Vertebrate Tracksites in the Middle Jurassic-Upper Cretaceous of South Tunisia

Four vertebrate tracksites from the Middle Jurassic and Upper Cretaceous in the Tataouine basin of southern Tunisia are described. Approximately 130 tridactyl footprints distributed over an area of 200 square meters, preserved on Callovian beds exposed at the Beni Ghedir site, represent the oldest evidence of a dinosaur fauna in Tunisia. In addition, three tracksites—Chenini, Ksar Ayaat, and Jebel Boulouha—have been discovered in the Cretaceous beds of the upper Continental Intercalaire, previously considered as a strictly marine depositional sequence. In addition to dinosaur tracks, the Chenini tracksite (late Albian) includes poorly preserved crocodilian tracks, and footprints assigned to a pleurodiran turtle have been recovered at the Ksar Ayaat locality (early Cenomanian). The Jebel Boulouha tracksite is dominated by well-preserved tridactyl tracks referred to small-sized theropods. Depositional settings of each tracksite have been defined on stratigraphic and sedimentologic data, and tracks were ascribed to different ichnocoenoses in relation to their paleoenvironments. This new and differentiated track record gives important information on how the fossil vertebrate fauna changed in southern Tunisia during mid-Jurassic to mid-Cretaceous times. These data provide a unique and useful census of tetrapod associations along the southern margin of the peri-Mediterranean area.     

Dinosaur Tracks,Myths and Buildings: The Jin Ji (Golden Chicken) Stones from Zizhou Area,Northern Shaanxi,China

For centuries, dinosaur footprints have influenced popular legends and myths in the surroundings of important tracksites. In many regions of China, track-bearing slabs were utilized as building materials and integrated in houses, yards, or cave dwellings, often serving as auspicious symbols or aesthetic decorations. Special birds such as the golden pheasant, widely distributed in China, may have inspired people to consider them as mythic trackmakers. The Zizhou area in northern Shaanxi, China, is famous for tracksites in the lower portion of the early Middle Jurassic Yan'an Formation. Sandstones with dinosaur tracks from these localities have been collected since the Ming Dynasty (1368–1644) and are used by villagers as cellar covers, stalls, or millstones. Besides their historical importance, the slabs are a valuable resource for ichnological research. Well-preserved theropod, ornithopod, and stegosaur tracks such as Kayentapus, Eubrontes, Anomoepus and Deltapodus incorporated into manmade structures can be seen while simply walking through some small villages of this area.     

Los Cayos Dinosaur Tracksite: An Overview on the Lower Cretaceous Ichno-Diversity of the Cameros Basin (Cornago,La Rioja Province,Spain)

The Los Cayos dinosaur tracksite is located at the eastern sector of the Cameros Basin (Cornago Township, La Rioja province), NE Spain. The sediments consist of interbedded terrigenous siliciclastics and carbonates belonging to the Enciso Group (Early Cretaceous, Aptian in age). The sedimentological and faunal evidence suggests that these sediments were deposited in a low gradient lacustrine environment. Los Cayos constitutes a relatively wide area with at least 6 localities that have yielded dinosaur tracks. More than 2,000 dinosaur tracks have been discovered to date. Medium to large theropod dinosaurs constitute about 95% of the ichnofauna. Ornithopod dinosaur tracks have been reported from only one of the outcrops (Los Cayos D). Los Cayos S has yielded theropod and sauropod tracks. One sauropod trackway shows a narrow-gauge locomotion pattern and a manus print morphology suggesting that the trackmaker was a titanosaurid, or at least a titanosauriform sauropod. Some pterosaur manus impressions, avian-like footprints of small size and possible turtle tracks complete the assemblage of one of the most impressive and best-preserved dinosaur tracksites of the European Lower Cretaceous.     

安徽省黄山地区恐龙(足迹)脚印化石的初步研究

简要报道了安徽省黄山地区所发现的恐龙足迹化石。从脚印的形态和足迹上看,至少有三种不同的恐龙（蜥脚类、兽脚类、鸟脚类）共同生存过,其中多数恐龙为两足行走性的。记述了两个典型的小型兽脚类和小型鸟脚类恐龙所留下的脚印化石。黄山地区恐龙足迹、骨骼化石及其蛋化石的发现,对于研究晚白垩世恐龙生活习性以及古气候环境均有着一定的意义。     

New dinosaur tracksites from the Middle Jurassic of Madagascar: ichnotaxonomical,behavioural and palaeoenvironmental implications

