Dinosaur Tracks Research Articles

The first record of dinosaur tracks from the Cretaceous Zhagang Group of the northwestern Guangdong Province, China

ABSTRACT The Jurassic and Cretaceous tetrapod track record in China has incrementally expanded due to the discovery of small sites in widely dispersed geographical locations, which often lack body fossils. Many of these are theropod dominated tracksites where, despite morphological variation, identification of ichnotaxa is difficult at low taxonomic levels (i.e., ichnogenus/ichnospecies assignments). Here we report on an Early to mid-Cretaceous site from the Mawu Formation (Zhagang Group) in Guangdong Province, China, a region thus far scarcely known from dinosaur fossils. The new site yielded three different morphotypes tentatively labelled as a Paracorpulentapus-eubrontid-grallatorid assemblage. It is noted that similar assemblages have been identified from Cretaceous deposits in Sichuan and Anhui provinces of China.

Dinosaur footprints from the Early Jurassic of Le Mazel (Lozère, Southern France)

During the 20th century, the first dinosaur tracks of the Causses Basin were identified at Saint-Laurent-de-Trèves, in the Parc National des Cévennes (southern France). A recent excavation reveals a new theropod tracksite in the Hettangian deposits from Le Mazel, 2km from the historical tracksite at Saint-Laurent-de-Trèves. The tracks are here described combining a biometric approach and 3D imaging photogrammetry. The main track-bearing surface bears 64 in situ tridactyl footprints preserved as concave epireliefs. Two morphotypes were identified, a “Grallatorid” morphotype and a “Kayentapus” morphotype. Footprints belonging to the first morphotype are closely similar to Grallator lescurei, Grallator minusculus, and Grallator sauclierensis. This study shows the difficulty to distinguish quite similar tridactyl tracks from an ichnotaxonomic point of view and highlights the importance of detailed biometric comparisons. Tracks are preserved in a brown to yellowish dolomudstone showing abundant cryptalgal laminites and mud cracks. These deposits were accrued in shallow environments such as intertidal and supratidal zones of a tidal flat.

Human (boot) tracks preserved in volcanic deposits of Surtsey Island, Iceland

Several human boot tracks and trackways are preserved in palagonitized tuff in Surtsey Island, south Iceland. The underlying palagonitized substrate is made of reworked tephra debris talus and slump material that lies partly on top of lava flows erupted in 1964–1965 in Surtungur tuff crater and 1966–1967 in Surtur tuff crater. This stratigraphic information along with other evidence from the nature of the sediments, alteration history of the deposits and the record of human presence on the island indicate the tracks were formed in the years between 1967 and 1970. The exquisite preservation and consolidation of the tracks coincide with a period of rapid geomorphic changes in the early stages of development of the island, when the newly formed tephra was still unconsolidated and easily mobilized by mass movements, wind and runoff. Furthermore, cooling magmatic intrusions generated hydrothermal activity on the island speeding up diagenesis of the tephra and the cementation of the boot tracks in the substrate. Expulsion rims preserved in some of the boot tracks suggests the tracks were formed in moderately cohesive substrate, followed by rapid burial of the prints in heavy wind and/or storm. Three boot sizes were identified suggesting the tracks were made by at least three persons, and documentation of the boot anatomy, measurements on angle of gait, stride and pace reveal the direction of movement for each trackway. Intense erosion of the tuff cones has exhumed the tracks to the surface that stand today as a testimony to impressively rapid geological cycles for preservation and exhumation and the role of unstable and rapidly changing environments, the aftermath of high-energy events, in capturing and preserving ichnites. These boot tracks are the first fossil tracks described for Iceland and the first record in the world of boot tracks preserved in sedimentary rocks.

