Dinosaur Tracks Research Articles

Hitchcock’s Leptodactyli, Penetrative Tracks, and Dinosaur Footprint Diversity

ABSTRACT Starting with his first report on fossil footprints from the Connecticut Valley over 180 years ago, Edward Hitchcock described what he interpreted as a burgeoning ancient fauna founded on ever-increasing nominal track diversity. For three decades, Hitchcock made countless contributions to ichnology, but his inference of thin-toed animals (Leptodactyli) from thin-toed tracks is flawed by modern criteria. Leptodactylous tracks are now recognized as variants made by thick-toed feet penetrating into soft, collapsing substrates. Herein, we take a closer look at the creation of such penetrative tracks using computer simulations of particle flow. Classic specimens are used to demonstrate how different modes of surface presentation make penetrative tracks challenging to recognize and interpret. Evaluation of 266 specimens from 43 leptodactylous ichnotaxa reveals that ∼90% are penetrative. We propose that a reliance on a single formation mechanism confounded Hitchcock’s ability to reliably recognize different trackmakers. This is not an old problem applicable only to fossils collected long ago; domination of a transmission-based model continues to bias the field today. Most texts and many publications either omit collapsed penetrative tracks or fail to recognize them as a significant source of variation. Without proper regard for subsurface toe movement and sediment flow, inferences of foot shape from track shape can, as for Hitchcock, be led far astray. The misidentification and misunderstanding of penetrative tracks impact our conception of the diversity of life in the Early Jurassic, as well as in other ichnofaunas worldwide.

Additional notes on the Mount Morgan dinosaur tracks from the Lower Jurassic (Sinemurian) Razorback beds, Queensland, Australia

ABSTRACT In a recent paper, community-held archival material was used to evaluate the palaeo-biology of dinosaur track-makers from the ‘fireclay caverns’ of Mount Morgan. With the ensuing interest, community members disclosed additional photographic documentation of Mount Morgan dinosaur tracks. The described theropodan and ornithischian tracks are consistent with the known Mount Morgan ichnofaunal record, while evidence of Anomoepus track-makers walking with the atypical plantigrade pedal posture has not been previously documented in Australia.

Developments and contributions in the study of La Rioja dinosaur footprints (Spain)

In this paper the study of dinosaur tracks of La Rioja, which began in 1970, is presented as an example of knowledge development, achievements, and events occurring around a paleontological resource having strong media impact. Fieldwork, research, and dissemination since the publication of the first scientific works have been accompanied by activities to protect sites and consider them as natural and cultural heritage. Finally it is shown how a paleontological resource has also led to the development of the tourist infrastructure in the area

Augmented Reality as a Tool for Promoting the Tourist Value of the Geological Heritage Around Natural Filming Locations: a Case Study in “Sad Hill” (The Good, the Bad and the Ugly Movie, Burgos, Spain)

Some natural scenes of films shooting contain landscapes and other elements that are part of the geological heritage, representing an added value for the growing cultural tourism that visits them. In the SE of Burgos province (Spain), near some filming locations of the classic western movie directed by Sergio Leone (1966), “The Good, the Bad and the Ugly”, we have assessed the Geological Heritage of 6 selected sites: (1) Dinosaur tracks; (2) Paleo-river structures preserved; (3) Fossil trees; (4) Sad Hill; (5) Marine Cretaceous fossils; and (6) La Yecla Gorge. Their tourist-cultural, scientific and educational values range from 775 points in La Yecla Gorge site to 450 in Marine Cretaceous fossils site. A virtual tour is presented implementing Augmented Reality on Google Earth with detailed but easily understanding descriptive information of each site, suggested activities for tourism and a free geoapp. The proposed technologies can enhance geotourism, favouring sustainable development and fostering attitudes and skills related to the tourist’s respect for nature.

