Sauropod tracks from the Middle Jurassic Chuanjie Formation of Yunnan Province and the pre-Cretaceous sauropodomorph trackways from China

The Xixipo dinosaur tracksite in the Chuanjie Formation of Yunnan Province is one of the 14 Chinese sites yielding sauropod tracks from between the Triassic–Jurassic and Jurassic–Cretaceous boundaries, but is only one of the two that represent the Middle Jurassic. Although it is a small site, it adds incrementally to the overall track record of the region and allows comparison with the body fossil record and classification of the Chuanjie Formation as a Type 3b or Type 4b deposit in which both the body fossil and trace fossil record, in this case representing sauropodomorphs, are similar in composition and frequency of occurrence. We argue that the sauropod trace and body fossil records, while based on different categories of evidence, are very important. Integrating and correlating all available data from both records increases our understanding of sauropod communities, and both are equally valuable for this. In addition, we also discuss narrow to wide gauge, coeval sauropod trackways from China, and the relationship between the potential trackmaker of China's Jurassic Brontopodus-type trackways and mamenchisaurids and, beginning from the Late Jurassic, representatives of this type and titanosauriform sauropods.     

First Jurassic dinosaur tracksite from Guizhou Province,China: morphology,trackmaker and paleoecology

Abstract

Sauropod tracks from the Early Jurassic Maanshan Member of the Ziliujing Formation in the Dazhuanwan area of Guizhou represent the first Jurassic dinosaur track record for this province. The best preserved and longest trackway is narrow gauge (Brontopodus type), and indicates a relatively small trackmaker (footprint length ~35.0 cm). In conjunction with sauropodomorph skeletal remains these tracks suggest that basal sauropodomorphs and primitive sauropods coexisted in this region during the Early Jurassic. This pattern is same in the Lufeng and Sichuan basins. Thus, sauropod tracks from southwest China are diverse in the Early Jurassic, and include narrow gauge Parabrontopodus, wide gauge Brontopodus-type, and basal sauropodomorph tracks.     

Sauropod Trackway Reflecting an Unusual Walking Pattern from the Early Cretaceous of Shandong Province,China

The trackway of a quadrupedal dinosaur from the Early Cretaceous (Albian) Qingquan tracksite (Tancheng, Shandong Province) is redescribed, and the trackmaker is identified as a sauropod. The trackway makes a slight turn towards the northwest and is characterized by an extremely narrow gauge pattern and an unusual configuration, i.e., a conspicuous difference between the position of the left and right manus tracks with respect to the position of the preceding pes track. Left manus tracks are located on the inside of the trackway, very close (and sometimes even in connection) to the opposite right pes tracks. So far, the Qingquan trackway is possibly the only extremely narrow-gauge sauropod trackway known from China. However, it is not clear to what extent this extremely narrow gauge pattern is related to the turning or a special behavior, or even linked to an injury (“limping trackway”). We tentatively attribute the Qingquan trackway to cf. Parabrontopodus, even though it has a rather low heteropody that is significantly lower than in Parabrontopodus and not typical for narrow-gauge sauropod trackways, but occurs in the wide-gauge ichnotaxon Brontopodus. Because of this discrepancy, the Qingquan trackway cannot readily be attributed to a more basal sauropod, which is generally considered the producer of narrow-gauge trackways. Therefore, the identification of a distinct sauropod group is not possible presently. The only skeletal remains of sauropods from the Lower Cretaceous of Shandong Province belong to the large titanosauriform, Euhelopus zdanskyi.     