Human (boot) tracks preserved in volcanic deposits of Surtsey Island, Iceland

Several human boot tracks and trackways are preserved in palagonitized tuff in Surtsey Island, south Iceland. The underlying palagonitized substrate is made of reworked tephra debris talus and slump material that lies partly on top of lava flows erupted in 1964–1965 in Surtungur tuff crater and 1966–1967 in Surtur tuff crater. This stratigraphic information along with other evidence from the nature of the sediments, alteration history of the deposits and the record of human presence on the island indicate the tracks were formed in the years between 1967 and 1970. The exquisite preservation and consolidation of the tracks coincide with a period of rapid geomorphic changes in the early stages of development of the island, when the newly formed tephra was still unconsolidated and easily mobilized by mass movements, wind and runoff. Furthermore, cooling magmatic intrusions generated hydrothermal activity on the island speeding up diagenesis of the tephra and the cementation of the boot tracks in the substrate. Expulsion rims preserved in some of the boot tracks suggests the tracks were formed in moderately cohesive substrate, followed by rapid burial of the prints in heavy wind and/or storm. Three boot sizes were identified suggesting the tracks were made by at least three persons, and documentation of the boot anatomy, measurements on angle of gait, stride and pace reveal the direction of movement for each trackway. Intense erosion of the tuff cones has exhumed the tracks to the surface that stand today as a testimony to impressively rapid geological cycles for preservation and exhumation and the role of unstable and rapidly changing environments, the aftermath of high-energy events, in capturing and preserving ichnites. These boot tracks are the first fossil tracks described for Iceland and the first record in the world of boot tracks preserved in sedimentary rocks.

A high-density Grallator assemblage from the Haman Formation (Cretaceous), Korea: implications for Cretaceous distribution of grallatorids in east Asia

ABSTRACT Monospecific assemblages of non-avian theropod tracks are relatively rare in the Cretaceous of Korea, where assemblages dominated by the tracks of diverse tetrapods (birds, sauropods, ornithopods, and pterosaurs) are well known and widely distributed in the Haman and Jindong formations (Hayang Group). To date, few high-density assemblages of theropod tracks have been documented. A Haman Formation site on Adu Island reveals a small high-density assemblage of Grallator tracks (~29 tracks/m2). The tracks, which indicate registration on a sandy substrate infused with microbial mat, are indistinguishable from Grallator tracks known from a few other Lower Cretaceous sites in China and east Asia. Early and Middle Jurassic Grallator-dominated assemblages are common in east Asia, and persist into the Late Jurassic- Early Cretaceous (Neocomian) transition in China, where they are typically only associated with sauropodomorph tracks. Post-Neocomian (Aptian-Albian) Cretaceous assemblages from Korea are much more diverse, and characterised by tracks of sauropod and ornithopod dinosaurs, non-avian and avian theropods (birds), pterosaurs and other tetrapods. Post-Neocomian assemblages dominated by theropod tracks, are rare and no large monospecific grallatorid assemblages are currently known.

Stegosaur tracks from the Upper Jurassic of Portugal: new occurrences and perspectives

The record of Late Jurassic stegosaur tracks from the Lourinhã Formation (Kimmeridgian-Tithonian) is here revised. Thirty-eight dinosaur tracks, preserved as natural infill casts, are here reported, and thirty-two of them are attributed to the ichnogenus Deltapodus. Four of those present impressions of skin, with polygonal scales and random pattern. Deltapodus is the most common ichnogenus in the track record of the Lourinhã Formation. The sizes and shape suggest one single dacentrurine trackmaker, which could be Miragaia longicollum, also common in the same horizons.

Two new dinosaur tracksites from the Jurassic Guizhou Province, China

ABSTRACT Two newly discovered dinosaur track locations near the town of Bijie in Guizhou Province, southwestern China are named the Yuanbaoqing and Yejiatian tracksites. They represent the Lower Jurassic Maanshan Member of the Zijiujing Formation and Upper Jurassic Xiashaximiao Formation, respectively. The former Yuanbaoqing tracksite reveals a minimum of three Anomoepus trackways and two poorly preserved incomplete sauropod trackways, tentatively assigned here to cf. Brontopodus. They occur in shallow lake to shoreline facies depositional environments. The Yejiatian site shows a well-preserved, narrow-gauge sauropod trackway in a delta plain facies which is identified as Parabrontopodus. The occurrences enhance the local faunal record in Guizhou Province were previous tracksite reports for these stratigraphic intervals are sparse. In the broader regional context of southwestern China the track record is consistent with the body fossil record in both the Lower and Upper Jurassic of this region.