Gigantic dinosaur footprints are found on the roof of a cave

Gigantic dinosaur footprints are found on the roof of a cave

The largest species of <italic>Asianopodus</italic> footprints from Junggar Basin, Xinjiang, China

A discovery has been made where thirteen footprints, two invertebrate traces and symmetrical ripple marks were found in a greyish green calcareous fine sandstone bed. The discovery was found in the Lower Cretaceous Shengjinkou Formation of Urho area, northwestern Junggar Basin, Xinjiang and it formed three trackways and four isolated tracks. Classic methods were used to study the dinosaur footprints in the Urho area, which included measuring the stratigraphic sections and the footprint parameters in the field. Similar standards of measurements were used for the measurement of footprint length and width, digit length and width, the divarication between digits, the length and width of anterior triangle, pace and stride lengths. In addition, photos of each footprint were taken and the orientation and distance between the neighboured tracks were measured. Distributions and outlines of the footprints were drawn in the computer by using CorelDRAW. On the other hand, silicone rubber demould was used for the well preserved specimens for a detailed research and from the detailed study of the footprints and trackways, two different types of theropod footprints were identified. The large three-toed footprints were a new species, named Asianopodus niui ichnosp. nov., which are large sized tridactyl (47.0–56.0 cm long and 31.0–42.0 cm wide, width/length between 0.66–0.75), the divarication between digits II and IV is 49.00°–55.34°, subsymmetrical, digit III is slightly longer than digit II, but more longer than digit IV, the length/width of anterior triangle between 0.34–0.37, V-shape tracks with a distinct bulbous heel impression, without manus and tail impressions, the phalangeal formula is 3-3-2, the pace length is between 164–180 cm, the stride length is 328–336 cm. It is significant to note that this is the largest Asianopodus footprints that have been discovered. The medium-sized tracks belong to Asianopodus pulvinicalx , which are middle sized tridactyl (21.0–27.0 cm long and 18.0–20.0 cm wide, width/length between 0.72–0.86), the divarication between digits II and IV is 46.63°–51.40°, subsymmetrical, digit III is more longer than digit II and digit IV, the length/width of anterior triangle between 0.44–0.54, V-shape tracks with a distinct bulbous heel impression and without manus and tail impressions, the phalangeal formula is 3-3-3, the pace length is between 76.5–83.2 cm, the stride length is 160 cm. According to the footprint length, pace and stride length, relative stride length of the tracks, we calculated that the body length of A. niui ichnosp. nov. is 5.89 m and the speed is 8.14 km/h, while the body length of A. pulvinicalx is 2.52 m and speed is 6.48 km/h. Based on the symmetric ripple marks and invertebrate traces on the surface of the footprints layer, we infered that both the trackmakers of the Urho dinosaur footprints walked in the shore and shallow lacustrine environment.

Novel track morphotypes from new tracksites indicate increased Middle Jurassic dinosaur diversity on the Isle of Skye, Scotland.

Dinosaur fossils from the Middle Jurassic are rare globally, but the Isle of Skye (Scotland, UK) preserves a varied dinosaur record of abundant trace fossils and rare body fossils from this time. Here we describe two new tracksites from Rubha nam Brathairean (Brothers’ Point) near where the first dinosaur footprint in Scotland was found in the 1980s. These sites were formed in subaerially exposed mudstones of the Lealt Shale Formation of the Great Estuarine Group and record a dynamic, subtropical, coastal margin. These tracksites preserve a wide variety of dinosaur track types, including a novel morphotype for Skye: Deltapodus which has a probable stegosaur trackmaker. Additionally, a wide variety of tridactyl tracks shows evidence of multiple theropods of different sizes and possibly hints at the presence of large-bodied ornithopods. Overall, the new tracksites show the dinosaur fauna of Skye is more diverse than previously recognized and give insight into the early evolution of major dinosaur groups whose Middle Jurassic body fossil records are currently sparse.

Archival data provides insights into the ambiguous track-maker gait from the Lower Jurassic (Sinemurian) Razorback beds, Queensland, Australia: evidence of theropod quadrupedalism?

ABSTRACT 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.

