Drag Marks Research Articles

Assessing predator–prey interactions during the Late Triassic of India from bite marks on Hyperodapedon (Archosauromorpha, Rhynchosauria)

ABSTRACT Multiple cranial and mandibular remains of Hyperodapedon huxleyi known from the lower part of the Upper Triassic Maleri Formation were examined to reveal distinct bite marks. These were identified as punctures based on their circular or oval or elliptical outline and deep penetration into the cortical bone, and were found associated with several bone-damaging features such as radiating fractures, serrated boundaries, and collapsed bony surface. In addition, bite traces or drag marks in the form of parallel grooves with U-shaped cross sections are identified. The bite marks are compared with dental morphology of varied Late Triassic carnivores of India, and the probable producers are suggested to be phytosaurs and dinosauriforms. The Maleri trophic structure or food web is reconstructed to reveal interconnectedness between different animal groups, unconfined feeding habits of the animals where the predators were inclined towards opportunistic feeding rather than a niche-based dietary habit. The study highlights the significance of bite marks in the reconstruction of ancient paleoecosystems.

Coexistence of Indian Pangolin Manis crassicaudata (Geoffroy, 1803) (Mammalia: Pholidota: Manidae) and Indian Crested Porcupine Hystrix indica (Kerr, 1792) (Mammalia: Rodentia: Hystricidae) in Purulia District, West Bengal, India

The Indian Pangolin Manis crassicaudata and the Indian Crested Porcupine Hystrix indica are subject to extensive poaching in Purulia District (West Bengal, India), diminishing their populations, and making the study difficult. Applying methodologies that include local sightings, field observations, camera trapping, and quadrate analysis, these species were observed to co-occur in rocky cavities in Ajodhya hills at several locations. Evidence for this included fresh pangolin tail drag marks, claw prints, footprints, scales, porcupine quills, teeth marks, and faecal matter in the same locations within the study area. Quadrate analysis showed that the trees housing the target prey species of the Indian Pangolin as well as the trees bearing fruits favoured by the Indian Crested Porcupine, occurred at maximum frequency within the Quadrate area. We hypothesise that pangolins and porcupines co-occupy rocky cavities for protection from poachers, who can easily break into more typical burrows and set traps in front of them. This may be an example of adaption to poaching, which demonstrates the necessity of conservation measures to alleviate severe anthropogenic pressure.

Crocodile tail traces and dinosaur footprints. Bathonian?- Callovian. Imilchil. High Central Atlas. Morocco

Three types of ichnites from a new site discovered in Imilchil were studied and described. The structures of pes and manus prints and tail traces of tetrapods provide data to separate: real ichnites (theropod footprints and crocodile tail drag marks); and sauropod’ subtraces. Most of the theropod footprints are deformed by collapse of their walls, the sauropod subtraces show the strong deformation of about ten well-stratified sedimentary levels. The surface on which we can see theropod and crocodile ichnites is the tracking surface, i. e. the original surface on which they were printed.

Turtle tracks from the middle Jurassic Yaopo formation in Beijing, China

ABSTRACT This study introduces new discoveries of fossil footprints from the Middle Jurassic Yaopo Formation in Beijing, China, marking the first reptile fossils that have been discovered in this formation. The two small footprints with parallel digits and drag marks suggest they were made by tetrapods moving through water. While there are similarities to crocodylian and pterosaur tracks, the evaluation suggests that turtles are the most likely trace-makers. If correct, the Yaopo Formation footprints are likely made by xinjiangchelyids, given their dominance in Asian freshwater ecosystems during the Late Jurassic and their widespread distribution in Late Jurassic China. Sichuanchelyids, Bashuchelyidae, and Hongkongochelys are less likely candidates due to their limited temporal and geographical distribution. This finding adds to the growing body of evidence on the evolution and ecology of turtles in Asia during the Late Jurassic period. These new findings offer important insights into the behaviour and spatiotemporal occurrence of these ancient reptiles and expand our understanding of their role in prehistoric aquatic ecosystems.

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.

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.