Late Triassic dinosaur tracks from Penarth, south Wales

AbstractEvidence of Late Triassic large tetrapods from the UK is rare. Here, we describe a track-bearing surface located on the shoreline near Penarth, south Wales, United Kingdom. The total exposed surface is c. 50 m long and c. 2 m wide, and is split into northern and southern sections by a small fault. We interpret these impressions as tracks, rather than abiogenic sedimentary structures, because of the possession of marked displacement rims and their relationship to each other with regularly spaced impressions forming putative trackways. The impressions are large (up to c. 50 cm in length), but poorly preserved, and retain little information about track-maker anatomy. We discuss alternative, plausible, abiotic mechanisms that might have been responsible for the formation of these features, but reject them in favour of these impressions being tetrapod tracks. We propose that the site is an additional occurrence of the ichnotaxon Eosauropus, representing a sauropodomorph trackmaker, thereby adding a useful new datum to their sparse Late Triassic record in the UK. We also used historical photogrammetry to digitally map the extent of site erosion during 2009–2020. More than 1 m of the surface exposure has been lost over this 11-year period, and the few tracks present in both models show significant smoothing, breakage and loss of detail. These tracks are an important datapoint for Late Triassic palaeontology in the UK, even if they cannot be confidently assigned to a specific trackmaker. The documented loss of the bedding surface highlights the transient and vulnerable nature of our fossil resources, particularly in coastal settings, and the need to gather data as quickly and effectively as possible.

Robert McNeill Alexander. 7 July 1934—21 March 2016

Neill Alexander graduated in natural sciences at the University of Cambridge in 1955. After a PhD at Cambridge and a lecturership at the University College of North Wales in Bangor, he was appointed to the chair of the Department of Pure and Applied Zoology at the University of Leeds in 1969. At that stage, he switched his research interests abruptly from fishes to the mechanics of legged locomotion. He conducted experiments with a variety of mammals, calculating forces, stresses and strains in muscle fibres, bones and tendons. His speciality became the application of mathematical models to animal locomotion, including repurposing the Froude number, devised by the Victorian engineer William Froude (FRS 1870) for use with ships, to estimate the speed of dinosaurs based on the spacing of their fossil footprints. Subsequent work included modelling the optimization of mammal performance and the minimization of energy costs. In 1992, following an announcement that London Zoo would have to close as a result of shortage of funds, Neill was appointed secretary of the Zoological Society of London. During the period of his secretaryship, the Society's finances recovered, with both its zoos (London and Whipsnade) breaking even in 1993 and the Society returning a surplus in each subsequent year. Neill was awarded the CBE in 2000. The National Portrait Gallery holds his portrait by John Arnison.

Ichnology and sedimentology of the Coniacian non-marine Frontier Formation, western Centennial Mountains, southwestern Montana, USA

ABSTRACT 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.

First occurrence of sauropod and theropod footprints in the pre‐Campanian deposits of the Nubian Sandstone, south Eastern Desert, Egypt

Dinosaur footprints occur in the Upper Cretaceous strata known as the Nubian Sandstone Formation in the south Eastern Desert, Egypt. The Nubian Sandstone unit is subdivided into three informal members: A lower member is marked by reddish‐brown, trough cross‐bedded, coarse‐ to medium‐grained sandstone interbedded with thin beds of varicolored mudstone, reflecting deposition in a braided fluvial system, a middle member is characterized by reddish‐white to yellow, planar cross‐bedded, medium‐grained sandstone with ferruginous siltstone intercalations, interpreted as meandering fluvial deposits, and an upper member consists of repeated coarsening‐upward cycles of rippled siltstone to fine‐ to medium‐grained sandstone and planar cross‐bedded, yellowish‐white sandstone, containing many vertebrate footprints and invertebrate trace fossils, reflecting deposition in a coastal to deltaic environment. Sixteen dinosaur footprints are recorded at the base of the upper member of the Nubian Sandstone, on inclined surfaces of rippled, fine‐grained sandstones. Twelve are overlapping each other and belong to distinct individuals of dinosaurs, the other four are distributed on a younger bedding surface. Twelve footprints are from more than one sauropod dinosaur, while three of the isolated footprints belong to a theropod dinosaur. The footprints described are semiplantigrade and digitigrade. This discovery is the second record of tetrapod footprints in Egypt and the first record of tetrapod footprints in the Eastern Desert.