Ruta de La Reserva de la Biosfera de La Rioja: ejemplo de integración entre ser humano y medio

Biosfera (MaB) de la UNESCO. Es un ejemplo de lo que representan estos espacios desde el punto de vista social, económico y científico para la conservación del medio dentro del marco del desarrollo sostenible. Incluye a 40 municipios marcados por el declive demográfico, la falta de servicios y de accesibilidad, pero también afortunados por el patrimonio natural y cultural que atesoran. El aprovechamiento como recurso de las formaciones geológicas y el relieve, la biodiversidad, las icnitas, las aguas termales, la fisonomía de los pueblos y las manifestaciones culturales en la Reserva convive con la actividad humana en un equilibrio armonioso que exige un esfuerzo continuado. La lucha por su supervivencia es el reto más importante al que se enfrentan sus habitantes, como actores del territorio, y el conjunto de la sociedad como responsables de su conservación para el disfrute de las generaciones futuras.

On the devil's tracks: unexpected news from the Foresta ichnosite (Roccamonfina volcano, central Italy)

ABSTRACTThe Foresta ichnosite is well known for preserving some of the oldest human fossil footprints recorded in Europe so far. This research aims to: i) describe new footprints that are larger than those already reported, some of which form a new trackway that moves in the opposite direction to all the others; ii) announce the discovery of some stone tools also in the surroundings of the Foresta ichnosite. The new results increase the total number of human fossil footprints to at least 81, specify the direction and the number of footprints of Trackway C, and identify three new directions of walking at the site. More compelling and complete estimates of the dimensional range of all ichnological evidence enables us, furthermore, to estimate the number of trackmakers walking on the trampled surface as a minimum of five, one of them likely being an adult male. The general shape of all the recorded footprints suggests that the Foresta trackmakers share some similarities with those at Sima de los Huesos, and belong to the same taxonomical group as the Ceprano skull. All the new evidence enables us to better understand the presence of hominin populations in the Roccamonfina volcano area during the Middle Pleistocene. © 2020 John Wiley & Sons, Ltd.

First Upper Cretaceous dinosaur track assemblage from Jordan (Middle East) – preliminary results

Dinosaur tracks from Jordan (Middle East) have only been briefly reported in geological overview papers and books. We present here the first description and documentation of Jordanian dinosaur tracks based on a new tracksite from the south-central part of the country. The track-bearing strata belong to marginal marine (tidal flat) deposits of the Na’ur Formation (Upper Cretaceous, Cenomanian). This unit largely consists of well-bedded limestones, dolomites and marls that contain abundant marine invertebrate fossils such as bivalves, ammonites and foraminifers. The dinosaur ichnofauna occurs on four different levels and comprises abundant theropod tracks and trackways as well as isolated sauropod and ornithopod tracks. Theropod trackways consist of two different morphotypes. Morphotype 1 is tridactyl (26 cm pes length) and with a broad, but short metatarsal area and resembles the ichnogenus Picunichnus from the Lower Cretaceous (Albian) of Argentina. Morphotype 2 (36 cm pes length) has extensive and narrow metatarsal impressions continuously occurring along regularly-spaced trackways. This suggests either a plantigrade movement of the trackmaker or reflects preservational factors. By their overall-shape with thin digits, Morphotype 2 resembles described penetrative tracks suggesting a strong influence of the substrate. Sauropod tracks are relatively small (40 cm pes length) and show low heteropody with a kidney-shaped manus imprint, pointing to a Sauropodichnus -like form. The single ornithopod pes track (18 cm in length) is similar to material described as Ornithopodichnus from the Lower Cretaceous of Korea. Due to the incomplete material of sauropod and ornithopod prints, no concrete assignment is given to this material and further study is needed. The presence of dinosaur tracks proves a temporary subaerial exposure of the surface whereas the main part of the Na’ur Formation is dominated by subaqueous activity of marine faunas.

