Claw Marks Research Articles

A small sauropod trackway from the Upper Cretaceous Jindong Formation (Cenomanian), Goseong County, South Korea

In 2000, a small sauropod trackway was discovered in the Upper Cretaceous Jindong Formation (Cenomanian) at Eosin-ri, Goseong County, South Korea. This quadrupedal trackway consists of 34 very small sauropod footprints, with an average manus width of 10.0 cm and pes length of 12.8 cm, showing low heteropody (mean IPS/IMS: 1.38). The manus tracks are oval to kidney-shaped, while the pes tracks are generally subcircular to V-shaped, lacking distinct claw marks. The trackway shows a medium to wide gauge (mean PTR: 38.8%; WAP/PL: 1.18). The small footprint size and estimated trackmaker body size suggest that the trackmaker was an early juvenile titanosauriform sauropod based on the contemporaneous sauropod taxa of East Asia. Sauropod trackways reported from the Jindong Formation, including the Eosin-ri trackway, exhibit a tendency for narrower trackway gauges as pes length increases. This negative correlation between trackmaker size and trackway gauge may imply ontogenetic or behavioral variations within the same clade of sauropods or differences in gait or body plan amongst different sauropod taxa.

The Dogs Prey – A Canine Menace: A Case Report

A 13 years old male found dead with several bite marks in the body, with some 8 to 10 dogs around that area.The deceased body was brought to Mortuary, Osmania General Hospital at 03:30 PM on 19/05/2022 by the Investigation Officer and requested for postmortem examination under section 174 Criminal Procedure Code.On postmortem examination, there were multiple claw marks, avulsed lacerations, puncture wounds present all over the body, laceration of platysma and a retro-laryngeal hematoma with fracture of 6th cervical vertebrae were noted, all were suggestive of canine tooth injury. All the internal organs were pale and cause of death was given as massive haemorrhage consequent to animal bites over head, neck and trunk.

Investigating Co-occurrence among Look-alike Species: The Case of Three Bears in Northeast India

At the most basic level, the assessment of a species’ status involves knowing where it occurs. Determining the presence of rare species is difficult, and can be further confounded by the presence of a more common look-alike species. We investigated one of the few places in the world where three species of bears have been reported to co-occur at a fine scale: Balpakram National Park, Meghalaya, India. Asiatic black bears (Ursus thibetanus) are fairly common, and we sought to determine whether sun bears (Helarctos malayanus) and/or sloth bears (Melursus ursinus) also resided there. The local Garo language has words for three types of bears, and some local people reported the continued presence of a small type of bear, possibly the sun bear, but the probable extirpation of sloth bears. Because these bears look somewhat alike, local people and government forest officers could not provide convincing accounts of the presence of more than one species. We measured claw marks on climbed trees, a method used to differentiate sun bears from Asiatic black bears where both are known to occur; however, this method turned out to be unreliable for detecting sun bears where their presence was unknown because sun bear-sized marks are not distinguishable from juvenile black bears. We recommend targeted camera trapping near recent purported sightings of the other two bear species.

Differentiating Postmortem Claw Marks by the Asian Water Monitor (Kabaragoya) from Antemortem Sharp Weapon Trauma Based on the Injury Pattern

Differentiating Postmortem Claw Marks by the Asian Water Monitor (Kabaragoya) from Antemortem Sharp Weapon Trauma Based on the Injury Pattern

Crocodylian and dinosaur trace fossil assemblages from crevasse splay/levee and floodplain lake environments: middle Cenomanian Dunvegan Formation, northeast British Columbia, Canada

ABSTRACT Delta-plain strata of the Cenomanian Dunvegan Formation, in north-east British Columbia, represent anastomosed rivers that were flanked by vegetated crevasse splays, wetlands and shallow lakes. These rocks preserve a rich record of ankylosaur and ornithopod walking and wading tracks, as well as crocodylian swim traces and tracks. Analysis of depositional, erosional, and trace-making events reveals alternating phases of flooding and emergence that controlled both animal activity (walking, wading, swimming) and mud substrate consistency (firm vs. soupy), and hence fidelity of track preservation. Some tracks resemble those produced by both ankylosaurs and crocodylians, and confident attribution is difficult. The absence of tail drag marks suggests an ankylosaur trackmaker, whereas prominent claw marks might favour a crocodylian origin. Unusually large crocodylian swim traces suggest animals about 9 m, and possibly up to 12 m in length. These large traces may represent a precursor to the giant crocodylian Deinosuchus. Ankylosaur tracks are well-preserved in lake and channel-margin deposits, whereas crocodylian traces are most commonly preserved in firm muddy lake sediments that had experienced previous subaerial exposure and dewatering. Close integration of trace fossils with sedimentary and stratigraphic features makes it possible to reveal a detailed chronology of biotic and sedimentary events on palaeo-surfaces.