Abstract: New dinosaur tracksites are described from the Bajocian–Bathonian Bemaraha Formation of western Madagascar. Two track‐bearing surfaces can be followed over a distance of at least 4 km, suggesting the existence of a hitherto unrecognized megatracksite. The track assemblage is theropod dominated, but sauropod tracks also occur at one site. Qualitative and quantitative analysis of the abundant theropod track material suggests that most, if not all, theropod footprints are attributable to a single trackmaker and are referred to Kayentapus isp. Although this ichnogenus, originally described from the Lower Jurassic of North America, has never been recorded from Gondwana nor from the Middle Jurassic, track morphology strongly suggests this attribution. Palaeogeographical, sedimentological and ichnological data suggest that the dinosaur tracks formed in an intertidal to supratidal setting where the coastline influenced the preferred walking direction of the animals.     

Dinosaur Footprints from the Lower Cretaceous Sarten Member of the Mojado Formation at Cerro de Cristo Rey,Dona Ana County,New Mexico

Dinosaur tracks and swimming traces have been discovered at three localities in the latest Albian Sarten Member of the Mojado Formation, Bisbee Group (= “Anapra Sandstone”), at Cerro de Cristo Rey in Sunland Park, southernmost Dona Ana County, New Mexico. These localities preserve footprints of ornithopod (Caririchnium) and theropod (Magnoavipes) dinosaurs, ?reptilian swimming traces and possible tracks of an ankylosaurian dinosaur. The Sarten Member is of the latest Albian age, so the Cerro de Cristo Rey tracks are slightly younger than the well-known late Albian tracksites of northeastern New Mexico. At Cerro de Cristo Rey, the dominance of ornithopod tracks and absence of sauropod tracks fit regional patterns of late Albian-early Cenomanian track distribution consistent with North American extirpation of sauropods before the end of Albian time. The deltaic/coastal plain depositional setting of the Sarten Member is also remarkably similar to the track-bearing late Albian-Cenomanian sandstones of NE New Mexico, Oklahoma, Nebraska, and SE Colorado, which also have a tetrapod footprint ichnofacies dominated by ornithopod (Caririchnium) and theropod (Magnoavipes) tracks throughout the so-called “dinosaur freeway.”     

Two new dinosaur tracksites from the Lower Cretaceous Jiaguan Formation of Sichuan Basin,China: specific preservation and ichnotaxonomy

Two new dinosaur tracksites are reported from the Lower Cretaceous Jiaguan Formation in the Sichuan Basin, Qijiang District of Chongqing. These are the Gaoqing-Yongsheng and the Huibu tracksites, which represent the 13th and 14th reports from this formation. The Gaoqing-Yongsheng tracksite reveals the trackway of a large biped (ornithopod) in association with isolated sauropod tracks and large indeterminate undertracks with radial cracks. These features are preserved as natural casts with pebble infillings in a coarse, cross bedded and very thick bedded sandstone sequence. The Huibu tracksite reveals isolated theropod tracks and ornithopod tracks, the latter having a quadripartite, Caririchnium-like morphology, preserved in a thin bedded sandstone sequence with intercalated mudstone.     

New localities of Late Eocene vertebrate footprints from the Tarom Mountains,Northwestern Iran

We document Late Eocene vertebrate footprints from the Tarom Mountains of Iran that represent a significant addition to the record of proboscidean and perissodactyl footprints. These footprints are from sandstones and tuffaceous sandstones of strata equivalent to the Kond Formation that overlie middle Eocene sedimentary rocks and are overlain by Oligocene volcanics. The footprints are preserved at 16 tracksites from 10 distinct stratigraphic levels. The mammal footprints include the oldest known proboscidean tracks, assigned to Proboscipeda enigmatica Panin & Avram and to cf. Proboscipeda isp. Evident perissodactyl tracks are common, tridactyl footprints with distinct digit shapes and proportions assigned to the new ichnogenus and ichnospecies Moropopus elongatus. Footprints of small, hopping, rodent-like mammals are identified as Musaltipes taromi new ichnospecies. Other mammal footprints from the Tarom tracksites are indeterminate, and bird footprints are assigned to Avipeda isp. The Tarom tracksites document the oldest record of proboscidean footprints, and this indicates that proboscideans had reached the northern shore of Tethys by Late Eocene time. The abundance and distinctiveness of the Tarom perissodactyl tracks mirrors the abundance and diversity of moropomorph perissodactyls during the Middle-Late Eocene. The Tarom tracksites are the most extensive record of Eocene vertebrate footprints known from Iran.

