Dinosaur Tracks Research Articles

Demographic interpretation of colossal theropod footprints discoveries from Imilchil (Mid-Jurassic, Central High Atlas, Morocco)

Among the footprints found in Imilchil (Central High Atlas, Morocco) are two large ichnites that we characterize as “colossal” to distinguish them from the “giant” theropod footprints in the usage of other authors. These discoveries add to the scarce record of very large footprints, and contribute to the knowledge of the spatial-temporal distribution of such colossal footprints. We classify the sites with dinosaur tracks by their geographic location and age in Temporal Geographical Circumscriptions (TGCs) that lead to the separation of nine TGCs containing colossal theropod tracks. We analyzed the total content of described theropod footprints of the nine TGCs to relate the colossal footprint populations by size. This analysis, which extends from the Middle Jurassic to the Upper Cretaceous, distributes the colossal footprints geographically in a limited (non-random) way. As a consequence of the above, we hypothesze that their distribution may be zonal possibly due to latitude, climate or geographical barriers. localized in different TGCs according to the geological period.

How to verify fossil tracks: the first record of dinosaurs from Palestine

ABSTRACT The identification of presumed tetrapod tracks is not always unequivocal. Other sedimentary structures have been repeatedly mistaken for tracks, including other trace fossils such as arthropod tracks, burrows and fish feeding traces; erosional features; and human-made traces. We here review instances of difficult, ambiguous, or controversial cases that have been discussed in the literature. We then discuss four main criteria for the verification of tetrapod tracks: (1) preservation of regular trackway morphology, (2) preservation of track morphology, (3) deformation structures (best seen in cross-section) and (4) the temporal or environmental context. Of these criteria, criterion 1 is the most unambiguous and has rarely been challenged. We apply these criteria to a new site located within the city of Al-Bireh, Palestine, which belongs to the Lower Cretaceous (Albian) Soreq Formation. The site preserves a surface with many indistinct depressions that lack anatomical detail. Two unequivocal trackways are identified per criterion 1, demonstrating the first known occurrence of dinosaur fossils in Palestine. The tracksite is part of the late Lower Cretaceous carbonate platform of the eastern Levant, demonstrating temporal emergence of the platform above sea level and a connection to the mainland.

Lacertoid tracks from the Botucatu Formation (Lower Cretaceous) with different locomotor behaviors: A new trackmaker with novel paleoecological implications

The Botucatu Formation (Paraná Basin) is an eolian deposit that represents an extensive paleoerg that existed in the south-central Gondwana during the Early Cretaceous. The fossil record of the unit is almost exclusively constituted of ichnofossils, including numerous tracks and burrows of vertebrates and invertebrates. The greatest trace fossil diversity of the Botucatu Formation is reported at the Ouro ichnosite, located in the Araraquara municipality region, São Paulo State, Brazil. This site comprises a faunal-rich setting of greater humidity in the ancient desert. In this work, a new footprint morphotype is reported for the Ouro ichnosite. Five trackways including tracks with an elongated anteroposterior axis associated with tail drag marks are described. The morphology of the autopodia and geometry of the trackways indicate an affinity with a lizard-like trackmaker. Furthermore, at least three different modes of locomotion were recognized: a typical walking gait, a pause-walking gait, and sideways drifting. The current report suggests Lepidosauria may have inhabited the ancient Botucatu desert, a group never reported before in this geological context. This finding expands the knowledge about the Botucatu Formation paleofauna and adds more complexity to its ecological network. Squamata and Sphenodontia are plausible candidates to have produced the described fossil tracks.