Current distribution of racoon (Procyon lotor) in Toyama Prefecture, Japan, inferred from claw marks of racoon and camera traps

Current distribution of racoon (<i>Procyon lotor</i>) in Toyama Prefecture, Japan, inferred from claw marks of racoon and camera traps

Landscape associations of Asiatic black bears in Kashmir Himalaya, Pakistan

The Asiatic black bear (Ursus thibetanus) is threatened throughout its range and assessed as nationally vulnerable in Pakistan. Habitat degradation and loss, illegal exploitation, and human–bear conflict are key threats to the species, but there is a lack of empirical knowledge regarding its occurrence in Pakistan. In 2012, we conducted a sign survey study to classify Asiatic black bear presence in a little studied and isolated region of the Kashmiri Mountains in Azad, Jammu and Kashmir, northern Pakistan. We compared bear presence in 5 habitat types (agriculture, forest, pasture, plantation, and scrubland) across an elevational range of 910 to 2,990 m. We used hierarchical logistic regression analysis to identify whether elevation, habitat and/or the interaction between the two explained bear presence in the region. Type of bear sign was significantly associated with some habitats, although claw marks were not associated with any habitat type. The strongest positive predictor of bear presence was the interaction between elevation and forest habitat, with greater presence (37.5%) in forest habitat at higher elevations between 1,890 and 2,855 m. The predicted likelihood of bears occurring in agriculture, plantation, and scrubland habitats was always <10%, regardless of elevation, and >30% in forest habitat. Our findings contribute to the national understanding of black bear presence and we provide recommendations for actions that support effective conservation management of the species in Pakistan.

Sun bears use 14‐year‐old previously logged forest more than primary forest in Sabah, Malaysia

AbstractSun bears (Helarctos malayanus), arguably the least‐known bear species, are endemic to Southeast Asia and are believed to be in rapid decline due to forest loss and poaching, which are severe threats across this region. It has been asserted that, unlike other forest‐dependent, omnivorous bears, sun bears are especially sensitive to changes in forest composition and canopy closure because they often feed on fruits in the canopy. We investigated habitat use of sun bears in a region of Sabah, Malaysian Borneo, containing primary forest adjacent to a 14‐yr‐old selectively logged forest. We used strip transects to quantify trees that sun bears climbed to forage or rest; these were easily recognized by distinctive claw marks. We found 1.8× the density of bear‐climbed trees in the logged vs. the primary forest. Dead wood, a home for various insects eaten by sun bears, was more common in logged forests. Except during masting years, when fruits are exceptionally abundant in this area, sun bears commonly consume termites and bees, both of which were more common in the logged forest and had a positive effect on sun bear presence. Sun bear presence was also positively associated with canopy closure, which on average was higher in primary forest, but some portions of logged forest had very high canopy cover. The logged forest had higher vegetative greenness, which up to a point was attractive to bears, but very high greenness, likely indicative of thick underbrush, appeared to be less attractive. These results indicate that previously logged areas can be valuable habitats for sun bears, providing rich supplies of food––both fruits and insects. A number of recent biodiversity surveys using camera traps have also shown high use of logged areas by sun bears, but here we connected this use to food resources. Conservation of this species is better served by appreciating its omnivorous diet and adaptiveness to varying habitats and thus recognizing the importance of preventing logged areas from deteriorating into agriculture. We warn against focusing only on saving primary forests, and predicting declines of this species from forest cutting, without considering forest regeneration.

First Pleistocene rock art found in central Europe

After well over a century of archaeological research in Drachenhöhle, the largest cave bear lair in the Alps, the first Pleistocene rock art in central Europe has been discovered deep in the cave. Two small panels of juvenile finger flutings occur together with cave bear claw marks at the only water source of the area. The site is within a few metres of the cave's large human occupation site, excavated in 1921. It is attributed to the Alpine Palaeolithic or Olschewian, a tradition of montane-adapted people of the Early Upper Palaeolithic of central Europe. The generic phenomena of finger fluting and moonmilk speleothems are discussed to provide a general context for the subject. The cave art is then described and analysed, and the previous claims for “Palaeolithic” age of other central European sites are briefly considered.