http://zoobank.org/urn:lsid:zoobank.org:pub:F430F9DB-728F-4162-9791-DC2A5CC5ED43     

Deux nouveaux sites à traces de pas dinosauroïdes dans la Formation Dolomitique de l’Hettangien de Lozère,Languedoc-Roussillon,France

Recent ichnological studies revealed two new localities showing dinosaur footprints in the Hettangian Dolomitic Formation from the Causses Basin, southern France. The traces are reported from the northern part of the basin, in Lozère, an area where Lower Jurassic dinosaur ichnites were poorly documented. The surfaces bearing footprints are characterized by a large number of traces. The ichnites are ascribed to Grallator (Hitchcock, 1858), Dilophosauripus (Welles, 1971) and Eubrontes (Hitchcock, 1845) whose trackmakers were theropods. Although numerous tracksites were previously described in the southern part of the Causses Basin, these three ichnotaxa are for the first time observed in association into the Dolomitic Formation.     

Complex In-Substrate Dinosaur (Sauropoda,Ornithopoda) Foot Pathways Revealed by Deep Natural Track Casts from the Lower Cretaceous Xiagou and Zhonggou Formations,Gansu Province,China

Several new Early Cretaceous tracksites from the Lower Cretaceous Xiagou Formation of Gansu Province (China) with tracks of large sauropods and ornithopods are described. Previously reported bird tracks were missing due to human negligence. The studied specimens are preserved as impressions and shallow and deep natural track casts. These dinosaur tracks are first reported from the Jiuquan area in the Changma Basin, matching well with the skeletal record of diverse non-avian dinosaur-bird faunas of this region. Moreover, they add new data to the dinosaur ichnofaunas of the Lanzhou-Minhe Basin (Gansu Province) and indicate a wide distribution of dinosaur-bird assemblages in the Early Cretaceous. Regarding morphology, sauropod, and ornithopod tracks from the Lanzhou-Minhe Basin and the Jiuquan area are very similar to each other. Titanosauriform trackmakers are assumed for the sauropod tracks and possibly iguanodontids have left the large, tridactyl ornithopod tracks. Of particular interest are well-preserved, deep natural track casts of large ornithopods and sauropods preserving ridges and grooves as well as striation marks on the lateral sides of the casts that allow the reconstruction of complex pathways of the foot within the substrate. One particular sauropod pes–manus track cast even indicates lateral and vertical sliding within the sediment because of the presence of “double impressions of digits” on the bottom.     

An enigmatic early mesozoic dinosaur trackway from Zimbabwe

A trackway from Zimbabwe of probably the smallest dinosaur footprints recorded in Africa, is described and tentatively assigned to the Early Jurassic. The footprints are possibly those of a theropod and show strong negative (outward) rotation of the pes and are associated with manus prints. The shape of the footprints, unusual negative rotation, posterior curvature of digit IV and curious positioning of the manus prints in relation to the pes are enigmatic but somewhat reminiscent of Atreipus. Although a number of propositions are considered the most likely is that the animal was an immature dinosaur using a quadrupedal gait. A second trackway of slightly larger footprints of a bipedal theropod dinosaur is also recorded along with other diminutive tracks that suggest an early dinosaur assemblage, possibly dating from near the Trias‐sic‐Jurassic boundary.     

Asianopodus-type footprints from the Hekou Group of Honggu District,Lanzhou City,Gansu, China and the “heel” of large theropod tracks

An increasing number of dinosaur tracksites have been reported from the Cretaceous Hekou Group deposits of the Lanzhou-Minhe Basin in the Gansu Province region. These include small sites such as the Huazhuang tracksite, from the Honggu District reported here, the Zhongpu tracksite with multiple track levels but few well-preserved tracks, other small tracksites currently under investigation, and the large and diverse Liujixia National Dinosaur Geopark site at Yanguoxia, where intensive study is ongoing. Collectively these sites reveal that ichnofaunas in the Hekou Group are widespread and diverse. The Huazhuang tracksite yields a small assemblage of moderately well-preserved theropod tracks assigned to Asianopodus. This is the first report of Asianopodus from the Hekou Group. Huazhuang Asianopodus belongs to the Eubrontes morphotype. The large theropod tracks from Lanzhou-Minhe Basin were left by large theropod trackmakers with the same general foot morphology. The specimens are described in detail and compared with other theropod track morphotypes from the Lower Cretaceous of China and elsewhere. In general, although the metatarsophalangeal pads of some Jurassic Eubrontes-type tracks are aligned with the axis of digit III, this feature appears most common in the Early Cretaceous theropod (Eubrontes-type) tracks.     