Editorial

Editorial

New ornithopod tracks from the Lower Cretaceous El Castellar Formation (Spain): Implications for track preservation and evolution of ornithopod footprints

Dinosaur tracks have been identified in several Upper Jurassic-Lower Cretaceous sedimentary units across the Maestrazgo Basin in eastern Iberia, which are preserved in a variety of transitional and continental paleoenvironments. Here, we described the lower Barremian San Benón tracksite with the first occurrence of clear dinosaur tracks in the El Castellar Formation within the Galve subbasin. This palustrine-lacustrine formation has yielded a rich osteological record although dinosaur tracks are notably scarce. The new footprints represent an uncommon case of dinosaur track preservation since the site has yielded several non contemporary tracks (part of different ichnoassemblages) preserved as carbonate casts at the base of a limestone bed forming a composite ichnofabric. The tracksite shows a complex history of sedimentation, track production and preservation linked to the lake level variations. The ornithopod tracks are identified to belong to the ornithopod ichnogenus Caririchnium , concretely to the ichnospecies C. magnificum. The studied tracks represent the oldest occurrence of this ichnotaxa in the Maestrazgo Basin and are coherent with other coeval (or almost coeval) occurrences in the Iberian Peninsula. The presence of C. magnificum in the El Castellar Formation fills a gap between the oldest (Tithonian-early Valanginian?) and younger (Barremian) occurrences of ornithopod tracks within the Maestrazgo Basin, being one of the most complete successions of ornithopod tracks in Europe. Interestingly, the underlaying formations have ichnoassemblages with Dinehichnus -like and Iguanodontipus -like tracks, whereas Caririchnium is mainly found in El Castellar Formation and other Barremian units. These changes in the ichnoassemblages reflect the ornithopod faunal changes shown by osteological data in the Iberian Peninsula recording a Late Jurassic-earliest Cretaceous stage dominated by basal iguanodontians followed by an Early Cretaceous stage with abundance of more derived and large-sized iguanodontians. • First occurrence of clear dinosaur tracks in the lacustrine El Castellar Fm in the Galve subbasin. • Uncommon case of dinosaur footprint preservation as casts in carbonates. • Complex history of sedimentation and track production linked to the lake level. • First occurrence of Caririchnium magnificum in the Maestrazgo Basin (Iberian Peninsula). • Ornithopod faunal changes during the Late Jurassic/Early Cretaceous.

Dinosaur Tracks from the Lower Jurassic Lufeng Formation of Northern Central Yunnan, China

An increasing number of theropod-dominated tracksites have been reported from the Jurassic and Cretaceous of China. These include a significant number from the Lower Jurassic of the Lufeng Basin, famous for its Lufengosaurus fauna and known for a typical Lower Jurassic globally-distributed tetrapod footprint biochron. Here we report another localized theropod track occurrence regular of various scattered tracksites from the Lufeng Formation. The tracks are medium-sized tridactyl tracks from the basal member of the Zhangjia'ao Member, Lufeng Formation which shows an unusually wide divarication between the traces of digits III and IV, which suggest several possible interpretations.

Dinosaur Track from the Jurassic Xiahuayuan Formation of Northern China

An isolated but moderately well-preserved theropod track from the coal-bearing strata of the Zhangjiakou City region of Hebei Province was reported to have originated from the Xiahuayuan Formation, which is considered Middle Jurassic in age. Although the track has a wide divarication angle and length-width ratio reminiscent of Cretaceous tracks like Magnoavipes, it would be speculative to apply this Identification based on a single track. Therefore, it is considered most likely to be a preservational variant of Kayentapus, in which the heel trace is lacking. Kayentapus is widely known from the Lower Jurassic of China. This is the first report of a track or any vertebrate fossil from the Middle Jurassic of this region of Hebei Province, China.

A Preliminary Review of Dinosaur Track Assemblages from the Tuchengzi Formation in North China

In northern China, mainly within Western Liaoning, Northern Hebei and Beijing, vertebrate skeletons from the Tuchengzi Formation (Upper Jurassic to Lower Cretaceous) are scarce. However, a large number of new dinosaur track discoveries have made in past 10 years. So far, a total of 19 dinosaur track sites have been found in the Tuchengzi Formation, collectively containing 2,637 individual tracks and representing at least 2,091 trackmakers. This track record has become an important sample for understanding the Tuchengzi dinosaur fauna. The abundant Tuchengzi track record includes six non-avian theropod ichnogenera (Asianopodus, Eubrontes, Grallator, Menglongipus, Therangospodus, and Velociraptorichnus), three bird ichnogenera (Aquatilavipes, Pullornipes, and Koreanaornis), two sauropod ichnogenera (Brontopodus and cf. Parabrontopodus isp.), and a possible ornithopod ichnogenus (cf. Dinehichnu). This assemblage is saurischian-dominated, which is consistent with most Jurassic and Cretaceous track sites in China. The presence of deinonychosaurian tracks is consistent with the rich skeletal record from the Yanliao Biota or Jehol Biota, and the bird tracks are consistent with the record of shorebirds in Jehol Biota. The existence of ornithopod tracks is doubtful and needs further discoveries to be confirmed.