A new dinosaur tracksite from the Lower Cretaceous (Aptian–Albian) Eumeralla Formation of Wattle Hill, Victoria, Australia: a preliminary investigation

ABSTRACT Dinosaur fossils of the Lower Cretaceous (Aptian–Albian) Eumeralla Formation (Otway Basin) of Victoria provide insights into the faunal and ichnofaunal diversity of southern hemisphere high latitude dinosaurs during the initial separation of Australia from Antarctica. To date, at least eight dinosaur fossil locations have been reported from this formation. In this paper, we describe a new tracksite locality along the coastline of Wattle Hill that represents the most westerly occurrence of dinosaur fossils in the state. Some of the Wattle Hill prints resemble tracks attributed to ornithopodan trackmakers from neighbouring tracksites of the Eumeralla Formation (Knowledge Creek, Browns Creek), while others resemble bird prints. The site also preserves a large non-avian theropod footprint that resembles Megalosauropus prints from the Lower Cretaceous (Valanginian–Barremian) Broome Sandstone, Western Australia that if correct, extends the temporospatial range of this ichnogenus. The Wattle Hill tracks vary in their erosion between and within tracksites, from a natural mould (concave epirelief), transmitted tracks, possibly penetrative tracks and infilled reliefs that resemble (but differ from) natural casts. With the constant weathering of the Eumeralla Formation exposures, it seems likely that additional dinosaur tracks fossils will be discovered with continued Victorian coastal explorations.

A new solution to an old riddle: elongate dinosaur tracks explained as deep penetration of the foot, not plantigrade locomotion

AbstractThe dinosaur track record features numerous examples of trackways with elongated metatarsal marks. Such ‘elongate tracks’ are often highly variable and characterized by indistinct outlines and abbreviated or missing digit impressions. Elongate dinosaur tracks are well‐known from the Paluxy River bed of Texas, where some have been interpreted as ‘man tracks’ by creationists due to their superficially human‐like appearance. The horizontal orientation of the metatarsal marks led to the now widely accepted idea of a facultative plantigrade, or ‘flat‐footed’, mode of locomotion in a variety of dinosaurian trackmakers small to large. This hypothesis, however, is at odds with the observation that elongate tracks do not indicate reduced locomotion speeds and increased pace angulation values, but instead are correlated with low anatomical fidelity. We here interpret elongate tracks as deep penetrations of the foot in soft sediment. Sediment may collapse above parts of the descending foot, leaving a shallow surface track that preserves a metatarsal mark. The length of a metatarsal mark is determined by multiple factors and is not necessarily correlated with the length of the metatarsus. Other types of posterior marks in dinosaur footprints, such as drag and slip marks, are reviewed.

One size fits all? Stature estimation from footprints and the effect of substrate and speed on footprint creation.

Estimation of stature from footprint lengths is a common prediction in forensic cases and in paleoanthropology upon the discovery of fossil footprints. Many studies, which have estimated stature from footprints, generally use a "one-size-fits-all" approach that usually involves applying a known ratio of foot length to total stature to do so, although this method has fallen out of practice in forensic cases in recent years but is still commonly used for fossil trace evidence. Yet, we know that substrate and speed can change the dimensions of a footprint, so why are these "one-size-fits-all" approaches still used today? We tested footprint production across different substrates at a walk, a fast walk, and a jog. We calculated how accurately footprint dimensions were impressed between these different conditions and identified sources of error in footprint lengths, and the percentage changes of how significantly a footprint can change in length between different conditions. We provide a table with different ratios that we encourage practitioners/field scientists to refer to and use when estimating stature from footprints, with respect to the substrate on which the footprint was created and the speed at which it was created. We actively encourage researchers to add the ratios by testing more substrates so that in the future stature can be more accurately estimated, thus aiding the paleoanthropological community, but also forensic investigations by statistically highlighting how different conditions can affect trace dimensions.

