACT FROM AUTHOR]

The ichnological and palaeobiological interpretation of the first dinosaur tracks described from the Lower Jurassic (Sinemurian) Razorback beds, anthropogenic 'fireclay caverns' of Mount Morgan, Australia, is reviewed. This track sequence of two size categories has been widely accepted as having been formed by a theropod walking in an uncharacteristic quadrupedal stance. However, the morphology of the purported manus impression remained ambiguous due to the poor reproduction quality of the original image data. Here, we present previously unpublished archival photographic and replica material of this track surface. These clearly show the morphological details of the track series that are consistent with registration by two different sized bipedal track-makers. Overall, our findings illustrate that retained archival data can be pivotal in the resolution of palaeoichnological obscurities. [ABSTRACT FROM AUTHOR]

This study focuses on the analysis of the first dinosaur tracks discovered in the Mulichinco Formation, Neuquén Basin, Argentina. The deposition of this unit occurred during the early Valanginian, Early Cretaceous, making it the oldest known record of dinosaur tracks for that period in the basin. The aim of this study is to provide a paleoenvironmental interpretation of the area and potential trackmakers based on the morphology of the tracks and the facies analysis of the depositional system. The depositional system evolved from a moderately sinuous fluvial system in the lower interval to a braid distal plain system with the development of bodies of water without marine influence, culminating in an estuary with marine influence in the upper interval. The paleoenvironmental conditions during the deposition of the unit were favourable for the presence and interaction of diversity large continental vertebrates. The track-bearing surfaces in the lower interval suggest that the organisms exploited the temporary gaps created between channel migration and floodplain formation as areas for transit or water sources. In the middle interval, the abundant presence of traces fossils of invertebrates and symmetrical ripples suggest a more stable depositional system where fluctuations in the water column were common. The co-occurrence of various track-makers and remains of large vertebrates described in the Mulichinco Formation is unusual among track sites at the basin. Overall, this study provides new insights into the Early Cretaceous paleoenvironmental conditions of the Neuquén Basin and the diversity of large vertebrates that inhabited the region during this time. • The first analysis of dinosaur footprint-bearing surfaces from the Valanginian of the Neuquén Basin is presented. • The great abundance of footprint-bearing levels suggests high diversity of continental vertebrates. • The dinosaur footprints on different surfaces adjust interpretation of depositional dynamics. [ABSTRACT FROM AUTHOR]

Abstract A new Middle Jurassic tracksite dominated by non-avian theropod footprints from the Wangjiashan Formation in Pingchuan District, Baojishan Basin, Gansu Province has yielded a unique trackway with four consecutive manus-pes sets. Only three previous examples, all Early Jurassic in age, of theropod trackways are known with convincing examples of manus tracks and in each case, only two tracks were recorded in association with pes tracks with metatarsal impressions and pelvic traces indicating crouching behavior. Thus, this is the first example of manus tracks registered while a theropod trackmaker was walking. This unique configuration is here designated as Grallator pingchuanensis ichnosp. nov. which shows the trackmaker forelimbs registering in a wide straddle gait, much wider than the pes trackway width. G. pingchuanensis confirms previous reports that theropods could occasionally register tridactyl, ectaxonic manus traces. In the case of the Pingchuan trackway, the short step indicates an animal moving at a slow speed, probably due to a soft substrate.

Although underground dinosaur tracksites inside anthropic cavities such as mines or tunnels are well-known throughout the world, footprints inside natural karstic caves remain extremely rare. The Malaval Cave (Lozère, southern France) is well-known by speleologists for the abundance and the exceptional quality of acicular and helictite aragonite speleothems. Recent palaeontological prospecting inside this cave allowed the discovery of tridactyl dinosaur tracks. Here, a detailed study of theropod footprints was for the first time conducted inside a natural karstic cave, using photogrammetric imaging technique. Tracks from the Malaval Cave are located inside the “Super-Blanches” galleries. More than 26 footprints were identified. They are Hettangian in age (Lower Jurassic) and preserved as both in situ convex hyporeliefs and ex situ concave epireliefs. Tree morphotypes are distinguished, (i) “Dilophosauripus-Kayentapus” morphotype, (ii) “Eubrontes” morphotype, and (iii) “Grallatorid” morphotype. Sedimentological and mineralogical analyses of the tracksite indicate that the depositional environment varied from periodically emergent subtidal to intertidal/supratidal flat marsh. This work highlights the great interest and importance of palaeoichnological prospecting in karst caves. This is particularly true for the Causses Basin where hundreds of natural cavities were reported by speleologists in the formations yielding dinosaur traces.