What is Stance Phase On Deformable Substrates?

The stance phase of walking is when forces are applied to the environment to support, propel, and maneuver the body. Unlike solid surfaces, deformable substrates yield under load, allowing the foot to sink to varying degrees. For bipedal birds and their dinosaurian ancestors, a shared response to walking on these substrates has been identified in the looping path the digits follow underground. Because a volume of substrate preserves a 3-D record of stance phase in the form of footprints or tracks, understanding how the bipedal stride cycle relates to this looping motion is critical for building a track-based framework for the study of walking in extinct taxa. Here we used biplanar X-ray imaging to record and analyze 161 stance phases from 81 trials of three Helmeted Guineafowl (Numida meleagris) walking on radiolucent substrates of different consistency (solid, dry granular, firm to semi-liquid muds). Across all substrates, the feet sank to a range of depths up to 78% of hip height. With increasing substrate hydration, the majority of foot motion shifted from above to below ground. Walking kinematics sampled across all stride cycles revealed six sequential gait-based events originating from both feet, conserved throughout the spectrum of substrate consistencies during normal alternating walking. On all substrates that yielded, five sub-phases of gait were drawn out in space and formed a loop of varying shape. We describe the two-footed coordination and weight distribution that likely contributed to the observed looping patterns of an individual foot. Given such complex subsurface foot motion during normal alternating walking and some atypical walking behaviors, we discuss the definition of "stance phase" on deformable substrates. We also discuss implications of the gait-based origins of subsurface looping on the interpretation of locomotory information preserved in fossil dinosaur tracks.

Theropod and ornithischian dinosaur track assemblages from Middle to ?Late Jurassic deposits of the Central High Atlas, Morocco

ABSTRACT Tridactyl theropod and ornithischian dinosaur tracks and trackways from Imilchil and Isli formations (Middle–?Late Jurassic, Bajocian–?) of the central High Atlas region (Morocco) are described. The Imilchil Formationconsists of brackish marine-continental deposits, and the Isli Formation is a continental red-bed succession. Considering numerous new footprint discoveries, including recently described Polyonyx sauropod trackways, tridactyl dinosaur tracks from the Imilchil-Tounfite region are revised. Dominating are theropod footprints resembling the ichnogenus Changpeipus and known from Lower-Middle Jurassic deposits of China. Other theropod ichnotaxa are Trisauropodiscus isp., cf. Wildeichnus isp.,Carmelopodus isp., Megalosauripus isp., Kayentapus isp. and an indeterminate small grallatorid. Ornithischians are represented by small indeterminate ornithischian tracks, large ornithischian footprints cf. Stegopodus isp. and a large indeterminate ornithopod form. Makers of the small theropod trackswere small coelurosaurs or basal tetanurans, larger forms belong toceratosaurs, megalosauroids, allosauroids or tyrannosauroids. Ornithischian tracks suggest dryomorphs, iguanodontians and thyreophorans as producers. Together with crocodylomorph and pterosaur tracks, invertebrate traces and plants, the Imilchil and Isli formations document a flourishing ecosystem and dinosaur habitat. Remarkable is the presence of Changpeipus theropod tracks known from abundant occurrences in East Asia. This suggests an exchange of dinosaur faunas between this region and northern Africa during the Middle Jurassic.