Constructing and testing hypotheses of dinosaur foot motions from fossil tracks using digitization and simulation

Whilst bones present a static view of extinct animals, fossil footprints are a direct record of the activity and motion of the track maker. Deep footprints are a particularly good record of foot motion. Such footprints rarely look like the feet that made them; the sediment being heavily disturbed by the foot motion. Because of this, such tracks are often overlooked or dismissed in preference for more foot-like impressions. However, the deeper the foot penetrates the substrate, the more motion is captured in the sediment volume. We have used deep, penetrative, Jurassic dinosaur tracks which have been naturally split into layers, to reconstruct foot motions of animals living over 200 million years ago. We consider these reconstructions to be hypotheses of motion. To test these hypotheses, we use the Discrete Element Method, in which individual particles of substrate are simulated in response to a penetrating foot model. Simulations that produce virtual tracks morphologically similar to the fossils lend support to the motion being plausible, while simulations that result in very different final tracks serve to reject the hypothesis of motion and help generate a new hypothesis.     

Hints of the Early Jehol Biota: Important Dinosaur Footprint Assemblages from the Jurassic-Cretaceous Boundary Tuchengzi Formation in Beijing,China

New reports of dinosaur tracksites in the Tuchengzi Formation in the newly established Yanqing Global Geopark, Beijing, China, support previous inferences that the track assemblages from this formation are saurischian-dominated. More specifically, the assemblages appear theropod-dominated, with the majority of well-preserved tracks conforming to the Grallator type (sensus lato), thus representing relatively small trackmakers. Such ichnofaunas supplement the skeletal record from this unit that lacks theropods thus far, proving a larger diversity of dinosaur faunas in that region. Sauropods are represented by medium to large sized and narrow and wide-gauge groups, respectively. The latter correspond with earlier discoveries of titanosauriform skeletons in the same unit. Previous records of ornithischian tracks cannot be positively confirmed. Purported occurrences are re-evaluated here, the trackways and imprints, except of a single possible specimen, re-assigned to theropods. Palecologically the Tuchengzi ichnofauna is characteristic of semi-arid fluvio-lacustrine inland basins with Upper Jurassic-Lower Cretaceous deposits in northern China that all show assemblages with abundant theropod and sauropod tracks and minor components of ornithopod, pterosaur and bird tracks.     

Aptian dinosaur footprints from the Apulian platform (Bisceglie,Southern Italy) in the framework of periadriatic ichnosites

New dinosaur tracks have been found near Bisceglie (Bari, Apulia), on loose blocks ascribed to the Corato Member (late Bedoulian to early Gargasian) of the Calcare di Bari Fm. The material consists of isolated footprints as well as of short trackways of quadrupedal and bipedal dinosaurs. The new tracksite has yielded a quite differentiated dinosaur ichnocoenosis, including theropod, sauropod, thyreophoran and ornithopod footprints.The discovery of early Aptian dinosaur footprints in the limestone of the carbonate platform of southern Italy gives new insights on dinosaur distribution, and new palaeontological constraints for the palaeogeographic reconstruction of the Mediterranean Tethys during the Cretaceous. The analysis of this and others ichnosites of the periadriatic carbonate platforms, gives evidence of repeated emersions and of widespread land-vertebrates dwelling. The characteristics of the associations suggest that the trackmakers did not constitute a real coevolved association but the occasional co-occurrence of taxa after migration.The results emphasize the need of both structural and environmental continuity and walking ways between a southern continent and the periadriatic carbonate platforms during the Early Cretaceous.     

Diverse Dinosaur-Dominated Ichnofaunas from the Potomac Group (Lower Cretaceous) Maryland

Until recently fossil footprints were virtually unknown from the Cretaceous of the eastern United States. The discovery of about 300 footprints in iron-rich siliciclastic facies of the Patuxent Formation (Potomac Group) of Aptian age is undoubtedly one of the most significant Early Cretaceous track discoveries since the Paluxy track discoveries in Texas in the 1930s. The Patuxent tracks include theropod, sauropod, ankylosaur and ornithopod dinosaur footprints, pterosaur tracks, and miscellaneous mammal and other vertebrate ichnites that collectively suggest a diversity of about 14 morphotypes. This is about twice the previous maximum estimate for any known Early Cretaceous vertebrate ichnofauna. Among the more distinctive forms are excellent examples of hypsilophodontid tracks and a surprisingly large mammal footprint. A remarkable feature of the Patuxent track assemblage is the high proportion of small tracks indicative of hatchlings, independently verified by the discovery of a hatchling-sized dinosaur. Such evidence suggests the proximity of nest sites. The preservation of such small tracks is very rare in the Cretaceous track record, and indeed throughout most of the Mesozoic.