The city of Araraquara in southeastern Brazil is unique regarding its paleontological record. Flagstones have been quarried from eolianites (Botucatu Formation, Lower Cretaceous) since the beginning of the twentieth century and used to pave and cover public and private spaces of the city. As a consequence, fossil tracks and traces (ichnofossils) of invertebrates, early mammals, and dinosaurs are widely distributed in the flagstones that pave the sidewalks of the city, right under the feet of Araraquara's inhabitants. In this paper we aimed to characterize this unique fossil record, focusing on the main trace morphotypes and their conservation. In a survey conducted in 2007–2008, 585 trace fossil-bearing flagstones were identified across Araraquara, much of which are moderately to poorly preserved. Nevertheless, optimally preserved (elite) traces of very high scientific potential were also recorded. The present study also includes a history of investigations conducted regarding these materials and discusses different aspects, difficulties, and peculiarities of conservation efforts towards this urban paleontological heritage, including some recently achieved goals. [ABSTRACT FROM AUTHOR]

Earth's orbital variations on timescales of 104–105 years, known as Milankovitch cycles, have played a critical role in pacing climate change and ecosystem dynamics, through glacial and/or monsoon dynamics. However, the climatic and biotic consequences of these cycles on much longer (~ 107 years) timescales remain unclear, due to a lack of long proxy records with precise age constraints. Here, we show ~ 10-Myr scale variations in early Mesozoic (250–180 Ma) records of lake-level, desert distribution, biogenic-silica burial flux, atmospheric CO2 levels (pCO2), and sea-surface-temperature (SST). Their phase relationships, coupled with carbon cycle modeling results, suggest that orbitally-paced summer monsoon dynamics modulates changes in terrestrial weatherability by ~ 20%, affecting changes in pCO2 of up to 500–1,000 ppmv and 3–7 °C SST. We also infer that these ~ 10-Myr scale climatic variations could have been causally linked to biotic turnover, size variations in dinosaur footprints, and tetrapod dispersal, potentially through spatio-temporal variations in resource availability and arid-hot climatic barriers at low-middle latitudes. [ABSTRACT FROM AUTHOR]

The functional anatomy of the hindlimb of bipedal dinosaurs has been intensively studied. Yet, surprisingly little work has been done concerning functional adaptation of digits for terrestrial locomotion. While complete and articulated pes skeletons are scarce, pes shape is abundantly recorded by fossil footprints. We elucidate the significance of footprint shape and size for locomotion using a large sample (n = 303) of tridactyl dinosaur footprints from a broad range of geographical localities and time slots. Size and shape variation are characterized separately for theropods and ornithischians, the two principal trackmaker taxa. At smaller sizes, theropod footprints are best discriminated from ornithischian footprints by their smaller interdigital angle and larger projection of digit III; at larger sizes digital widths are effective discriminants. Ornithischian footprints increase in size from the Early Jurassic to the Late Cretaceous, a trend not observed in theropod footprints. Size and function are argued to be important determinants of footprint shape, and an attempt made to infer function from shape. Digit III projection and length‐to‐width ratio of the footprints are negatively correlated with size in both groups; digit impression width is positively correlated with size only in ornithischians. Digit III projection appears to be positively correlated with cursorial ability. Increased interdigital angles are associated with a decrease in digital width, possibly an adaptation for stability. Weak digit III projection and increased digital width are interpreted as adaptations for graviportality. Footprints yield great potential for the understanding of the functional morphology of dinosaur feet. [ABSTRACT FROM AUTHOR]