Preliminary Report on the Courtedoux Dinosaur Tracksite from the Kimmeridgian of Switzerland

In 2002 a new dinosaur tracksite was discovered in calcareous laminites of early Late Kimmeridgian age along the future course of the “Transjurane” highway in Courtedoux, Canton Jura, Northern Switzerland. The site has an extraordinary scientific potential, as the laminites, which have been deposited in an intertidal to supratidal environment, contain at least 6 track-bearing levels in a total thickness of about 1 m. The laminites are being systematically excavated by the “Section de paleontologie” over an area of approximately 1500 m². So far the main track level has been uncovered over an area of about 650 m², which reveals 2 trackways of theropods and 17 trackways of sauropods. The sauropod tracks are the smallest known in the Kimmeridgian so far, and the trackways belong to the ichnogenus Parabrontopodus, which has been revealed for the first time in Switzerland. The tracksite belongs to the “Middle Kimmeridgian megatracksite” sensu Meyer (2000), and represents the most important dinosaur tracksite in Switzerland, perhaps with the potential for development into one of the world's largest sauropod tracksites. It will be protected in situ underneath an especially constructed highway-bridge, thus offering opportunities for future research and the development of an interpretative center for education and tourism.     

A theropod–sauropod track assemblage from the ?Middle–Upper Jurassic Shedian Formation at Shuangbai,Yunnan Province,China, reflecting different sizes of trackmakers: Review and new observations

A dinosaur tracksite at Hemenkou (Shuangbai County, Yunnan Province) in the ?Middle–Upper Jurassic Shedian Formation that consists mainly of gray-purple feldspathic quartz sandstones was previously reported incorrectly as being in the Lower Cretaceous Puchanghe Formation. The previous assignment is also inconsistent with two regional geological maps. Although mostly yielding poorly preserved tracks, the site nevertheless indicates a diversity of theropod and sauropod trackmakers partly consistent with the Late Jurassic body fossils from the region. Purported ornithopod are re-evaluated here as those of theropods. The theropod tracks and trackways show distinct similarities to those of the Grallator–Eubrontes plexus and can be subdivided into three morphotypes that may reflect different pes anatomy and/or substrate conditions. Two sizes of tracks (small, large) indicate the presence of different size classes or species in this area in the Late Jurassic. Similarly, the sauropod trackways document three differently sized trackmakers (small–medium–large) showing a typical wide-gauge (Brontopodus) pattern. The track record is the first evidence of theropods in the ?Middle–Late Jurassic of central Yunnan, whereas the sauropod tracks suggest a relation to the coeval basal eusauropods known from this region by skeletal remains.     

Large sauropod and theropod tracks from the Middle Jurassic Chuanjie Formation of Lufeng County,Yunnan Province and palaeobiogeography of the Middle Jurassic sauropod tracks from southwestern China

Tracks of large theropods and a single sauropod footprint are reported from red beds at Beikeshan locality in the Middle Jurassic Chuanjie Formation, of Lufeng County, near the large World Dinosaur Valley Park complex. The Chuanjie theropod tracks are assigned to the ichnogenus Eubrontes and the large sauropod track is given the provisional label Brontopodus. All occur as isolated tracks, i.e., trackways are not preserved. Saurischian dominated ichnofaunas are relatively common in the Jurassic of China. The producers of the Chuanjie tracks may have been similar to the basal tetanuran theropod Shidaisaurus and to mamenchisaurid sauropods, which were widely distributed throughout China, during the Jurassic, and are known from skeletal remains found in the same unit. Other potential sauropod trackmakers include titanosauriforms or as-yet-unknown basal eusauropods. The ichno- and skeletal records from the Jurassic of the Lufeng Basin are largely consistent, and both document the presence of middle-large sized theropods and sauropods.     

Lavinipes Cheminii Ichnogen., Ichnosp. nov., A Possible Sauropodomorph Track from the Lower Jurassic of the Italian Alps

A new ichnotaxon is described from the Lower Jurassic (Upper Hettangian-Lower Sinemurian) carbonate tidal flats on the central-eastern Italian Alps. The narrow-gauge trackway is that of a large quadrupedal dinosaur. The pes is functionally tetradactyl with three rounded antero-medially directed digits, and the manus is pentadactyl. This quadrupedal form is close to Otozoum and Pseudotetrasauropus jaquesi both traditionally related to sauropodomorph trackmakers. The similarity with Otozoum is so marked that Lavinipes and Otozoum could be cogeneric. But the overall evidence today is that the Otozoum trackmaker was generally bipedal, whereas the trackmaker of L. cheminii is fully quadrupedal. The manual prints of L. cheminii show five short clawless digits and are different from the tetradactyl slender toed manual prints of Otozoum. The possible sauropodomorph affinity of the L. cheminii trackmaker is here discussed with an attempt to a revision of the Late Triassic-Jurassic tracks which have been traditionally related to sauropod and prosauropod.     