Fast-running theropods tracks from the Early Cretaceous of La Rioja, Spain

Theropod behaviour and biodynamics are intriguing questions that paleontology has been trying to resolve for a long time. The lack of extant groups with similar bipedalism has made it hard to answer some of the questions on the matter, yet theoretical biomechanical models have shed some light on the question of how fast theropods could run and what kind of movement they showed. The study of dinosaur tracks can help answer some of these questions due to the very nature of tracks as a product of the interaction of these animals with the environment. Two trackways belonging to fast-running theropods from the Lower Cretaceous Enciso Group of Igea (La Rioja) are presented here and compared with other fast-running theropod trackways published to date. The Lower Cretaceous Iberian fossil record and some features present in these footprints and trackways suggest a basal tetanuran, probably a carcharodontosaurid or spinosaurid, as a plausible trackmaker. Speed analysis shows that these trackways, with speed ranges of 6.5–10.3 and 8.8–12.4 ms−1, testify to some of the top speeds ever calculated for theropod tracks, shedding light on the question of dinosaur biodynamics and how these animals moved.

Fish swim traces from the Jindong Formation (Cretaceous) Korea: Implications for lake basin ichnofacies and paleoecology

The track rich Cretaceous Jindong Formation is famous for abundant tetrapod track assemblages, which occur at multiple, closely-spaced stratigraphic levels in the Gyeongsang Basin lake deposits of South Korea. However, until now no fish traces or fish body fossils had been reported. Thus, the discovery of three Undichna ichnospecies (U. simplicitas, U. bina, and U. britannica) provide the first direct evidence of fish in the basin. Paired in-phase traces vary in width and indicate a range of fish sizes among the tracemakers. Undichna assemblages represent a shallow lacustrine Undichna ichnocoenosis. Bird tracks (Ignotornis) registered on the same surface represent the superposition of a shorebird ichnocoenosis. Dinosaur tracks (Brontopodus and Caririchnium) associated with surfaces only ∼1 m below the bird and fish traces, represent additional large tetrapod ichnocoenoses, and demonstrate multiple, superimposed ichnocoenoses, interpenetrating localized sedimentary successions which are little separated in space or time. The Undichna and shorebird, ichnocoenoses are considered, in schema followed here, as representative of higher-level ‘archetypal’ Charachichnos and Grallator ichnofacies respectively. However, it is not clear whether a third ichnocoenosis and ichnofacies is represented by the Brontopodus and Caririchnium assemblages or the extent to which the overprinting of different ichnofaunas in localized areas always allows for the unambiguous application of ichnocoenois and ichnofacies schema.

Sedimentology and ichnology of the mid-Cretaceous succession of Ouled Nail Mounts (Eastern Saharan Atlas, Algeria)

Shallow marine deposits characterize the upper Albian – lower Cenomanian deposits of Northern Algeria. In Djebel Azzeddine (Ouled Nail Mounts), the corresponding sediments have been subdivided into three distinctive units A to C. The first discovered ammonite fauna from the Bou Saada area allowed the attribution of a part of the mid-Cretaceous post-Continental Intercalaire deposits to the upper Albian. The ammonite-bearing level indicates a maximum flooding surface and could be correlated with similar levels from Northern Algeria. The studied succession is characterized by a low ichnodiversity containing eight ichnotaxa with abundant Thalassinoides, common Skolithos, and rare Gyrolithes, Oichnus, Planolites and cf. Tisoa. This ichnoassemblage is dominated by domichnion, fodinichnion and praedichnion trace fossils, and is attributed to the Skolithos and Glossifungites ichnofacies. These traces are produced mainly by decapod crustaceans, polychaetes and naticid gastropods. The sedimentological and ichnological data suggest shoreface to backshore environments with mixed tide/storm energy, and long subaerial exposures indicated by Lofer cyclothems in the lowermost part and dinosaur footprints in the upper part of the section.