Theropod and other dinosaurian tracks from the upper Lower Cretaceous of northeastern China: Overlooked Fuxin Biota records reinvestigated

Dinosaur tracks have been known and reported sporadically from the coal-bearing beds of the Fuxin Formation (upper Aptian–Albian, upper Lower Cretaceous) of Liaoning Province, northeastern China for some time but have not been described in detail. Here available material is illustrated suggesting a diversity of theropod track morphotypes, including small grallatorid, eubrontid and possible Gigandipus-like forms, a Magnoavipes-like form and an isolated small ornithopod track. Some of the tracks show the characteristic distortion of flattened footprints. The ichnofauna supplements our knowledge of the Fuxin Biota by adding a more diverse dinosaur fauna, indicated by the footprint record.

Digitising Svalbard’s Geology: the Festningen Digital Outcrop Model

The renowned Festningen section in the outer part of Isfjorden, western Spitsbergen, offers a c. 7 km-long nearly continuous stratigraphic section of Lower Carboniferous to Cenozoic strata, spanning nearly 300 million years of geological history. Tectonic deformation associated with the Paleogene West-Spitsbergen-Fold-and-Thrust belt tilted the strata to near-vertical, allowing easy access to the section along the shoreline. The Festningen section is a regionally important stratigraphic reference profile, and thus a key locality for any geologist visiting Svalbard. The lithology variations, dinosaur footprints, and the many fossil groups, record more than 300 million years of continental drift, climate change, and sea level variations. In addition, the Festningen section is the only natural geoscientific monument protected by law (i.e. geotope) in Svalbard. In this contribution, we present a digital outcrop model (DOM) of the Festningen section processed from 3762 drone photographs. The resulting high-resolution model offers detail down to 7.01 mm, covers an area of 0.8 km2 and can be freely accessed via the Svalbox database. Through Svalbox, we also put the Festningen model in a regional geological context by comparing it to nearby offshore seismic, exploration boreholes penetrating the same stratigraphy and publications on the deep-time paleoclimate trends recorded at Festningen.

Ostracoda (Crustacea) from the Lower Jurassic of northeastern Thailand: stratigraphic and paleoenvironmental implications

Freshwater ostracods were recovered from limestone strata belonging to the Nam Phong Formation exposed at Ban Non Tum section in Chaiyaphum Province, northeastern Thailand. The examined rocks were collected above the oldest known dinosaur footprints site in Thailand. All recovered ostracods belong to the Superfamily Darwinuloidea and were attributed to three species: Suchonellina sarytirmensis (Sharapova) in Mandelstam, 1947, Suchonellina. sp. A and Suchonellina sp. B. The ostracods represent the first known record of Jurassic darwinuloideans in Southeast Asia. The ostracod assemblage and microfacies are indicative of deposition in a shallow and low energy fluvio-lacustrine regime.

Concurrent evidence from ichnology and anatomy: the scelidotheriine ground sloths (Xenarthra, Folivora) from the Pleistocene of Argentina

ABSTRACT In the fossil record of South America, both ground sloths and their tracks are well known. However, most tracks described were assignable to megatherians and mylodontids, while tracks assignable to scelidotheriines show a very scarce record. In this contribution, we present new records of fossil tracks assignable to scelidotheriines and review and expand the original description of the ichnotaxon Acugnaichnum dorregoensis. In addition, we explored the correlation between track features and limb morphology, finding that the tracks can help to better understand the posture and function of scelidotheriine limbs. Features of the handprint suggest that these ground sloths would not rest hands in the substrate by its palmar aspect, but on the knuckles or its lateral aspect, similar to the extant giant and lesser anteaters. Concerning the foot tracks, their features indicate that digits V and IV rested on the substrate in a different orientation than the digit III, whose large ungual phalanx provided additional support by resting of its lateral side, which is biomechanically coherent with the stability of the foot. In addition, some kind of soft tissue cushion would be present below the main arch of the foot. Evidence for locomotion style and bipedalism is discussed.

Estimating Gaits of an Ancient Crocodile-Line Archosaur Through Trajectory Optimization, With Comparison to Fossil Trackways.