A new look at Crocodylopodus meijidei: implications for crocodylomorph locomotion

ABSTRACT A review of the type material of the crocodylomorph ichnotaxon Crocodylopodus meijidei Fuentes Vidarte and Meijide Calvo, 2001 from the Berriasian of Spain is carried out. The review allows a better characterization of this type ichnotaxon and provides interesting new data on the candidate trackmakers and especially on their locomotion. Three different size classes possibly related to different ontogenetic states or sexual dimorphism of the same small- to medium-sized crocodylomorph trackmaker are distinguished. Morphological differences within the sample such as digital impression lengths might be a consequence of differences in allometric growth, assuming similarities with extant crocodylians. Other differences are a consequence of variation in the morphological quality and mode of preservation across the sample. Some trackway features (intermediate-gauge trackways with high pace angulation, absence of tail, belly or drag marks) indicate the trackmakers, presumed neosuchian crocodylomorphs, were walking in a ‘high-walk’ mode with a semi-erect posture at a moderate speed. The trackmaker may have walked with more erect limb posture and with the center of mass located more anteriorly than occurs in extant species, albeit not as erect as quadrupedal animals such as mammals or other extinct archosaurs including trackmakers of other crocodylomorph ichnotaxa (e.g., Batrachopus).

A Late Triassic aquatic community: Undichna-like and related swimming traces from a freshwater pond in the lower Elliot Formation of South Africa

Swimming and subaqueous traces and trails are reported, for the first time, from a freshwater pond community in the middle Norian lower Elliot Formation (lEF) in the main Karoo Basin of South Africa. These ichnofossils, associated abiotic tool marks, and sedimentary structures are preserved on the upper bedding plane of a fine- to medium-grained sandstone that is overlain by laminated mudstones. The assessment of the relationship between the sedimentology and ichnology of this ichnosite reveals a unique perspective into a Late Triassic ecosystem. Here, a brief time window showcases events ranging from the abandonment of a river channel, to the initiation of a floodplain pond, and its subsequent infilling by silty sediments. The trace fossil assemblages, their cross-cutting relationships and the sedimentological evidence suggest that several generations of traces formed during the silting up of this floodplain pond, a palaeoenvironment infrequently documented in the lEF. Some trails are described as similar to Undichna Anderson 1976, and can be attributed to small, swimming freshwater fish. Didactyl tracks with Grallator/Anchisauripus-like affinities are associated with both sickle-shaped digit drag marks and 3–8 cm long disorderly striations showing variable morphology (e.g., narrowly incised, straight to slightly sinuous, V-shaped grooves). Their preservation indicates wading and subaqueous behaviour of tetrapods. Other traces range from semi-circular impressions of unknown affinity to unique, yet indistinct, < 2-cm-long, partially preserved ichnofossils with three (or possibly four) slender digit impressions. Together these ichnofossils provide evidence for animals currently unrecorded in the osteological record of the lEF.

Horseshoe crab trace fossils from the Upper Cretaceous Two Medicine Formation of Montana, USA, and a brief review of the xiphosurid ichnological record

AbstractA locality in the Upper Cretaceous Two Medicine Formation of Montana preserves abundant and variable horseshoe crab tracks and trails of the ichnotaxon Kouphichnium isp. These specimens span six morphologies differing in track form and trail configuration. These differences likely reflect variations in track-maker locomotion and behavior, substrate consistency, epichnial versus hypichnial preservation, and undertrack versus true tracks. Several tracks preserve the first clear appendage impressions for an extinct horseshoe crab. This discovery adds new information to the fossil horseshoe crab diversity in the Cretaceous Period. Trackway dimensions, such as the external width across the pusher legs or of the prosomal drag mark, provide information on the track-maker size. Most trackways correspond with crabs 9–14 cm wide; the abundance but limited size range of the traces suggests the large assemblage corresponds to a mating aggregation. The trace fossil record of xiphosurids indicates that throughout their history, horseshoe crabs inhabited both marine and nonmarine settings. They were definitively present in freshwater habitats from the lower Carboniferous through at least the Paleogene. Horseshoe crab trace abundance is highest from the upper Carboniferous through the Jurassic and likely reflects two factors: true upper Carboniferous taxonomic diversity and a preponderance of suitable sites for trackway preservation in the Late Triassic and Jurassic. Cretaceous traces are uncommon, and this Two Medicine locality is the first occurrence of horseshoe crab traces in the Late Cretaceous worldwide. Overall, track abundance and diversity would seem to correspond well with the reported horseshoe crab body fossil record.