新疆阿尔金山内首次发现恐龙足迹化石

新疆阿尔金山内首次发现恐龙足迹化石

Large tridactyl dinosaur tracks from the Early Jurassic of southern Gondwana – uppermost Elliot Formation, Upper Moyeni, Lesotho

A new ichnosite in southwest Lesotho (Upper Moyeni; Quthing District) is located within the uppermost part of the highly fossiliferous Elliot Formation, ~35 m below the conformably overlying Clarens Formation and ~65 m above the world-renowned Lower Moyeni ichnosite. While the Lower Moyeni site preserves diverse Early Jurassic ichnofossils, the ichnites at the Upper Moyeni comprise one vertebrate burrow and ~50 tridactyl tracks with footprint lengths between 15 and 51 cm. Many of the tracks preserve digital pad impressions, claw marks and displacement rims, all related to substrate conditions. The morphometric parameters of the Upper Moyeni tracks are consistent with Grallator , Eubrontes and Kayentapus . Several larger tracks with footprint lengths > 40 cm are Kayentapus -like and Eubrontes -like, and are comparable to previously described very large theropods tracks with lengths > 50 cm from the uppermost Elliot and Clarens formations. On the basis of sedimentological and ichnological evidence, the Upper Moyeni ichnofossils were formed in a palaeolandscape with small rivers and shallow lakes by burrowing tetrapods and a variety of bipedal dinosaurs (theropods), some of which were up to 7–8 m in body length. The Upper Moyeni tracks, together with the other very large tracks from coeval locations in southern Africa, collectively highlight the tendency towards increasing diversity in size of tridactyl tracks and by extension theropod trackmaker body size body size, which runs in tandem with the increasing diversity of non-sauropod, sauropodomorph body fossils in the Sinemurian-Pliensbachian of southern Gondwana.

Index to Titles and Authors/Editors of Books Reviewed

Index to Titles and Authors/Editors of Books Reviewed

Geoconservation of the paleontological heritage of the geosite of dinosaur footprints (sauropods) in the locality of São Domingos, municipality of Itaguatins, state of Tocantins, Brazil

The present study aimed at performing a quantitative evaluation to propose a geoconservation plan to the Sao Domingos geosite, and, therefore, to contribute with feasible actions, to the preservation of this paleontological heritage. The study area is located in the district in the Itaguatins municipality, northern Tocantins state, Brazil. The studied geosite is characterized by the presence of track fossils. The tracks have been assigned to herbivorous dinosaurs, basal sauropods, which were living in the area during the first periods of the Cretaceous. The following aspects were quantitatively evaluated: risk of degradation and potential for the educational and touristic use of the area. All these aspects were quantitatively evaluated with the methodology described in the app web GEOSSIT, administered by the Companhia de Pesquisa de Recursos Minerais. The Sao Domingos geosite has a high scientific value, with a national relevance, a moderate potential of educational use, a low potential of tourist use, and a high risk of degradation. The site, with interest and paleontological value, has the potential to be used in all level educational activities at, and it is important it should be used for such activities. The elements of the geosite are currently in an advanced degree of degradation, and urgent measures are required to mitigate the erosive activities that affect the footprint-bearing surfaces and that gradually increase their erosion.

Stitch in the ditch: Nutzotin Mountains (Alaska) fluvial strata and a dike record ca. 117–114 Ma accretion of Wrangellia with western North America and initiation of the Totschunda fault