Saurischian dinosaur tracks from the Upper Triassic of southern Queensland: possible evidence for Australia’s earliest sauropodomorph trackmaker

ABSTRACT Fossil footprints provide the only evidence of Triassic-aged dinosaurs in Australia. While historically several Triassic dinosaur tracksites are reported, only one specimen exists for direct study. Evidence for the Rhondda colliery (Ipswich) trackmaker, Upper Triassic Blackstone Formation as a very large-bodied Triassic predatory dinosaur is not supported by the present study because of overestimated footprint length measurements, and we question earlier interpretations that these tracks are Eubrontes-like. Instead, we recognise shared characteristics with the sauropodomorph ichnogenus Evazoum. The track morphology resembles that of Evazoum on account of the distinct shape and position of the impression of the metatarsophalangeal pad for digit IV. The mesaxony of the Blackstone Formation track is also low, but possibly slightly higher than in Evazoum, if the proportions of the digital impressions are correctly interpreted. Finally, the trackway pattern shows constant track inward rotation, a feature observed in typical Evazoum and mostly absent in Eubrontes. Therefore, we assign these Australian tracks as Evazoum ichnosp. indet. If our assessment of the Blackstone Formation tracks is correct, they provide the first and only evidence of basal sauropodomorph dinosaurs from Australia. In addition to this record, we give an overview of other reported (but lost) Australian Triassic dinosaur footprints.

Ballistic Charge Transport by Mobile Nonlinear Excitations

The developments in hyperconductivity, the loss‐free transmission of electric charge at room temperature and above, due to the ballistic transport of electric charge in crystals with quasi‐layered structure, are reported. The electric charge is carried by quodons, a type of mobile nonlinear intrinsic localized mode of lattice excitation observed as fossil tracks in layered silicates and recently by laboratory experiments. Here, ballistic means moving with minimal scattering or interaction with phonons. A test for hyperconductivity in solid materials is developed. It is based on the unique effect of short‐term continuation of transport of charge, by total internal reflection, after creation of quodons has ceased. This effect is called the slow‐quodon‐decay effect or SQD effect. So far, only layered silicates have been shown to exhibit hyperconductivity. New evidence is presented for hyperconductivity in chrysotile, a nonlayered silicate material with new results. Being a fibrous material, it is more flexible than the sheet mica phyllosilicates. It is found that quodons can also be created and carry charge in very different materials, such as polymers, but without showing hyperconductivity, because of the very short range and lifetime of quodons in those materials.

The largest theropod track site in Yunnan, China: a footprint assemblage from the Lower Jurassic Fengjiahe Formation.

Yunnan Province is famous for its diversified Lufeng vertebrate faunas containing many saurischian dinosaur remains. In addition to the body fossil record, dinosaur ichnofossils have also been discovered in Yunnan, and the number of published track sites is on the rise. We report a theropod assemblage from the Lower Jurassic Fengjiahe Formation in Xiyang, central Yunnan. It is the third report and description of dinosaur footprints from the Fengjiahe Formation, and this new track site is the largest in number of footprints for theropods in Yunnan. Over one hundred footprints are preserved on different layers of a claystone-dominated succession close to the Lower-Middle Jurassic boundary. The track area is referred to as a lacustrine shallow-water paleoenvironment. Tracks vary in size, morphology, and preservation. All are tridactyl and digitigrade, and some are identified as undertracks. The best preserved footprints were divided into three morphotypes: morphotype A (>8 cm–<21 cm) resembling Grallator; morphotype B (>27 cm–<30 cm) identified as Kayentapus xiaohebaensis; and morphotype C, an isolated footprint (39 cm) referred to the ichnogenus Kayentapus. Although footprint shape is influenced by many factors, biotic or abiotic, morphological differences among tracks such as size, divarication angles and proportions imply that at least three different kinds of theropods were visiting this site frequently. Theropod body fossils found in the surrounding area, such as Sinosaurus, turn out to be similar in body size to the projected size estimated from footprint lengths at the track site. In Yunnan, discoveries of theropod body fossils are rare. In that respect, the track record is a useful diversity indicator which can help to encompass theropod diversity patterns. Broadly speaking, large predators (five meters long or more) were uncommon in Early Jurassic ecosystems. Accordingly, large tracks are scarce on the track site, but not absent. Trackmakers of all sizes presumably coexisted in this tropical Jurassic ecosystem, and were regularly drawn to the track site in search of water or food resources.