The Botucatu Formation (Paraná Basin, Brazil and the southern neighboring countries) comprises one of the richest tetrapod ichnological deposits of the Lower Cretaceous in South America. The ichnofossils are found in reddish sandstones lithofacies -interpreted to be dune and interdune deposits. The sandstones of Botucatu Formation originally covered a surface estimated in at least 1,300,000 km2, the largest known fossil desert in the Earth's history. The distribution area of the Botucatu paleodesert presents one of the world's largest megatracksites. The tetrapod ichnofauna from the Botucatu Formation comprises minor bipedal dinosaur tracks (almost all attributable to theropods, with one exception, a doubt ornithopod trackway) along with many thousands of footprints of early mammals, and a single trackway of a lacertiform reptile. Among the bipedal dinosaur footprints, the most common and typical are considered theropod tracks, with long strides and high step angle and always with an acuminate termination. These trackways are straight and very narrow, with long strides and step angles showing high values. The footprints have a relatively large and very wide III digit and small, short, pointed, bladelike outer digits. The most special characteristic is that the II digit is longer and more important than the IV digit. Because of this morphology, the general outline of the footprint often reminds that of a waterdrop and, although it is structurally tridactyl, it usually looks like functionally monodactylous. These tracks are herein assigned to small theropods adapted to desert life with a prevalently cursorial gait, probably ancestors of clades such as noasaurs and velocisaurs. Due its unique morphological aspects it is defined a new ichnogenus and ichnospecies, Farlowichnus rapidus new ichnogen., new ichnosp. [Display omitted] • Botucatu Formation comprises one of the richest ichnological deposits of Lower Cretaceous in South America. • The tetrapod ichnofauna from the Botucatu Formation comprises bipedal dinosaur tracks and numerous mammal tracks. • The new ichnospecies have a large and very wide digit III and small, short, pointed, bladelike outer digits. • The trackmakers are assigned to small theropods adapted to desert life with a prevalently cursorial manner of gait. [ABSTRACT FROM AUTHOR]

The objective definition of footprint margins poses a central problem in ichnology. The transition from the footprint to the surrounding sediment is often continuous, and the footprint wall complex, requiring interpolation, approximation, and a priori assumptions about trackmaker anatomy to arrive at feasible interpretations of footprint shapes. The degree of subjectivity of such interpretations is substantial, and outlines produced by separate researchers can differ greatly. As a consequence, statistical shape analysis, regardless if based on linear and angular measurements or on the shape as a whole, are neither fully repeatable nor objective. Here I present an algorithm implemented in the programming environment R that is able to generate continuous footprint outlines based on three-dimensional models—fully automatically, objectively, and repeatable. The approach, which is based on contour lines extracted from the model, traces the outline at the point where the slope of the track wall is steepest. An option for automatic landmark placement is implemented for tridactyl footprints. A case study was carried out on 13 footprints of a single trackway of a theropod trackmaker from the Lower Cretaceous of Münchehagen, Germany. Analysis of the landmark coordinates returned by the script did reproduce statistical results published in an earlier study that was based on human-made interpretative drawings, demonstrating the applicability of the present method for the objective and quantitative shape analysis of tracks. Although faint anatomical details are not always recorded and features not related to the foot anatomy may be included, the generated outlines tend to correspond with human-made interpretative drawings regarding the overall shape. While not suited as a full replacement of interpretative drawings, these generated outlines may be used as an objective basis for such interpretations.

The tridactyl ichnotaxon Eubrontes giganteus commonly has been attributed to a carnivorous theropod dinosaur similar to Dilophosaurus or Liliensternus. For this to be correct, however, at least five unusual circumstances all must be true. (1) If the Eubrontes track-maker was a theropod, it created the most abundant large tracks found in the Connecticut Valley Hartford and Deerfield basins and yet, for unknown reasons, left no skeletal remains there at all. This pattern also holds true for the Kayenta Formation and Navajo Sandstone in the American Southwest. (2) The cursorial, bipedal, functionally tridactyl prosauropod Anchisaurus, which left two-thirds of the skeletal remains found in these same basins, for unknown reasons left no tracks there at all. (3) If the Eubrontes track-maker was a theropod, by happenstance, it was a theropod exactly the same size as Anchisaurus. (4) If the Eubrontes track-maker was a theropod, then published evidence for herding by Eubrontes track-makers must be due to local paleogeographic factors, not recognizable in the rock record, which created an illusion of herding. (5) The known stratigraphic range of Eubrontes tracks (Norian-Toarcian) by happenstance falls entirely within the known stratigraphic range of bipedal prosauropods (upper Carnian-Toarcian). None of these unusual circumstances need be true, however, if Anchisaurus was the Eubrontes track-maker. Recent reports of an anteriorly directed hallux in the Eubrontes track-maker provide compelling evidence that prosauropods, not theropods, made Eubrontes tracks. Parsimony strongly favors this conclusion and weighs heavily against the idea that the Eubrontes track-maker was a mysterious, elusive theropod whose skeletal remains have evaded discovery for nearly two centuries. [ABSTRACT FROM AUTHOR]