SMALL FOOTPRINTS EXPAND MIDDLE PERMIAN AMPHIBIAN DIVERSITY IN THE SOUTH AFRICAN KAROO

ABSTRACTTwo new tetrapod trackways are described from the Tapinocephalus Assemblage Zone of the South African Karoo Basin. We interpret both to be traces attributable to small anamniote tetrapods. The larger footprints are tentatively referred to aff. Batrachichnus salamandroides. These imprints are distinguished from other records of Batrachichnus by a pentadactyl pes that produces only impressions of digits III–V. Digits I and II are recognized only by their drag marks. This trace occurs in association with a second set of footprints of uncertain affinities. However, these smaller imprints are not sufficiently well preserved and could represent undertracks or partially eroded footprints. None of the footprints can be attributed to the adult forms of the two temnospondyl taxa known from the Guadalupian part of the Karoo Basin: Rhinesuchus whaitsi or Rhinesuchoides tenuiceps. We interpret the aff. Batrachichnus trackway to have been produced by a small, adult temnospondyl or microsaur (Recumbirostrae), whereas the smaller set of footprints was likely made by a juvenile rhinesuchid or an unknown amphibian, either a paedomorphic form or a tiny adult form. The discovery shows that a more diverse aquatic biota existed at this time in the Karoo than osteological records currently suggest.

Lower Eocene Footprints from Northwest Washington, USA. Part 1: Reptile Tracks

Lower Eocene fluvial strata in the Chuckanut Formation preserve abundant bird and mammal tracks. Reptile trace fossils include footprints from a small turtle (ichnogenus Chelonipus), and several Crocodylian trackways that consist of irregularly spaced footprints associated with linear tail drag marks. The latter trackways represent “punting” locomotion, where a submerged Crocodylian used intermittent substrate contacts to provide forward motion of their neutrally buoyant bodies. Two adjacent sandstone blocks preserve Crocodylian trace fossils that are named herein as a new ichnogenus and ichnospecies Anticusuchipes amnis. Two other Crocodylian trackways lack sufficient detail for ichnotaxonomic assignment.

Experimental neoichnology of crawling stalked crinoids

Stalked crinoids have long been considered sessile. In the 1980s, however, observations both in the field and of laboratory experiments proved that some of them (isocrinids) can actively relocate by crawling with their arms on the substrate, and dragging the stalk behind them. Although it has been argued that this activity may leave traces on the sediment surface, no photographs or images of the traces produced by crawling crinoids have been available. Herein, we present results of neoichnological experiments using the shallowest species of living stalked crinoid, Metacrinus rotundus, dredged from Suruga Bay (near the town of Numazu, Shizuoka Prefecture, ~ 140 m depth). Our results demonstrate that isocrinids produce characteristic locomotion traces, which have some preservation potential. They are composed of rather deep and wide, sometimes weakly sinuous, central drag marks left by the stalk and cirri, and short, shallow scratch marks made by the arms. Based on the functional morphology and taphonomy, it has been argued that the ability to autotomize the stalk and relocate had already evolved in the oldest stem-group isocrinids (holocrinids), likely in response to increased benthic predation pressure during the so-called Mesozoic marine revolution. Our data show that this hypothesis may be corroborated in the future by ichnological findings, which may provide more direct proof of active locomotion in Triassic holocrinids.

Effect of Slag-Steel Reaction on the Initial Solidification of Molten Steel during Continuous Casting

With the mold simulator technique, the effect of slag-steel reaction on the initial shell solidification as well as the heat transfer and lubrication behavior of the infiltrated mold/shell slag film was studied in this article. The results showed that the Al2O3 content, the CaO/SiO2 ratio, and the viscosity of mold flux were increased with the progress of the slag-steel reaction during casting. The slag-steel reaction has two major effects on the initial shell solidification: one is increasing the mold heat flux and shell thickness by the decrease of slag film thickness. The other is the reduction of mold heat flux by the increase of crystal fraction in slag film. Mold flux with a lower basicity, viscosity, and crystallization temperature would result in a larger liquid slag consumption and the uneven infiltration of slag into the mold and shell gap that eventually leads to the irregular solidification of initial shell with a poor surface quality, such as slag entrapment and depressions as well as glaciation marks. Conversely, mold flux with a higher viscosity, basicity, and crystallization temperature would result in a smaller liquid slag consumption, which would cause the poor mold lubrication, the longitudinal shell surface defects, and drag marks.