The first possible choristoderan trackway from the Lower Cretaceous Daegu Formation of South Korea and its implications on choristoderan locomotion

Here we report a new quadrupedal trackway found in the Lower Cretaceous Daegu Formation (Albian) in the vicinity of Ulsan Metropolitan City, South Korea, in 2018. A total of nine manus-pes imprints show a strong heteropodous quadrupedal trackway (length ratio is 1:3.36). Both manus and pes tracks are pentadactyl with claw marks. The manus prints rotate distinctly outward while the pes prints are nearly parallel to the direction of travel. The functional axis in manus and pes imprints suggests that the trackmaker moved along the medial side during the stroke progressions (entaxonic), indicating weight support on the inner side of the limbs. There is an indication of webbing between the pedal digits. These new tracks are assigned to Novapes ulsanensis, n. ichnogen., n. ichnosp., which are well-matched not only with foot skeletons and body size of Monjurosuchus but also the fossil record of choristoderes in East Asia, thereby N. ulsanensis could be made by a monjurosuchid-like choristoderan and represent the first possible choristoderan trackway from Asia. N. ulsanensis also suggests that semi-aquatic choristoderans were capable of walking semi-erect when moving on the ground with a similar locomotion pattern to that of crocodilians on land.

Features of Claw Marks of Masked Palm Civets: Effects of Using Claw Marks to Survey Raccoons

We examined whether masked palm civets (Paguma larvata) would leave claw marks on wooden poles by having them climb poles experimentally. We also examined the features of civet's claw marks that are generally mistaken for claw marks of racoons (Procyon lotor). The test sessions included two conditions: square and round poles of different sizes (10, 15, and 20 cm). Civets climbed wooden poles regardless of the shape and usually left short claw marks on the pole surface. The claw marks that are generally mistaken for those of a raccoon (five fingers, claw marks over 4 cm in width and over 1 cm in length) occurred in 7.6% of tracks with the 10-cm square pole, 4.1% of tracks with the 15-cm square pole, and 0.6% of tracks with the 20-cm square pole. In the round pole experiments, claw marks generally mistaken for those of a raccoon occurred in 0.0% of tracks with the 10-cm diameter pole, 0.4% of tracks with the 15-cm diameter pole, and 2.1% with 20-cm diameter pole. These results suggest that the presence of masked palm civets would have little impact on the use of claw marks to assess raccoon distribution.

Early adaptation to eolian sand dunes by basal amniotes is documented in two Pennsylvanian Grand Canyon trackways.

We report the discovery of two very early, basal-amniote fossil trackways on the same bedding plane in eolian sandstone of the Pennsylvanian Manakacha Formation in Grand Canyon, Arizona. Trackway 1, which is Chelichnus-like, we interpret to be a shallow undertrackway. It displays a distinctive, sideways-drifting, footprint pattern not previously documented in a tetrapod trackway. We interpret this pattern to record the trackmaker employing a lateral-sequence gait while diagonally ascending a slope of about 20°, thereby reducing the steepness of the ascent. Trackway 2 consists only of aligned sets of claw marks. We interpret this trackway to be a deeper undertrackway, made some hours or days later, possibly by an animal that was conspecific with Trackmaker 1, while walking directly up the slope at a speed of approximately 0.1 m/sec. These trackways are the first tetrapod tracks reported from the Manakacha Formation and the oldest in the Grand Canyon region. The narrow width of both trackways indicates that both trackmakers had relatively small femoral abduction angles and correspondingly relatively erect postures. They represent the earliest known occurrence of dunefield-dwelling amniotes―either basal reptiles or basal synapsids―thereby extending the known utilization of the desert biome by amniotes, as well as the presence of the Chelichnus ichnofacies, by at least eight million years, into the Atokan/Moscovian Age of the Pennsylvanian Epoch. The depositional setting was a coastal-plain, eolian dunefield in which tidal or wadi flooding episodically interrupted eolian processes and buried the dunes in mud.

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 &gt; 40 cm are Kayentapus -like and Eubrontes -like, and are comparable to previously described very large theropods tracks with lengths &gt; 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.