The morphology of fossil footprints is the basis of vertebrate footprint ichnology. However, the processes acting during and after trace fossil registration which are responsible for the final morphology have never been precisely defined, resulting in a dearth of nomenclature. Therefore, we discuss the concepts of ichnotaphonomy, ichnostratinomy, taphonomy, biostratinomy, registration and diagenesis and describe the processes acting on footprint morphology. In order to evaluate the morphological quality of tetrapod footprints, we introduce the concept of morphological preservation, which is related to the morphological quality of footprints (M-preservation, acronym MP), and distinguish it from physical preservation (P-preservation, acronym PP), which characterizes whether or not a track is eliminated by taphonomic and diagenetic processes. M-preservation includes all the morphological features produced during and after track registration prior to its study, and may be divided into substages (ichnostratinomic, registrational, taphonomic, stratinomic, diagenetic). Moreover, we propose an updated numerical preservation scale for M-preservation. It ranges from 0.0 (worst preservation) to 3.0 (best preservation); intermediate values may be used and specific features may be indicated by letters. In vertebrate footprint ichnotaxonomy, we regard the anatomy-consistent morphology and to a lesser extent the trackway pattern as the only acceptable ichnotaxobases. Only footprints showing a good morphological preservation (grade 2.0–3.0) are useful in ichnotaxonomy, whereas ichnotaxa based on poor morphological preservation (grade 0.0–1.5) are considered ichnotaphotaxa (nomina dubia) characterized by extramorphologies. We applied the preservation scale on examples from the Palaeozoic to the present time, including three ichnotaphotaxa and 18 anatomy-consistent ichnotaxa/morphotypes attributed to several vertebrate footprint producers. Results indicate the utility, feasibility and suitability of this method for the entire vertebrate footprint record in any lithofacies, strongly recommending its use in future ichnotaxonomic studies. [ABSTRACT FROM AUTHOR]

The objective definition of footprint margins poses a central problem in ichnology. The transition from the footprint to the surrounding sediment is often continuous, and the footprint wall complex, requiring interpolation, approximation, and a priori assumptions about trackmaker anatomy to arrive at feasible interpretations of footprint shapes. The degree of subjectivity of such interpretations is substantial, and outlines produced by separate researchers can differ greatly. As a consequence, statistical shape analysis, regardless if based on linear and angular measurements or on the shape as a whole, are neither fully repeatable nor objective. Here I present an algorithm implemented in the programming environment R that is able to generate continuous footprint outlines based on three-dimensional models—fully automatically, objectively, and repeatable. The approach, which is based on contour lines extracted from the model, traces the outline at the point where the slope of the track wall is steepest. An option for automatic landmark placement is implemented for tridactyl footprints. A case study was carried out on 13 footprints of a single trackway of a theropod trackmaker from the Lower Cretaceous of Münchehagen, Germany. Analysis of the landmark coordinates returned by the script did reproduce statistical results published in an earlier study that was based on human-made interpretative drawings, demonstrating the applicability of the present method for the objective and quantitative shape analysis of tracks. Although faint anatomical details are not always recorded and features not related to the foot anatomy may be included, the generated outlines tend to correspond with human-made interpretative drawings regarding the overall shape. While not suited as a full replacement of interpretative drawings, these generated outlines may be used as an objective basis for such interpretations. [ABSTRACT FROM AUTHOR]

The Qingquan dinosaur tracksite, from the Lower Cretaceous Dasheng Group, Shandong Province, China adds to the growing record of saurischian-dominated ichnofaunas of the region. The site reveals the presence of avian theropods (Koreanaornis) and non-avian theropods tentatively referred to Jialingpus. Sauropod tracks are referred to Brontopodus. One site shows evidence of extensive trampling attributable to sauropods and theropods that moved in the same westerly direction, though not necessarily at exactly the same time. This site is reminiscent of the famous Davenport Ranch site in Texas which has provoked much debate about the herding behavior of sauropods as a defense strategy against theropod predators. [ABSTRACT FROM AUTHOR]

A new vertebrate ichnological assemblage is described from the Hettangian Dolomitic Formation of the Causses Basin, at Le Serre (Lozère, southern France). We report tracks that complement the poor fossil record of lowermost Jurassic crocodylomorphs in Europe. Tetradactyl pes and pentadactyl manus imprints form a unique trackway. Traces are ascribed to Batrachopus isp. and they represent the third occurrence of this ichnogenus in European Hettangian geological formations. This is the first report of Batrachopus in Hettangian deposits of the Causses Basin. The tracks share some similarities with Batrachopus deweyi previously described from the Sinemurian of the Causses Basin. Crocodylomorph tracks co-occur with tridactyl dinosaur traces assigned to Dilophosauripus williamsi and Grallator isp. The sedimentology and palaeoichnology of the tracksite indicate that the depositional environment was a tidal to supratidal flat marsh that was emerged periodically. The ichnological assemblage from Le Serre and a synthesis of ichnotaxa co-occurring with Batrachopus in the European lowermost Jurassic tracksites confirm that crocodylomorphs living in marginal-littoral palaeoenvironments were part of theropod-dominated faunas, together with ornithopods but apparently without sauropods. [ABSTRACT FROM AUTHOR]