A tetrapod swimming traceway from the Triassic of Winterswijk, the Netherlands

AbstractWe describe a tetrapod swimming traceway from the Middle Triassic Vossenveld Formation of the Netherlands. Forty-five individual traces, each consisting of two parallel claw drag marks, were followed over 9 m in a roughly east–west direction. The asymmetry of the traceway geometry indicates the trace maker negotiated a lateral current. The trace maker could not be identified, but the traces described here are markedly different fromDikoposichnustraces attributed to swimming nothosaurs.

An 8.5 m long ammonite drag mark from the Upper Jurassic Solnhofen Lithographic Limestones, Germany

Trackways and tracemakers preserved together in the fossil record are rare. However, the co-occurrence of a drag mark, together with the dead animal that produced it, is exceptional. Here, we describe an 8.5 m long ammonite drag mark complete with the preserved ammonite shell (Subplanites rueppellianus) at its end. Previously recorded examples preserve ammonites with drag marks of < 1 m. The specimen was recovered from a quarry near Solnhofen, southern Germany. The drag mark consists of continuous parallel ridges and furrows produced by the ribs of the ammonite shell as it drifted just above the sediment surface, and does not reflect behaviour of the living animal.

A taphonomic signature for quolls in the Australian archaeological record

Australian archaeofaunal assemblages are often heavily fragmented by taphonomic agents whose identity or origins are frequently difficult to discern. This study explores whether the fragmentation and accumulation of bone by carnivorous marsupial quolls may be distinguished from that produced by humans. Analyses of 140 scats obtained from captive feeding trials and wild populations of three quoll species (Dasyurus maculatus, Dasyurus viverrinus and Dasyurus hallucatus) indicates that damage to bones by quolls may be identified through a combination of the median length of bone specimens and observations of specific types of damage to the bone surface. Our results demonstrate that bone consumed by D. viverrinus and D. hallucatus is highly unlikely to be confused with human-accumulated assemblages due to low dietary overlap and the very small bone fragment size produced by both quoll species. Bone accumulations of the larger D. maculatus species, however, may be incorrectly attributed to humans due to the consumption of medium-large mammals by both humans and quolls, and the larger size of bone fragments produced by D. maculatus. Although fragments as large as 25mm were recovered from wild D. maculatus scats, the median length of scat-bone fragments for D. maculatus falls between ~8.30–10.40mm. This is significantly different statistically to the median fragment length (11.90mm) of bone in scats of the Tasmanian devil, Sarcophilus harrisii, as reported by Caroline Northwood (1990). Scats from wild D. maculatus indicate that polish and pitting are the most common forms of surface damage to bone, with more than 25% of specimens displaying these marks. Punctures and tooth drag marks are far rarer, with only 5% of bone specimens exhibiting this kind of damage. In light of these results, we advocate for detailed observation of the surface of bone specimens, along with obtaining specimen lengths, in order to distinguish quoll accumulated bone in archaeofaunal assemblages.

Crocodylian Tracks from Lower Oligocene Flysch deposits of the Barail Group, Manipur, India

A marine tidal delta siltstone from Gelmon locality in Northeast India preserved three crocodylian footprints and an elongate depression that appears to be a tail drag mark. Similar drag marks occur in nearby bedding surfaces. The discovery of crocodylian tracks from the basal part of Laisong Formation, Barail Group (Late Eocene–Early Oligocene age) of Manipur, India is noteworthy because of the age and the geographic location. Crocodylian tracks are rare in Cenozoic formations and they have not previously been reported from Asia. The footprints are herein named as a new ichnogenus and ichnospecies, Indosuchipes manipurensis.

A temnospondyl trackway from the early Mesozoic of western Gondwana and its implications for basal tetrapod locomotion.