AbstractThe Nutzotin basin of eastern Alaska consists of Upper Jurassic through Lower Cretaceous siliciclastic sedimentary and volcanic rocks that depositionally overlie the inboard margin of Wrangellia, an accreted oceanic plateau. We present igneous geochronologic data from volcanic rocks and detrital geochronologic and paleontological data from nonmarine sedimentary strata that provide constraints on the timing of deposition and sediment provenance. We also report geochronologic data from a dike injected into the Totschunda fault zone, which provides constraints on the timing of intra–suture zone basinal deformation. The Beaver Lake formation is an important sedimentary succession in the northwestern Cordillera because it provides an exceptionally rare stratigraphic record of the transition from marine to nonmarine depositional conditions along the inboard margin of the Insular terranes during mid-Cretaceous time. Conglomerate, volcanic-lithic sandstone, and carbonaceous mudstone/shale accumulated in fluvial channel-bar complexes and vegetated overbank areas, as evidenced by lithofacies data, the terrestrial nature of recovered kerogen and palynomorph assemblages, and terrestrial macrofossil remains of ferns and conifers. Sediment was eroded mainly from proximal sources of upper Jurassic to lower Cretaceous igneous rocks, given the dominance of detrital zircon and amphibole grains of that age, plus conglomerate with chiefly volcanic and plutonic clasts. Deposition was occurring by ca. 117 Ma and ceased by ca. 98 Ma, judging from palynomorphs, the youngest detrital ages, and ages of crosscutting intrusions and underlying lavas of the Chisana Formation. Following deposition, the basin fill was deformed, partly eroded, and displaced laterally by dextral displacement along the Totschunda fault, which bisects the Nutzotin basin. The Totschunda fault initiated by ca. 114 Ma, as constrained by the injection of an alkali feldspar syenite dike into the Totschunda fault zone.These results support previous interpretations that upper Jurassic to lower Cretaceous strata in the Nutzotin basin accumulated along the inboard margin of Wrangellia in a marine basin that was deformed during mid-Cretaceous time. The shift to terrestrial sedimentation overlapped with crustal-scale intrabasinal deformation of Wrangellia, based on previous studies along the Lost Creek fault and our new data from the Totschunda fault. Together, the geologic evidence for shortening and terrestrial deposition is interpreted to reflect accretion/suturing of the Insular terranes against inboard terranes. Our results also constrain the age of previously reported dinosaur footprints to ca. 117 Ma to ca. 98 Ma, which represent the only dinosaur fossils reported from eastern Alaska.

Microbial structures and dinosaur trackways from a Cretaceous coastal environment (Dakota Group, Colorado, U.S.A.)

ABSTRACT Microbially induced sedimentary structures may help preserve unique glimpses of ancient shoreline habitats, but are little known from Mesozoic epicontinental settings. To help fill this knowledge gap, we describe a diverse suite of microbial structures from the Upper Cretaceous “J” Sandstone (South Platte Formation, Dakota Group) that are spectacularly exposed at Dinosaur Ridge in Morrison, Colorado, USA. Structures include “tattered” bed surfaces and ferruginous sand chips in supratidal flat facies. A large over-flip structure is preserved in a channel locally known as Crocodile Creek. In upper-intertidal facies, multidirectional ripple marks occur. Perhaps the most well-known microbial structures are exposed on extensive bedding surfaces known as “Slimy Beach,” where lower supratidal-flat facies are dominated by decimeter-scale erosional remnants and pockets. Morphologies and superposition of the structures allows identification of three generations of erosional pockets. Generation A of these erosional pockets exhibit size similarities to ornithomimid, sauropod, and ornithopod dinosaur tracks from adjacent bedding planes, raising the question of whether initial disturbance of the mat-bound surface could have been from track making. Generation B erosional pockets are older and record continuous erosion of the initial pockets until they were eventually overgrown and sealed by microbial mats. Generation C pockets are the oldest ones, exposing wide areas of barren sediment that could not be overgrown by microbial mats anymore. In concert, the microbial structures point to seasonally variable meteorological conditions along the coastline of the Western Interior Seaway and indicate that the “Slimy Beach” bedding plane represents a multi-year record of dinosaur locomotion.