Abstract The discovery of new Titanopodus trackways (Loncoche Formation, Argentina) shed light on the locomotion of titanosaur sauropods. Two patterns related with different size of trackmakers are identified based on ichnological and anatomical evidences. AC-1 and AC-4 trackways (pattern 1) are characterized by alternated manus and pes tracks. This is congruent with an asynchronous gait produced by large individuals that walked at 4.7–4.8 km/h. AC-3 trackway (pattern 2) shows some elongated and distorted tracks interpreted as overlapped manus and pes prints. This interpretation is supported by the presence of clear juxtaposed or partially overlapped manus and pes prints in some parts of the trackway. Pattern 2 is preliminary assigned to an amble gait produced by a smaller individual that walked at 3.7 km/h. These two patterns can be analyzed as different gaits in titanosaurs that walked together. [ABSTRACT FROM AUTHOR]

The earliest Cretaceous (mid-late Berriasian) tracksite Los Corrales del Pelejón is an important dinosaur trackway site in Teruel Province in Spain. The ichnoassemblage occurs in the Galve Formation (Galve sub-basin, Maestrazgo Basin) and comprises around 40 tracks assigned to theropods and ornithopods. In this paper, we undertake a paleoenvironmental analysis of the succession, which includes the overbank deposits of a fluvial environment, and discuss the implications of these findings for trackway preservation and orientation. The track-bearing unit is composed of fine- to very fine-grained, thinly bedded sandstone layers with wave ripples and traces of the Mermia ichnofacies, which were deposited as splay deposits within an ephemeral overbank pond. Two different theropod ichnotaxa (Megalosauripus cf. transjuranicus and Grallatoridae indet.) of three different size classes occur as small-, medium-, and large-sized tracks. The ornithopod tracks are classified as cf. Iguanodontipus isp. Five theropod trackways (M. cf. transjuranicus) show a bimodal orientation pattern with a similar orientation to NE-SW wave ripple crests, suggesting that these animals were walking parallel to the shoreline of the ephemeral overbank pond. Three of them walked in a similar subparallel orientation, but there is no evidence suggesting gregarious behavior as they have slightly different orientations and/or speed values. The Los Corrales del Pelejón site is an example of environmental influence on dinosaur behavior. • New data on a historic dinosaur tracksite (one of the first described in Spain). • Detailed analysis into the stratigraphy and track preservation. • Fluvial environment with splay deposits accumulated in an ephemeral pool. • New ichnotaxonomic study with large amount of 3D data. • Dinosaur trackway orientation influenced by the shoreline of the ephemeral pool. [ABSTRACT FROM AUTHOR]

Dinosaurs were abundant and diverse during the Cretaceous period, but relevant reports from the Tibet Plateau are far rare. Here, we report a new dinosaur tracksite from Zonggei Formation of continental alluvial fan in Dingqing County, which is the first discovery of Upper Cretaceous sauropod and ornithopod dinosaurs in Tibet, China. Four track layers have been found at this tracksite, three of them showing well-preserved and densely-packed dinosaur footprints. Most abundant are sauropod tracks (probably titanosaur) on a trampled area, making it impossible to distinct trackways. One clear ornithopod (probably hadrosaur) trackway is composed of eight consecutive pes, tracks permitting to analyse the gait of the trackmaker. The ichnoassemblage provides evidence for the presence of abundant dinosaurs in the Late Cretaceous of the Tibet region. • The Upper Cretaceous non-avian dinosaur tracks in Tibet is report for the first time. • The tracks can indicate the potential Late Cretaceous dinosaurs. • The gait of Hadrosauropodus isp. has been determined. • The trackmaker of Sauropod tracks indet. Morphotype 1 is probably titanosauriform. • The Sauropod tracks indet. Morphotype 2 is a new kind of footprint. [ABSTRACT FROM AUTHOR]