This unusual preservation not only provides us with a window into a diverse Early Cretaceous ecosystem, but it also suggests the potential of such facies to provide ichnological bonanzas. A remarkable feature of the assemblage is that it consists largely of reworked nodules and clasts that may have previously been reworked within the Patuxent Formation. Such unusual contexts of preservation should provide intriguing research opportunities for sedimentologists interested in the diagenesis and taphonomy of a unique track-bearing facies.     

Were some dinosaurs gregarious?

A careful survey of the dinosaur footprints and trackways (identified as Eubrontes, Anchisauripus and Grallator) at the Mt. Tom site north of Holyoke, Massachusetts, and plots of their orientations reveal that an improbable percentage (70%) of the tracks are oriented in a nearparallel course. All but one of these coincident ancient traverses were probably made by the same kind of Triassic dinosaur (the footprints of which are referred to as Eubrontes). Comparable trackway orientation patterns have been reported by Albritton (1942) near Comanche, Texas for an Early Cretaceous dinosaur (iguanodobntid?) and Bird (1941, 1944) cited paralled sauporod trackways of Early Cretaceous age near the Paluxy River in Texas. Probability dictates that these sub-parallel traverses were not independent events and the presence of other deviating trackways at all three sites indicates that the trackmakers probably were not confined in their passage by physical barriers. Furthermore, the coincidental occurrence of such natural barriers at all of the sites mentioned here seems highly improbable. the combinedevidence of the Massachusetts site and the two Texas localities, together with the apparently widespread occurrence of dinosaur trackway lineation, strongly indicates gregarious habits for several different kinds of dinosaurs.     

Dinosaur Tracks from the Kilmaluag Formation (Bathonian,Middle Jurassic) of Score Bay,Isle of Skye,Scotland, UK

Tracks of a juvenile theropod dinosaur with footprint lengths of between 2 and 9 cm as well as adults of the same ichnospecies with footprints of about 15–25 cm in length were found in the Bathonian (Middle Jurassic) Kilmaluag Formation of Score Bay, northwestern Trotternish Peninsula, Isle of Skye, Scotland, UK. Two footprint sizes occur together on the same bedding plane in the central portion of Score Bay, both in situ and on loose blocks. Another horizon containing footprints above this was also identified. The footprints from the lowest horizon were produced in a desiccated silty mud that was covered with sand. A close association of both adults and juveniles with similar travel direction indicated by the footprints may suggest post-hatching care in theropod dinosaurs. Other footprints, produced on a rippled sandy substrate, have been found on the slightly higher bedding plane at this locality. Loose blocks found 130 m to the northeast in the central part of Score Bay have not been correlated with any in situ sediments, but were preserved in a similar manner to those from the higher bedding plane. These tracks represent the youngest dinosaur remains yet found in Scotland.     

Tetradactyl footprints of an unknown affinity theropod dinosaur from the Upper Jurassic of Morocco

Background

New tetradactyl theropod footprints from Upper Jurassic (Oxfordian-Kimmeridgian) have been found in the Iouaridène syncline (Morocco). The tracksites are at several layers in the intermediate lacustrine unit of Iouaridène Formation. The footprints were named informally in previous works “Eutynichnium atlasipodus”. We consider as nomen nudum.

Methodology/Principal Findings

Boutakioutichnium atlasicus ichnogen. et ichnosp. nov. is mainly characterized by the hallux impression. It is long, strong, directed medially or forward, with two digital pads and with the proximal part of the first pad in lateral position. More than 100 footprints in 15 trackways have been studied with these features. The footprints are large, 38–48 cm in length, and 26–31 cm in width.

Conclusions/Significance

Boutakioutichnium mainly differs from other ichnotaxa with hallux impression in lacking metatarsal marks and in not being a very deep footprint. The distinct morphology of the hallux of the Boutakioutichnium trackmaker –i.e. size and hallux position- are unique in the dinosaur autopodial record to date.