Fossil trackways provide a glimpse into the behavior of extinct animals. However, while providing information of the trackmaker size, stride, and even speed, the actual gait of the organism can be ambiguous. This is especially true of quadrupedal animals, where disparate gaits can have similar trackway patterns. Here, predictive simulation using trajectory optimization can help distinguish gaits used by trackmakers. First, we demonstrated that a planar, five-link quadrupedal biomechanical model can generate the qualitative trackway patterns made by domestic dogs, although a systematic error emerges in the track phase (relative distance between ipsilateral pes and manus prints). Next, we used trackway dimensions as inputs to a model of Batrachotomus kupferzellensis, a long-limbed, crocodile-line archosaur (clade Pseudosuchia) from the Middle Triassic of Germany. We found energetically optimal gaits and compared their predicted track phases to those of fossil trackways of Isochirotherium and Brachychirotherium. The optimal results agree with trackways at slow speeds but differ at faster speeds. However, all simulations point to a gait transition around a non-dimensional speed of 0.4 and another at 1.0. The trackways likewise exhibit stark differences in the track phase at these speeds. In all cases, including when simulations are constrained to the fossil track phase, the optimal simulations after the first gait transition do not correspond to a trot, as often used by living crocodiles. Instead, they are a diagonal sequence gait similar to the slow tölt of Icelandic horses. This is the first evidence that extinct pseudosuchians may have exhibited different gaits than their modern relatives and of a gait transition in an extinct pseudosuchian. The results of this analysis highlight areas where the models can be improved to generate more reliable predictions for fossil data while also showcasing how simple models can generate insights about the behavior of extinct animals.

The dinosaur tracks of Tyrants Aisle: An Upper Cretaceous ichnofauna from Unit 4 of the Wapiti Formation (upper Campanian), Alberta, Canada.

The Wapiti Formation of northwest Alberta and northeast British Columbia, Canada, preserves an Upper Cretaceous terrestrial vertebrate fauna that is latitudinally situated between those documented further north in Alaska and those from southern Alberta and the contiguous U.S.A. Therefore, the Wapiti Formation is important for identifying broad patterns in vertebrate ecology, diversity, and distribution across Laramidia during the latest Cretaceous. Tracksites are especially useful as they provide a range of palaeoecological, palaeoenvironmental, and behavioural data that are complementary to the skeletal record. Here, we describe the Tyrants Aisle locality, the largest in-situ tracksite known from the Wapiti Formation. The site occurs in the lower part of Unit 4 of the formation (~72.5 Ma, upper Campanian), exposed along the southern bank of the Redwillow River. More than 100 tracks are documented across at least three distinct track-bearing layers, which were deposited on an alluvial floodplain. Hadrosaurid tracks are most abundant, and are referable to Hadrosauropodus based on track width exceeding track length, broad digits, and rounded or bilobed heel margins. We suggest the hadrosaurid trackmaker was Edmontosaurus regalis based on stratigraphic context. Tyrannosaurids, probable troodontids, possible ornithomimids, and possible azhdarchid pterosaurs represent minor but notable elements of the ichnofauna, as the latter is unknown from skeletal remains within the Wapiti Formation, and all others are poorly represented. Possible social behaviour is inferred for some of the hadrosaurid and small theropod-like trackmakers based on trackway alignment, suitable spacing and consistent preservation. On a broad taxonomic level (i.e., family or above), ichnofaunal compositions indicate that hadrosaurids were palaeoecologically dominant across Laramidia during the late Campanian within both high-and low-latitude deposits, although the role of depositional environment requires further testing.

Geothematic map of the Altamura dinosaur tracksite (early Campanian, Apulia, southern Italy)