Two new dinosaur tracksites are reported from the Lower Cretaceous Jiaguan Formation in the Sichuan Basin, Qijiang District of Chongqing. These are the Gaoqing-Yongsheng and the Huibu tracksites, which represent the 13th and 14th reports from this formation. The Gaoqing-Yongsheng tracksite reveals the trackway of a large biped (ornithopod) in association with isolated sauropod tracks and large indeterminate undertracks with radial cracks. These features are preserved as natural casts with pebble infillings in a coarse, cross bedded and very thick bedded sandstone sequence. The Huibu tracksite reveals isolated theropod tracks and ornithopod tracks, the latter having a quadripartite, Caririchnium-like morphology, preserved in a thin bedded sandstone sequence with intercalated mudstone. [ABSTRACT FROM AUTHOR]

Lanzhou-Minhe Basin is situated on the middle Qilian orogenic belt. Yanguoxia Formation contains abundance of maroon siltstones, mudstones and red sandstones of the lake facies. These sedimentary rocks recorded the process of the tectonic uplift of Qilian Mountains during the Early Cretaceous. We discovered plentiful dinosaur footprints, worm burrows, bird footprints, worm tracks-trails, ripple marks and cross lamination in the Yanguoxia site. Integrated petrographic studies classified sandstones of Yanguoxia Formation as feldspathic litharenite. All plots in the QFL (Q or Qt, total quartz; F, feldspar; L, lithic grains) and QmFLt (Qm, monocrystalline quartz; Lt, lithic grains plus polycrystalline quartz) diagrams fall in the recycled orogen provenance field and quartzose recycled field, respectively, implying the source occurred the tectonic activity. Furthermore, geochemical study indicates that the Yanguoxia standstone was formed in an unstable continental setting due to the northwards movement of Indian Plate triggered the collision between the Qilian fold belt and the Qinling fold belt. These sediments were derived from a mixed source and then deposited in the Lanzhou-Minhe Basin. Most of the felsic components were derived from the granitoid rocks of the Qilian Mountains due to the rapid and intense uplift during the Early Cretaceous while the mafic components were contributed by the basic and ultrabasic rocks of the rapidly rising ophiolite in the Qilian Mountain area. Bivariant log-log plot of Qp/(F+L) (Qp, polycrystalline quartz) against Q/(F+L) shows that Yanguoxia Formation was deposited in the semi-humid and semi-arid. Moreover, the pollen also exhibits that the environmental condition during the deposition of Yanguoxia Formation was warm and wet, which affirm such environment was benefit to dinosaur survival. Geochemical study also infers that the Yanguoxia Formation was deposited under the oxidizing condition in a shallow marine environment. The minerals identified from the X-ray diffraction (XRD) analysis of shale and siltstone samples are 4.74%-33.53% clays, 23.45%-4l.70% carbonates and 33.99%-71.81% quartz, respectively, which infer that depositional conditions remained uniform during the formation of shales or siltstones of Yanguoxia Formation. [ABSTRACT FROM AUTHOR]

In the last decade, digital modeling techniques have been shown to be very useful in the study of fossils and their preservation, especially with ichnites (footprints) that are very difficult to collect or model by traditional methods, due to deposit characteristics such as size, heritage, touristic importance and conservation status. In Cerro del Pueblo Formation (FCdP), a geological unit of the late Campanian, located in the southeast Coahuila, Mexico, there is a great fossil diversity, mainly dinosaur ichnites, which unfortunately have been little studied and are in danger of destruction, due to the erosion and human activities. The goal of this project was testing the effectiveness of a new and low-cost technique with no impact for the ichnites. The technique consisted of modeling by digital photogrammetry through the open access software VisualSFM, Meshlab, CloudCompare and ParaView. For this purpose, the dinosaur tracks of six different sites (deposits) in FCdP were recorded. Ten commercial quality cameras (5 to 10 Mpx) were used to take photos at each site. At smaller sites with a fewer number of footprints (Cantera Rojas, 26 m2 [4 tracks]; Depósito de la Luz, 37.5 m2 [6]; La Rosa, 60 m2 [9] and Las Águilas B, 70 m2 [12]), individual shots of ichnites were taken. Also, a complete photo series throughout the deposit was taken. Larger sites (Paso del Oso, 168 m2 [107] and Las Águilas A, 340 m2 [220]) were divided into sections to simplify the photographic record. In total, 11840 photographs were taken, 4960 were used to generate 72 three-dimensional textured polygonal mesh models for the six localities. Models from smaller sites had better quality because of their reduced size, the large number of photos taken and good strata contrast. In contrast, models from bigger sites lost definition, especially after certain adjustments made to improve their computer processing. During this exercise, reference parameters were obtained, to increase the effectiveness in photography for photogrammetric processing. We hope in the future to improve the quality of digital models generated. [ABSTRACT FROM AUTHOR]