BackgroundTemnospondyls are one of the earliest radiations of limbed vertebrates. Skeletal remains of more than 190 genera have been identified from late Paleozoic and early Mesozoic rocks. Paleozoic temnospondyls comprise mainly small to medium sized forms of diverse habits ranging from fully aquatic to fully terrestrial. Accordingly, their ichnological record includes tracks described from many Laurasian localities. Mesozoic temnospondyls, in contrast, include mostly medium to large aquatic or semi-aquatic forms. Exceedingly few fossil tracks or trackways have been attributed to Mesozoic temnospondyls, and as a consequence very little is known of their locomotor capabilities on land.Methodology/Principal FindingsWe report a ca. 200 Ma trackway, Episcopopus ventrosus, from Lesotho, southern Africa that was made by a 3.5 m-long animal. This relatively long trackway records the trackmaker dragging its body along a wet substrate using only the tips of its digits, which in the manus left characteristic drag marks. Based on detailed mapping, casting, and laser scanning of the best-preserved part of the trackway, we identified synapomorphies (e.g., tetradactyl manus, pentadactyl pes) and symplesiomorphies (e.g., absence of claws) in the Episcopopus trackway that indicate a temnospondyl trackmaker.Conclusions/SignificanceOur analysis shows that the Episcopopus trackmaker progressed with a sprawling posture, using a lateral-sequence walk. Its forelimbs were the major propulsive elements and there was little lateral bending of the trunk. We suggest this locomotor style, which differs dramatically from the hindlimb-driven locomotion of salamanders and other extant terrestrial tetrapods can be explained by the forwardly shifted center of mass resulting from the relatively large heads and heavily pectoral girdles of temnospondyls.

Crystallization Characteristics of CaO-Al2O3-Based Mold Flux and Their Effects on In-Mold Performance during High-Aluminum TRIP Steels Continuous Casting

Crystallization behaviors of the newly developed lime-alumina-based mold fluxes for high-aluminum transformation induced plasticity (TRIP) steels casting were experimentally studied, and compared with those of lime-silica-based mold fluxes. The effects of mold flux crystallization characteristics on heat transfer and lubrication performance in casting high-Al TRIP steels were also evaluated. The results show that the crystallization temperatures of lime-alumina-based mold fluxes are much lower than those of lime-silica-based mold fluxes. Increasing B2O3 addition suppresses the crystallization of lime-alumina-based mold fluxes, while Na2O exhibits an opposite effect. In continuous cooling of lime-alumina-based mold fluxes with high B2O3 contents and a CaO/Al2O3 ratio of 3.3, faceted cuspidine precipitates first, followed by needle-like CaO·B2O3 or 9CaO·3B2O3·CaF2. In lime-alumina-based mold flux with low B2O3 content (5.4 mass pct) and a CaO/Al2O3 ratio of 1.2, the formation of fine CaF2 takes place first, followed by blocky interconnected CaO·2Al2O3 as the dominant crystalline phase, and rod-like 2CaO·B2O3 precipitates at lower temperature during continuous cooling of the mold flux. In B2O3-free mold flux, blocky interconnected 3CaO·Al2O3 precipitates after CaF2 and 3CaO·2SiO2 formation, and takes up almost the whole crystalline fraction. The casting trials show that the mold heat transfer rate significantly decreases near the meniscus during the continuous casting using lime-alumina-mold fluxes with higher crystallinity, which brings a great reduction of surface depressions on cast slabs. However, excessive crystallinity of mold flux causes poor lubrication between mold and solidifying steel shell, which induces various defects such as drag marks on cast slab. Among the studied mold fluxes, lime-alumina-based mold fluxes with higher B2O3 contents and a CaO/Al2O3 ratio of 3.3 show comparatively improved performance.

Ichnology of an Extant Belly-Dragging Lizard—Analogies to Early Reptile Locomotion?

A recently described Erpetopus trackway bearing unusual claw and belly-drag marks ostensibly indicates an obligatory sprawled posture and belly-walk in the locomotion of small captorhinids. Here, the ichnology of the blue-tongued skink (Tiliqua scincoides) is investigated in order to identify features of a trackway produced by a lizard in continuous belly-walk. Comparisons between T. scincoides and Erpetopus tracks tested whether the locomotory pattern observed for T. scincoides resembles that of small captorhinid track makers. Characteristic features of the T. scincoides track include: (1) a belly-dragging mark, (2) claw scratch marks produced during the early stance phase, and (3) claw drag marks produced by the forelimb during the swing phase. Trackway parameters did not correlate with track maker velocity, rendering inference of velocity for belly-dragging track makers problematic. This result was probably caused by increased substrate influence on locomotor speed because of belly contact with the ground. The track characteristics of T. scincoides match those recently described for Erpetopus and thus corroborate the notion of a similar pattern of locomotion for small captorhinids.