Les pistes d’archosauriens : Kayentapus ubacensis nov. isp. (théropodes) et crocodylomorphes du Bathonien des Grands-Causses (France). Conséquences paléo-biologiques,environnementales et géographiques

Two tracksites yielding tridactyl footprints II-IV of theropods as well as supposedly sauropod tracks from the Causses Basin, briefly described in 2006 are reinvestigated. They are the Capelan tracksite (Meyrueis, Lozère) and the Garène tracksite (La Roque-Sainte-Marguerite, Aveyron), both Bathonian in age. In 2012, one of them (Le Capelan) was excavated and enlarged, allowing the discovery of numerous new tracks. In the Capelan tracksite, 102 concave epireliefs, 11 to 36 cm long, represent at least 21 trackways; the longest being visible along 37 meters. Footprints are almost as long as wide and show a large divarication angle II-IV (up to 70°). The largest of them (more than 24 cm long) were statistically compared with different Middle and Upper Jurassic ichnotaxa for which a synthesis is proposed. Tracks from the Causses Basin as well as those from the Capelan and the Garène tracksites can be ascribed to the ichnogenus Kayentapus. We propose a new ichnospecies K. ubacensis nov. isp. Whose trackmakers were tetanurian theropods, probably megalosaurids. At the Capelan, some marks are tentatively interpreted as swim tracks of crocodylomorphs. The supposedly sauropod tracks are here reinterpreted and considered as erosion cups and as concavities indicating the location of tree trunks. The sedimentological analysis indicates a paralic environment including lagoons and freshwater to brackish bays. They were separated from dysoxic lagoons by calcarenitic coastal barrier spits, and by tidal flats where microbial mats contributed to the good preservation of trackways. Despite the presence of “mangroves”, the main track-bearing surface from the Capelan was quite open and visited by megalosaurid dinosaurs of various sizes, moving in all directions but preferably to the North. The regional palaeogeography of the early-middle Bathonian is in accordance with a coastal area with low relief, bordering the “Seuil Cévenol”, which was probably emerged.     

Maastrichtian Sauropod footprints from the Fumanya site,Berguedà, Spain

A sauropod tracksite near Fumanya (Berguedà, Catalunya, Spain) was mapped in detail in 1996. Discovered by Viladrich (1986), this is the only known Maastrichtian sauropod tracksite in Europe. The tracks have been strongly affected by strain and erosion. The wide‐gauged, four‐clawed pes trackways are attributed to titanosaurs. Although most trackways indicate single individuals, a few trackways involved multiple individuals, suggesting social behavior.     

Thunder lizard handstands: Manus-only sauropod trackways from the Glen Rose Formation (Lower Cretaceous,Kendall County,Texas)

Abstract

Three parallel, manus-only sauropod trackways from the Coffee Hollow A-Male tracksite (Glen Rose Formation, Kendall County, Texas) were studied separately by researchers from the Heritage Museum of the Texas Hill Country and the Houston Museum of Natural Sciences. Footprint and trackway measurements generally show good agreement between the two groups’ data sets. Footprints appear to be shallowly impressed true tracks rather than undertracks. One of the Coffee Hollow trackways shows marked asymmetry in the lengths of paces that begin with the left as opposed to the right forefoot, and two of the Coffee Hollow trackways are unusually broad. The Coffee Hollow trackways differ enough from the manus portions of other Glen Rose Formation sauropod trackways to suggest that they were made by a different kind of sauropod. Greater differential pressure exerted on the substrate by the forefeet than the hindfeet probably explains the Coffee Hollow trackways, like other manus-only sauropod trackways, but the possibility that they indicate unusual locomotion cannot at present be ruled out.     