Dinosaur tracks from the Jurassic-Cretaceous boundary Tuchengzi Formation (Hebei Province, China) used as building stones in the Chengde imperial summer resort: Age, ichnology, and history

Slabs with tetrapod tracks from the Madigou Village quarry in the Tuchengzi Formation have famously been used as building stones at the imperial summer resort locality, also referred to in the ichnological literature as the “Chengde Summer Palace.” The Jurassic-Cretaceous boundary Tuchengzi Formation has elsewhere in the region yielded differently composed ichnofaunas with non-avian and avian theropod and sauropod tracks. The Madigou assemblage is remarkable because it shows the co-occurrence of abundant and diverse non-avian and avian theropod tracks. The non-avian theropod tracks are mostly Grallator- and Eubrontes-like with a few that registered faint hallux traces. A small number of didactyl deinonychosaurian tracks were recognized which we here label as Velociraptorichnus isp. The avian theropod tracks can tentatively be referred to Aquatilavipes and Koreanaornis, with wide digit divarications. Growing geochronological and biostratigraphic evidence suggests that these are among the oldest known bird tracks, similar in age to Pullornipes, also from the Tuchengzi Formation in northeastern China and dating close to the Tithonian-Berriasian boundary. Theropod tracks are dominating, even if an isolated possible sauropod track and some questionable tridactyl imprints that could either represent theropods or ornithopods, may indicate the presence of further dinosaur groups. The Tuchengzi ichnofauna is important because of the stratigraphic age close to the famous Jehol Biota.

Public Understanding on Geoconservation Strategies at the Passagem das Pedras Geosite, Paraíba (Brazil): Contribution to the Rio do Peixe Geopark Proposal

The Rio do Peixe basin, which is developed during the Lower Cretaceous, consists of the Sousa, Uirauna-Brejo das Freiras, Pombal and Vertentes sub-basins. They have abundant ichnofauna represented by dinosaur tracks of theropods, sauropods and ornithopods, these being the main objects of geological heritage in the region. The majority of palaeontological sites are found in the Sousa basin and the most important geosite in terms of distribution of fossil footprints is Passagem das Pedras (Municipality of Sousa—Sousa basin). In 1992, this area was classified as the “Valley of the Dinosaurs Natural Monument” and initially had high-quality infrastructure and trained tour guides; however, following a period of neglect, the local infrastructure became precarious. In 2014, revitalization of the museum, kiosks and walkways in Valley was performed; however, there are inefficient measures to protect the dinosaur footprints from human and natural threats. Thus, 500 interviews with the urban and rural population of Sousa in addition to traders and teachers were done, seeking public understanding of geoconservation strategies at the Passagem das Pedras geosite. Critical analysis of the results was performed as a contribution to the proposal for the Rio do Peixe Geopark. The perception is that the geoconservation strategies are not effective in protecting the Passagem das Pedras geosite or in raising the Sousa population’s awareness as to the importance of geological heritage. The other palaeontological sites of the Sousa basin are also quite vulnerable and with deteriorating geological elements. Therefore, the region currently has low potential to become a geopark.

Middle Jurassic Tracks of Sauropod Dinosaurs in a Deep Karst Cave in France

ABSTRACT Although the deep galleries of natural underground cavities are difficult to access and are sometimes dangerous, they have the potential to preserve trace fossils. Here, we report on the first occurrence of sauropod dinosaur tracks inside a karstic cave. Three trackways are preserved on the roof of the Castelbouc cave 500 m under the surface of the Causse Méjean plateau, southern France. The tracks are Bathonian in age (ca. 168–166 Ma), a crucial but still poorly known time interval in sauropod evolution. The three trackways yield sauropod tracks that are up to 1.25 m long and are therefore amongst the largest known dinosaur footprints worldwide. The trackmakers are hypothesized to be titanosauriforms. Some of the tracks are extremely well preserved and show impressions of digits, digital pads, and claws. We erect the new ichnogenus and ichnospecies Occitanopodus gandi, igen. et isp. nov. In order to characterize depositional environments, we conducted sedimentological, petrographic, and mineralogical analyses. The tracks from Castelbouc attest the presence of sauropods in proximal littoral environments during the Middle Jurassic. This discovery demonstrates the great potential of prospecting in deep karst caves that can occasionally offer larger and better-preserved surfaces than outdoor outcrops.