The Guará Formation (Paraná Basin, southern Brazil) is an Upper Jurassic unit that yielded a dinosaur ichnoassemblage composed of theropod, ornithopod, and sauropod tracks. A new set of footprints is described herein and its major features are heteropody, paraxony, and both manual and pedal tetradactyly, among others. Using ichnological, osteological, and stratigraphic approaches, we interpret these tracks as produced by an ankylosaur dinosaur. The record of these armored dinosaurs in South America is scarce and restricted to the Cretaceous units of Argentina, Bolivia, and Brazil. Therefore, the presence of these tracks in the Guará Formation provides the oldest evidence of ankylosaurs in western Gondwana and the first uncontroversial record of this group in Brazil. In addition, a comparison between the Guará Formation fossil record and other Kimmeridgian-Tithonian dinosaur-bearing units worldwide indicates that more efforts are needed to better understand the geographical distribution of Late Jurassic dinosaurs. [ABSTRACT FROM AUTHOR]

The Kokorkom desert extended over an area of 826 km 2 in the central-west sector of Neuquén and Río Negro provinces along the area of the backbulge basin within the Andean Foreland basin in the Neuquén Basin. Its deposits constitute the middle-upper section of the Candeleros Formation (Cenomanian) and reach approximately 130 m thick. Tracks are found on wet and dry interdune and within draa slipface deposits. They constitute biogenic deformation structures characterized by folded-up and/or brecciated sandstone levels formed under dry and/or wet substrate conditions with passive filling. The degree of preservation varies, but the identification of digit impression suggests that they were produced by theropods or iguanodontians. [ABSTRACT FROM AUTHOR]

Although underground dinosaur tracksites inside anthropic cavities such as mines or tunnels are well-known throughout the world, footprints inside natural karstic caves remain extremely rare. The Malaval Cave (Lozère, southern France) is well-known by speleologists for the abundance and the exceptional quality of acicular and helictite aragonite speleothems. Recent palaeontological prospecting inside this cave allowed the discovery of tridactyl dinosaur tracks. Here, a detailed study of theropod footprints was for the first time conducted inside a natural karstic cave, using photogrammetric imaging technique. Tracks from the Malaval Cave are located inside the "Super-Blanches" galleries. More than 26 footprints were identified. They are Hettangian in age (Lower Jurassic) and preserved as both in situ convex hyporeliefs and ex situ concave epireliefs. Tree morphotypes are distinguished, (i) "Dilophosauripus- Kayentapus" morphotype, (ii) "Eubrontes" morphotype and (iii) "Grallatorid" morphotype. Sedimentological and mineralogical analyses of the tracksite indicate that the depositional environment varied from periodically emergent subtidal to intertidal/supratidal flat marsh. This work highlights the great interest and importance of palaeoichnological prospecting in karst caves. This is particularly true for the Causses Basin where hundreds of natural cavities were reported by speleologists in the formations yielding dinosaur traces. [ABSTRACT FROM AUTHOR]

Ichniotherium tracks with a relatively short pedal digit V (digit length ratio V/IV < 0.6) form themajority of yet described Late Carboniferous to Early Permian diadectomorph tracks and can be related to a certain diadectid clade with corresponding phalangeal reduction that includes Diadectes and its close relatives. Here we document the variation of digit proportions and trackway parameters in 25 trackways (69 step cycles) from nine localities and seven further specimens with incomplete step cycles from the type locality of Ichniotherium cottae (Gottlob quarry) in order to find out whether this type of Ichniotherium tracks represents a homogeneous group or an assemblage of distinct morphotypes and includes variability indicative for evolutionary change in trackmaker locomotion. According to our results, the largest sample of tracks from three Lower Permian sites of the Thuringian Forest, commonly referred to I. cottae, is not homogeneous but shows a clear distinction in pace length, pace angulation, apparent trunk length and toe proportions between tracks from Bromacker quarry and those from the stratigraphically older sites Birkheide and Gottlob quarry. Three Late Carboniferous trackways of Ichniotherium with relatively short pedal digit V from Haine's Farm, Ohio, and Alveley near Birmingham, United Kingdom, that have been referred to the ichnotaxa "Baropus hainesi," "Megabaropus hainesi" and "Ichniotherium willsi," respectively, share a marked outward rotation of foot imprints with respect to walking direction. Apart from this feature they are in many aspects similar to the Birkheide and Gottlob records of I. cottae. With the possible exception of the Maroon Formation (Early Permian, Colorado) sample, Early Permian Ichniotherium trackways with a relatively short pedal digit V fall into the morphological spectrum of the three well defined "Hainesi-Willsi," "Birkheide-Gottlob" and "Bromacker" morphotypes. With their more obtuse pace angulations and higher body-size-normalized pace and stride lengths the Bromacker type tracks imply higher walking speeds of their trackmakers compared to all other Ichniotheriumtracks. More generally, a trend towards higher locomotion capability from the last common ancestor of all Ichniotherium producers to the last common ancestor of all "Ichniotherium with relatively short pedal digit V" and from the latter to the trackmakers of the mid-Early Permian Bromacker type can be deduced--with the reservation that overall sample size is relatively small, making this scenario a preliminary assessment. Whether the presumed advancements represent a more general pattern within diadectomorphs remains open until the non-European Ichniotherium trackway record improves. Ichnotaxonomic implications are discussed. [ABSTRACT FROM AUTHOR]