Theropod and possible ornithopod track assemblages from the Jurassic–Cretaceous boundary Houcheng Formation,Shangyi, northern Hebei,China

Dinosaur track assemblages from the Houcheng Formation in the small continental Shangyi Basin of northern Hebei Province, China bridge a gap in the record of vertebrates from this unit and enrich our knowledge of ichnofaunas from the Jurassic–Cretaceous boundary. Their stratigraphic position between the Middle Jurassic Yan-Liao Biota and the Lower Cretaceous Jehol Biota gives them a special importance. New discoveries allow a re-assessment of theropod and possible ornithopod tracks that are present with several trackways. Seventy-three footprints were examined and documented. Despite their smaller size, the tridactyl mesaxonic theropod tracks show morphological similarities with the ichnogenus Therangospodus known from the Upper Jurassic deposits of North America, Europe, and Central Asia. The possible ornithopod tracks lack an associated manus imprint, suggesting a bipedal trackmaker. These possible ornithopod tracks from the Houcheng Formation provide evidence for the presence of small basal ornithopods or basal Cerapoda in the Upper Jurassic–Lower Cretaceous in this region. The depositional environment was the margin of an extensive shallow lake with fluctuating water levels under seasonally dry climate.     

Lower Cretaceous theropod tracks with the new ichnogenus and combination Lockleypus luanpingensis from the Dabeigou Formation of the Luanping Basin,Hebei Province,China

Theropod footprints from the Jingshang tracksite in the Lower Cretaceous Dabeigou Formation of the Luanping Basin, Hebei Province, China, are re-evaluated after new discoveries at this locality. They occur in a succession with sandstone, mudstone, and calcareous shale. The depositional environment was a shallow lake shore, comparable in age to the famous Jehol Biota. Based on the distinct morphology with peculiar features of the ratio of the outer digits, the footprints formerly assigned to Changpeipus carbonicus are now referred to the new ichnogenus and combination Lockleypus luanpingensis. The possible trackmaker was a relatively large ornithomimosaurian theropod thus far not known from the skeletal record of the Jehol Biota.     

A New Sauropod Dinosaur from the Middle Jurassic of the United Kingdom

A new record of a sauropodomorph dinosaur is here described from the Middle Jurassic (Aalenian) Saltwick Formation of Whitby (Yorkshire), UK. A single caudal vertebra represents an early sauropodomorph and signifies the earliest recognised eusauropod dinosaur from the United Kingdom. The absence of pleurocoels and a narrow, dorsoventrally deep, but craniocaudally short centrum, suggests a primitive sauropodomorph. Distinct spinopostzygopophyseal laminae rise from the lateral margins of the postzygapophyses and pass caudally along what remains of the neural spine, a character unique to a subgroup of sauropods that includes Barapasaurus, Omeisaurus and other neosauropods and eusauropods. The lack of phylogenetically robust characters in sauropod caudal vertebrae usually makes it difficult to establish affinities, but the absence of mild procoely excludes this specimen from both Diplodocoidea and Lithostrotia. The vertebra cannot be further distinguished from those of a wide range of basal sauropods, cetiosaurids and basal macronarians. However, this plesiomorphic vertebra still signifies the earliest stratigraphic occurrence for a British sauropod dinosaur.     

First Thyreophoran Type Tracks from the Middle Jurassic Chuanjie Formation of Yunnan Province,China

Two tridactyl footprints from the Chuanjie Formation (Middle Jurassic) of Yunnan Province, China are morphological characteristics of thyreophoran tracks. They show some similarities to Shenmuichnus, known from the Early Jurassic strata of both Shaanxi and Yunnan provinces, but are somewhat larger, thereby resembling the ichnogenus Stegopodus. Based on their general morphology and size being congruent with this ichnogenus, they are tentatively assigned here to cf. Stegopodus. This is the fourth report of large ornithischian (probably thyreophoran) tracks from the Lower-Middle Jurassic of China that indicates relatively large trackmakers that were likely to be taxonomically distinct from much smaller and gracile Anomoepus trackmakers, also of ornithischian affinity. The larger tracks indicate a hitherto unreported abundance, size range and diversity of track types attributed to this group. The parallel orientation of the two best preserved trackways may indicate gregariousness.     