Unusual locomotion behaviour preserved within a crocodyliform trackway from the Upper Cretaceous Bayanshiree Formation of Mongolia and its palaeobiological implications

Crocodyliform tracks are reported from the Upper Cretaceous (?Cenomanian-Santonian) Bayanshiree Formation in southeastern Mongolia. Ten tracks are preserved as natural casts, forming a trackway with a quadrupedal gait pattern with a tail trail. All tracks are short and wide, and dominated by toe traces without plantar impressions. Pes tracks are characterized by four deep claw impressions and push-back marks behind them. Manus tracks have shallow claw marks and long, sub-parallel scratch marks behind. The preferential association of the scratch marks with only the distal digit impressions and irregular pattern of footfalls suggests that this trackway was made by a bottom walking and punting crocodyliform under water. This trackway represents the first crocodyliform “swim tracks” in the Late Cretaceous of Asia and the first evidence for punting behaviour of a fossil crocodyliform. The “swim tracks” can be divided into two categories such as bottom walking tracks with punting for moving somewhat more quickly and subaqueous walking tracks without punting to be associated with slower underwater speeds. The tracks show that crocodylians had adopted a bottom walking behaviour similar to extant crocodylians by Cretaceous times.

Understanding landscape and plot-scale habitat utilisation by Malayan sun bear (Helarctos malayanus) in degraded lowland forest

Malayan sun bear (Helarctos malayanus) is a forest-dependent species globally threatened by loss of suitable habitat and hunting. Understanding how sun bears utilise habitat in more degraded landscapes is increasingly important for the effective conservation of the species. We studied how landscape and plot attributes affect sun bear habitat use along a gradient of logging disturbance in a lowland forest site of Sumatra. We conducted surveys of bear claw marks to indicate sun bear habitat use at plot and landscape scales, and inform forest restoration strategies that benefit the conservation management of the species. We recorded 12 habitat features and the presence/absence of claw marks in 262 plots in four different habitat types. We reduced the number of habitat variables using Principal Components Analysis (PCA), resulting in four derived habitat factors. We used these factors in a Discriminant Analysis to refine habitat classifications of plots, and modelled presence/absence of claw marks using the PCA factors in a binary logistic regression. We inventoried tree species in a subset of randomly selected plots with claw marks alongside paired control plots with no claw marks. We compared tree community compositions in these plots using ANOSIM and SIMPER analyses. Based on claw mark signs, sun bear habitat use appeared to be non-random and was significantly associated with gradients of increasing habitat intactness, from non-forest habitat to least disturbed forest. Two PCA factors explained the probability of bears utilising a given habitat, which increased with tree biomass and decreased with understorey cover. At the plot level, tree family and species compositions were significantly different between plots without and with claw marks. The abundance and use of Olacaceae stems was significantly higher in plots with claw marks. Incorporating forest restoration strategies that enhance or increase more intact forest and the availability of key tree resources should benefit the conservation of sun bears and encourage natural forest regeneration in these degraded landscapes. We also emphasise the conservation value of degraded forest habitats for this species while ensuring bear movement and connectivity within modified landscape matrices.

A walk in the maze: variation in Late Jurassic tridactyl dinosaur tracks from the Swiss Jura Mountains (NW Switzerland).