Dinosaur trackways have rarely been reported in Cretaceous strata across the African continent. To the exception of ichnological occurrences in Morocco, Tunisia, Niger and Cameroon, our knowledge on the composition of Cretaceous dinosaur faunas mostly relies on skeletal evidence. For the first time, we document several dinosaur trackways from the Cretaceous of the Mamfe Basin in western Cameroon. Small and medium-size tridactyl footprints as well as numerous large circular footprints are present on a single horizon showing mudcracks and ripple marks. The age of the locality is considered Cenomanian-Turonian and if confirmed, this ichnological assemblage could be younger than the dinosaur footprints reported from northern Cameroon, and coeval with or younger than skeletal remains reported from the Saharan region. These trackways were left in an adjacent subsiding basin along the southern shore of the Benue Trough during a time of high-sea stand when the Trans-Saharan Seaway was already disconnecting West Africa from the rest of the continent. We predict that other similar track sites may be occurring along the margin of the Benue Trough and may eventually permit to test hypotheses related to provincialism among African dinosaur faunas. [ABSTRACT FROM AUTHOR]

The Anza site shows large ichnological surfaces indicating the coexistence in the same area of different vertebrate footprints (dinosaur and pterosaur) and of different types (tridactyl and tetradactyl, semiplantigrade and rounded without digit marks) and the footprint variability of long trackways. This area may become a world reference in ichnology because it contains the second undebatable African site with Cretaceous pterosaur footprints - described in part I - and the first African site with Macropodosaurus footprints. In this work, problems related to long trackways are also analyzed, such as their sinuosity, the order-disorder of the variability (long-short) of the pace length and the difficulty of morphological classification of the theropod footprints due to their morphological variability. [ABSTRACT FROM AUTHOR]

In Gondwana, Early Jurassic dinosaur track sites are especially concentrated in Lesotho. Despite intensive investigations during the third quarter of the twentieth century, a limited number of vertebrate track sites of this country have been studied with rigorous ichnological and sedimentological methodology. Here, we present a previously mentioned, but undescribed track site in the upper Elliot Formation (Hettangian?) of Lesotho, located near Roma (at Lephoto dam). Two tridactyl ichnite morphologies, made by bipedal vertebrate trackmakers are recognised. The first can be identified asGrallator-like, an ichnotaxon common in the Lower Jurassic of both Laurasia and Gondwana that can be attributed to small and medium-size theropod dinosaurs. In contrast, the second ichnite type is reminiscent ofTrisauropodiscus, which is a rare ichnotaxon that resembles tracks of small birds and is known with certainty in Lesotho from only a few places. We suggest that at our upper Elliot Formation study site,Trisauropodiscuswas potentially made by a heterodontosaurid ornithischian dinosaur. Our work provides further evidence that the ichnological record of the Stormberg Group of southern Africa is in a unique position to shed light not only on Early Jurassic biostratigraphy and palaeoenvironments but also on the biodiversity and palaeobiology of early dinosaurs. [ABSTRACT FROM AUTHOR]

Two relatively small tridactyl tracks from the Middle Jurassic Xintiangou Formation of northeastern Sichuan are assigned to cf. Anomoepus based on low length/width and anterior triangle ratios, and a relatively short step and inward rotation of the footprint axes. Anomoepus is typical of many Middle Jurassic dinosaur-dominated ichnofaunas from central and southern China and appears to be allied to the globally widespread Lower Jurassic tetrapod track biochron. [ABSTRACT FROM AUTHOR]