Manus-only titanosaurid trackway from Fumanya (Maastrichtian, Pyrenees): further evidence for an underprint origin

The origin of manus-only and manus dominated sauropod trackways has been a matter of intense debate since two hyphothesis exist: (a) manus-only and manus-dominated trackways result from a 'swimming' sauropod, and (b) they result from a selective underprint phenomenon that only leaves the manus recorded. Several new sauropod trackways are reported in the Fumanya tracksite area (Maastrichtian), in SE Pyrenees, where both tracks and undertracks are found on the same stratigraphic bedding surface. In one of the trackways, footprint morphology together with the trackway pattern displays a clear succession of manus-only impressions attributed to a sauropod dinosaur in a walking gait. The ichnological comparison between the manus-only trackway with the other complete trackway (manus-pes) display an identical distribution of the manus pattern. This fact clearly points towards an underprint phenomenon as the origin for manus-only trackways, since it is rather unlikely that the same pattern would completely match different locomotion behaviours such as walking and swimming. Therefore, we suggest an interpretation based on the differential loading between the hindfoot and the forefoot on an upper stratigraphic track-level, for the studied manus-only trackway. □ Fumanya tracksite, manus-only trackways, titanosaurs, trackway pattern, underprint, Upper Cretaceous.     

A dinosaur ichnocoenosis from the middle jurassic of Yorkshire,UK

An assemblage of dinosaur tracks from the undersurface of a sandstone bed in the Saltwick Formation (Middle Jurassic) of Yorkshire shows a range of morphological types, preservational variants and behavioral styles. The tracks are combinations of transmitted prints and underprints and include three distinct trackways. One trackway was made by an animal walking on exposed damp sand, another was left by an animal swimming diagonally across a current and being swept down current, while the third may have been made by an animal either running or pushing off with its feet as it drifted down current. Environmental conditions that existed during the formation of the trackways varied between crevasse splay floods and exposed damp sand. The morphology of the swimming tracks is sufficiently distinctive to warrant the erection of a new ichnogenus and ichnospecies—Characichnos tridactylus. Previously described material from Kansas, Wyoming and New Mexico can be attributed to this new ichnogenus, while specimens from Germany and Utah are only provisionally referred to it. This indicates a known range from Triassic to Cretaceous.     

A Middle Jurassic dinosaur trackway site from Oxfordshire, UK

The Middle Jurassic (Bathonian) Ardley trackway site in Oxfordshire, UK is described in detail. The track site is extensive, containing over 40 more-or-less continuous theropod and sauropod trackways preserved together on a single bedding plane with some trackways up to 180 m in length. The trackways display reasonable preservation, with claw marks discernible. Sauropod trackways are by far the most abundant and are representative of taxa that exhibit both narrow and wide-gauge styles of locomotion. Theropod trackways are represented by large tridactyl prints and claw impressions that display exceptionally low pace angulation values during their walking phase. One theropod trackway is unique in that it reveals a gait transition associated with a temporary increase of speed. These dinosaurs were walking over a lime-mud firmground to hardground that was emergent, or locally very shallowly submerged. GPS (Global Positioning Satellite) data reveal that the tracks, preserved during a short time interval, trend in a north-easterly direction. Multi-herding behaviour is suggested for the sauropods of differing size. The discovery of this site adds significantly to our knowledge of the taxonomic composition of Middle Jurassic ecosystems. Evidence concerning locomotor styles employed by saurischian dinosaurs, footprint identification, potential trackmaker, social interactions and observations concerning estimates of Middle Jurassic faunal diversity, as well as aspects of dinosaur locomotor evolution are discussed.