BackgroundMinute to medium-sized (footprint length (FL) less than 30 cm) tridactyl dinosaur tracks are the most abundant in the Late Jurassic tracksites of Highway A16 (Reuchenette Formation, Kimmeridgian) in the Jura Mountains (NW Switzerland). During excavations, two morphotypes, one gracile and one robust, were identified in the field. Furthermore, two large-sized theropod ichnospecies (Megalosauripus transjuranicus and Jurabrontes curtedulensis) and an ornithopod-like morphotype (Morphotype II) have recently been described at these sites.MethodsThe quality of morphological preservation (preservation grade), the depth of the footprint, the shape variation, and the footprint proportions (FL/footprint width (FW) ratio and mesaxony) along the trackways have been analyzed using 3D models and false-color depth maps in order to determine the exact number of small to medium-sized morphotypes present in the tracksites.ResultsThe study of footprints (n = 93) recovered during the excavations has made it possible to identify and characterize the two morphotypes distinguished in the field. The gracile morphotype is mainly characterized by a high FL/FW ratio, high mesaxony, low divarication angles and clear, sharp claw marks, and phalangeal pads (2-3-4). By contrast, the robust morphotype is characterized by a lower FL/FW ratio, weaker mesaxony, slightly higher divarication angles and clear, sharp claw marks (when preserved), whereas the phalangeal pads are not clearly preserved although they might be present.DiscussionThe analysis does not allow the two morphotypes to be associated within the same morphological continuum. Thus, they cannot be extramorphological variations of similar tracks produced by a single trackmaker. Comparison of the two morphotypes with the larger morphotypes described in the formation (M. transjuranicus, J. curtedulensis, and Morphotype II) and the spatio-temporal relationships of the trackways suggest that the smaller morphotypes cannot reliably be considered as small individuals of any of the larger morphotypes. The morphometric data of some specimens of the robust morphotype (even lower values for the length/width ratio and mesaxony) suggest that more than one ichnotaxon might be represented within the robust morphotype. The features of the gracile morphotype (cf. Kalohipus isp.) are typical of “grallatorid” ichnotaxa with low mesaxony whereas those of the robust morphotype (cf. Therangospodus isp. and Therangospodus? isp.) are reminiscent of Therangospodus pandemicus. This work sheds new light on combining an analysis of variations in footprint morphology through 3D models and false-color depth maps, with the study of possible ontogenetic variations and the identification of small-sized tridactyl ichnotaxa for the description of new dinosaur tracks.

Nest existences and population of Pangolin (Manis javanica Desmarest, 1822) at the designated area of Cisokan Hydropower, West Java, Indonesia

Withaningsih S, Noorahya F, Megantara EN, Parikesit, Husodo T. 2018. Nest existences and population of Pangolin (Manis javanica Desmarest, 1822) at the designated area of Cisokan Hydropower, West Java, Indonesia. Biodiversitas 19: 153-162. Pangolin (Manis javanica) is one of the unique mammals found in Indonesia, which is categoryzed as protected species. However, the scientific information regarding with the population and distribution of this species is still low. Therefore, the study aimed to estimate the total population, distribution, and potential threat to Pangolin in the designated area of Cisokan Hydropower, West Java. Study was conducted using three methods; direct observation (survey) of animal signs (nest, footprint, tail print, claw marks, and feed left over), camera traps placement, and semi-structure interviews. The result shows that the active and abandoned (inactive) nests were found within the study site, and could be classified as tree nest, rock nest, and ground nest. The total population of Pangolin in Cisokan hydropower project site was estimated around 6-20 individuals. This population was distributed in five different areas; first areas were Pasir Gagak, Cigintung, Batu Nunggul, and Batu Sahulu; second area was Batu Wulung; third areas were Curug Japarana and Curug Walet; fourth areas were Hutan Gowek and Cadas Gantung; fifth area was Pongpok. The potential threats experienced by Pangolin were from illegal hunting activity and habitat fragmentation caused by infrastructure development and field clearing for crops plantation.

Trackways of the American Crocodile (Crocodylus acutus) in Northwestern Costa Rica: Implications for Crocodylian Ichnology

ABSTRACTWe documented trackways of free-living Crocodylus acutus on beaches at the mouths of Tamarindo and Ventanas estuaries, Costa Rica. Our crocodiles had estimated total lengths of 1–3 meters or more. Manus prints have five digits, with digits I–III bearing claw marks. Pes prints have four digits, with claw marks on digits I–III. The pes is plantigrade. Claws generally dig into the substrate. Apart from claw marks, digit I and the heel of the pes are usually the most deeply impressed parts of footprints. Trackways are wide-gauge. Pes prints are usually positioned just behind ipsilateral manus prints of the same set and may overlap them. Manus and pes prints angle slightly outward with respect to the crocodile's direction of movement. Claw-bearing digits of both the manus and pes may create curved, concave-toward-the-midline drag marks as the autopodium is protracted. The tail mark varies in depth and clarity, and in shape from nearly linear to markedly sinuous. Sometimes the tail mark hugs the trackway midline, but sometimes it is closer to, or even cuts across, prints of one side. American crocodile footprints and trackways are similar to those observed in other extant crocodylian species, indicating substantial trackway conservatism across the group.

Megalosauripus transjuranicus ichnosp. nov. A new Late Jurassic theropod ichnotaxon from NW Switzerland and implications for tridactyl dinosaur ichnology and ichnotaxomy.