In 2019 a multidisciplinary study of the Altamura dinosaur tracksite (Apulia, southern Italy; early Campanian) was carried out to meticulously document its geological and palaeontological features. The goal was to pave the way for projects aimed at long-term conservation and valorisation of the geo-palaeontological heritage. For this purpose, a mapping of the whole track-bearing surface was performed, which led to the production of the first geothematic map (1:200) of the whole ichnosite. During the field activities, the surface was subdivided into 34 distinct sectors. For each sector, the work started with accurate manual and mechanical cleaning of the surface (industrial vacuum cleaner). The ichnological survey was carried out using standard methods (interpretative drawings with chalks to highlight outline and morphological features of each track). This approach was combined with close-range photogrammetry to obtain detailed 3D models of the best-preserved specimens. Finally, each sector was surveyed through aerial-based photogrammetry by means of sUAS (small Unmanned Aerial System). The aerial survey allowed us to gain a high-resolution and georeferenced orthophoto processed by using specific software. The field ichnological drawings occurring on each orthophoto were then traced and vectorised. The final step was the overlapping of each digitised sector and the processing of the tracksite map. The products of our study (geothematic map and 3D models of dinosaur tracks) highlight the extraordinary richness of the Altamura tracksite (26,000 footprints and 12 distinct trackways), confirming the high impact of new methodologies (close-range and aerial- based photogrammetry) as useful tools both for ichnological studies and future activities of public fruition of the geosite.

Possible Pleistocene hominin tracks from South Africa’s west coast

Two probable tracks have been identified on the ceiling of a small overhang in the Pleistocene Langebaan Formation on South Africa’s west coast. They may have been made by a hominin trackmaker. They appear to have been registered at walking speed on a level, sandy dune substrate. Three tracks, attributed to Homo sapiens, were previously identified near Langebaan in 1995, and were popularly labelled ‘Eve’s Footprints’. The new identification of possible hominin tracks near Langebaan is the second from South Africa’s west coast. This discovery adds to the sparse but growing global record of possible hominin tracks preserved in aeolianites.Significance: Two probable fossil tracks have been identified on the ceiling of an overhang near Langebaan. The tracks may have been made by a human walking on a level dune surface during the Pleistocene. This discovery is the second of its kind on the west coast, and complements the 1995 identification near Langebaan of Pleistocene fossil tracks attributed to humans.

Defining the Bemaraha megatracksite: an update on dinosaur ichnology in Madagascar

Abstract The Bemaraha Formation preserves a unique and abundant record of dinosaur footprints, the only occurrence of this type known from Madagascar. Theropod and sauropod tracks occur in Middle Jurassic strata and form an important record from this otherwise poorly documented time interval. Here we report on 18 new tracksites, raising the total number of known localities in the Bemaraha to 31. The majority of these sites occur at the same stratigraphic level that can be traced over an area of at least 30 km 2 , which makes it one of the most laterally extensive occurrences of dinosaur tracks on record in the Southern Hemisphere. Dinosaur tracks are restricted to a few bedding surfaces representing times of sea-level lowstand within a normally marine environment. Theropod tracks are by far more abundant than sauropod tracks and typically are orientated towards the palaeocoastline. This pattern is interpreted as evidence of a short-scale migration between feeding and resting grounds. The Bemaraha Formation thus allows a rare glimpse into dinosaur behaviour in a marginal-marine environment of Jurassic age.

Introduction to teaching science with three-dimensional images of dinosaur footprints from Cristo Rey, New Mexico

Abstract. In this paper we discuss the use of three-dimensional (3-D) imagery and virtual field trips to teach pre-university and non-major university geoscience courses. In particular, 3-D PDF (Portable Document Format) files can be used to either prepare students for or completely replace a field trip when logistical problems make the actual trip too difficult to be effective or when some students need an alternative accommodation. Three-dimensional images can replace or supplement classroom activities, such as the identification of rocks and minerals from hand samples or the identification of geologic structures from 2-D photographs and limited field observations. Students can also become involved in data collection and processing to further their understanding of photogrammetry and visualization. The use of 3-D imagery can make additional time available to instructors to cover more advanced topics and teach students more about the role of science in geologic research. We use an example from Cristo Rey, New Mexico, where dinosaur footprints and tracks are present but difficult to see in many cases, and they are often in places that are hard to access for many people. At this site, approximately 10 000 photographs were collected and processed as 3-D images to show one approximately 72 m2 area of known footprints. However, we also conducted some very simple digital manipulations of the images that allowed us to identify new footprints and tracks that were not apparent when viewed in the field. The photographs and 3-D images have been donated to the Insights El Paso Science Center (denoted Insights Museum herein) that owns the fossil site, and they are now being used to develop educational materials and lessons for the nearby communities.