A new ichnospecies of a large theropod dinosaur, Megalosauripus transjuranicus, is described from the Reuchenette Formation (Early–Late Kimmeridgian, Late Jurassic) of NW Switzerland. It is based on very well-preserved and morphologically-distinct tracks (impressions) and several trackways, including different preservational types from different tracksites and horizons. All trackways were excavated along federal Highway A16 near Courtedoux (Canton Jura) and systematically documented in the field including orthophotos and laserscans. The best-preserved tracks were recovered and additional tracks were casted. Megalosauripus transjuranicus is characterized by tridactyl tracks with clear claw and digital pad impressions, and notably an exceptionally large and round first phalangeal pad on the fourth digit (PIV1) that is connected to digit IV and forms the round heel area. Due to this combination of features, M. transjuranicus clearly is of theropod (and not ornithopod) origin. M. transjuranicus is compared to other Megalosauripus tracks and similar ichnotaxa and other unassigned tracks from the Early Jurassic to Early Cretaceous. It is clearly different from other ichnogenera assigned to large theropods such as Eubrontes–Grallator from the Late Triassic and Early Jurassic or Megalosauripus–Megalosauropus–Bueckeburgichnus and Therangospodus tracks from the Late Jurassic and Early Cretaceous. A second tridactyl morphotype (called Morphotype II) is different from Megalosauripus transjuranicus in being subsymmetric, longer than wide (sometimes almost as wide as long), with blunt toe impressions and no evidence for discrete phalangeal pad and claw marks. Some Morphotype II tracks are found in trackways that are assigned to M. transjuranicus, to M.? transjuranicus or M. cf. transjuranicus indicating that some Morphotype II tracks are intra-trackway preservational variants of a morphological continuum of Megalosauripus transjuranicus. On the other hand, several up to 40 steps long trackways very consistently present Morphotype II features (notably blunt digits) and do not exhibit any of the features that are typical for Megalosauripus (notably phalangeal pads). Therefore, it is not very likely that these tracks are preservational variants of Megalosauripus transjuranicus or Megalosauripus isp. These trackways are interpreted to have been left by an ornithopod dinosaur. The high frequency of large theropod tracks in tidal-flat deposits of the Jura carbonate platform, associated on single ichnoassemblages with minute to medium-sized tridactyl and tiny to large sauropod tracks has important implications for the dinosaur community and for paleoenvironmental and paleogeographical reconstructions. As with most other known occurrences of Megalosauripus tracks, M. transjuranicus is found in coastal settings, which may reflect the preference of their theropod trackmakers for expanded carbonate flats where food was abundant.

Rhynchosauroides Footprint Variability in a Muschelkalk Detrital Interval (Late Anisian–Middle Ladinian) from the Catalan Basin (NE Iberian Peninsula)

ABSTRACTThe Middle Triassic successions of coastal and distal alluvial systems are often characterized by the presence of the tetrapod ichnotaxon Rhynchosauroides. Nevertheless, few studies paid attention on the paleoenvironmental implications of this widely distributed ichnogenus. The finding of a new Rhynchosauroides-dominated tracksite opens the window to the use of such footprints in paleoenvironmental studies. The tracksite is located in the active quarry of Pedrera de Can Sallent, at Castellar del Vallès (Catalan Basin, NE Iberian Peninsula). The footprints were recovered from the Middle Muschelkalk detrital unit, composed of a claystone-sandstone-gypsum succession from a sabkha setting of late Anisian-middle Ladinian age. This unit was deposited during a short regression interval within the main Middle Triassic transgression represented by the Muschelkalk facies. The ichnoassociation is composed of Rhynchosauroides isp., and a single, partially preserved, undetermined large footprint. Among Rhynchosauroides specimens, three different preservation states were recognized, corresponding to substrates in (1) subaqueous conditions (surfaces with scarce, deformed, and deeply impressed ichnites), (2) occasionally flooded (mostly trampled surfaces, footprints commonly well preserved), and (3) subaerial exposition (surfaces with few footprints, sometimes corresponding to faint impressions or only preserved by claw marks). The footprint morphological variations of Rhynchosauroides are correlated to substrate rheology and further to the environmental conditions. Rhynchosauroides is a characteristic morphotype that often dominates in the Anisian-Ladinian coastal and distal alluvial settings of several European tracksites. Therefore, these ichnoassociations in such environments, awaiting further detailed analyses, may constitute a distinct ichnocoenosis.