Article

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

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Abstract

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.

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... The different values resulting from these two methods are juxtaposed, but the differences are left undiscussed. The body length: hip height ratio of 3.7:1, was used to roughly estimate the body length of the sauropod track makers (see Xing et al. 2014a for explanation of this method). ...
... Basal eusauropods include Nebulasaurus (Xing et al. 2013b). Brontopodus (Xing et al. 2014a(Xing et al. , p. 2021d) is a fairly common sauropod track from Middle Jurassic deposits in China, but is not well-preserved. Theropods. ...
... -Theropods from the Early Jurassic in Yunnan Province are diversely represented and include the neotheropods Sinosaurus (Young 1948;Xing 2012) There is only one known genus and species of theropod from the Middle Jurassic: Shidaisaurus (Wu et al. 2009). The possible corresponding tracks are Eubrontes, which are common throughout Jurassic deposits of China (Xing et al. 2014a). ...
Article
We report five new dinosaur track sites in Chaya County, about 120 km southeast of Changdu City. The track assemblages are dominated by sauropods (45 tracks), which have been identified tentatively as cf. Brontopodus. Also present are two thyreophoran trackways consisting of 13 tracks that show strong similarities with the ichnogenus Deltapodus, the potential trackmakers of which were probably stegosaurids. The sauropod tracks from the Chaya region are dominated by large tracks with different affinities if compared to those of the Changdu area. The isolated sauropod tracks from Changdu and Chaya regions show similar morphological patterns, but those from the Chaya region lack large scale tracks. This paper compares and discusses the known ichno and body fossil records of sauropods, theropods, and ornithischians from the Middle Jurassic of Yunnan, Sichuan, and eastern Tibet and their importance for our understanding of dinosaur faunas from this region. The absence of basal neornithischian records in the Yunnan and Changdu regions is likely a preservational bias but also an ecological pecularity cannot be completely excluded. The palaeogeographic position of the four sampled skeleton and track sites suggests the possible existence of a corridor through which faunal exchanges were taking place throughout the Jurassic.
... Skeletal records include the large sauropod Chuanjiesaurus (Fang et al., 2000;Sekiya, 2011) and the theropod Shidaisaurus (Wu et al., 2009). Track records include theropod tracks Eubrontes, the large sauropod track Brontopodus (Xing et al., 2014a), and thyreophoran tracks cf. Stegopodus (Xing et al., 2019a). ...
... Stegopodus (Xing et al., 2019a). However, the Brontopodus track recorded by Xing et al. (2014a) is an isolated and poorly preserved pes track. In 2019, Tao Wang from the Lufeng Land and Resources Bureau discovered a group of large sauropod tracks at the Xixipo tracksite (GPS: 24˚58 0 30.62 00 N, 102˚2 0 25.55 00 E) ( Fig. 1) in Lufeng County. ...
... There are 14 Jurassic sauropodomorph track sites in China: six Lower Jurassic sites (Xing et al., 2014c(Xing et al., , 2016d(Xing et al., , 2016e, 2016f, 2019b(Xing et al., , 2019c, two Middle Jurassic sites (Xing et al., 2014a and this paper), three Upper Jurassic sites (Xing et al., 2016g, in press), and one JurassicÀCretaceous boundary site (Xing et al., 2015a) (Table 2). These are presently attributed to three ichnogenera: ...
Article
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.
... Hip heights and speed estimations of the theropod and sauropods trackmakers were derived from the trackways following the methods of Alexander (1976) and Thulborn (1990). The average hip height to body length ratio is 1:2.63 for the theropod (Xing et al., 2009), and 1: 3.7 for sauropods (Xing et al., 2014a). Lockley (1991) and Lockley et al. (1994c) discussed the categorization of formations and facies according to the relative abundance (proportions) of trace (tracks) and body fossils. ...
... By these calculations, both trackmakers seem to have been walking. After the methods of Xing et al. (2014a), the track maker of YG-S1 and S2 has a body length of approximately 13.7e20.1 m and 9.9e14.6 m, respectively. ...
Article
A dinosaur track assemblage from a remote, high altitude (∼4,500–5,000 m) site on the is the first to be reported from this area. The location, here named the Yangguang tracksite, represents the Lower Cretaceous part of the Kezilesu Group consisting of feldspathic sandstones and dated as Hauterivian–Barremian on the basis of the palynoflora. As the site is a dangerous working environment, with a steep (65°) track-bearing surface and constant freeze-thaw-induced rock fall, a photographic survey was undertaken to obtain essential information, while the surface was exposed. The ichnofauna is saurischian-dominated consisting of more than 120 recognizable tracks comprising at least two diagnostic sauropod trackway segments (>90 tracks) and seven theropod trackways (>30 tracks). The sauropod trackways represent large animals (mean pes length ∼92 cm) and resemble Brontopodus, although somewhat more narrow-gauge than typical. The theropod trackways also represent large animals (mean track lengths > 40 cm) and resemble Iberosauripus from the Kimmeridgian–Berriasian of Spain which is characterized by a relatively short wide footy with weak mesaxony.
... Assuming a hip height/foot length ratio in the range of 4.0∶1-5.9∶1 for a sauropod [18][19] , the hip height of the [20] . The body length of the Tongbao sauropod trackmaker is esti• mated to be 4.5-9.1m. ...
... The Tongbao Brontopodus trackmaker has an ob• vious potential affinity with Tonganosaurus (Mamen• chisaurid) given their proximities. Brontopodus type tracks also exist in levels which yield Middle JurassicChuanjiesaurus (Mamenchisaurid)[20] . If Brontopodus tracks from the Chuanjie Formation correspond to Ch• uanjiesaurus, then Brontopodus may have affinity with ...
Article
Full-text available
Dinosaur track and bone records often occur at different locations. However, a few formations show a close correspondence between bones and tracks that correspond to likely trackmakers. In this paper, the authors report sauropod tracks (Brontopodus) in very close geographic and stratigraphic proximity to the type locality of the eusauropod Tonganosaurus hei in the middle-upper parts of the Lower Jurassic Yimen Formation in Tongbao Village, Huili County, Panxi region of Sichuan Province. This Huili tracktrackmaker correlation is possibly existent, but still needs more evidence to confirm. As the first Jurassic sauropod tracks found in the Panxi region, the Tongbao Brontopodus tracks have provided evidence indicating coexistence of primitive sauropod and basal sauropodomorphs in Southwest China during Early Jurassic.
... Large theropod tracks were also found in the Lower–Middle Jurassic of the Lufeng Basin: Eubrontes isp. from the Middle Jurassic of the Beikeshan tracksite (Xing et al., 2014b) and Eubrontes pareschequier from the Lower Jurassic of the Lufeng Basin (Xing et al., 2009a; Lockley et al., 2013). Based on the present characteristics, HMK-T3 tracks can be referred tentatively to cf. ...
... Additionally, some tracks were yielded from the Lower Jurassic, such as the Dazu (Lockley and Matsukawa, 2009) and the Zigong tracksites (Xing et al., 2014e). An isolated sauropod pes trace was also discovered from the Middle Jurassic at the Beikeshan tracksite, Yunnan (Xing et al., 2014b). Rare skeletons of basal eusauropods ( " mamenchisaurids " ) have been discovered in the Jurassic of central Yunnan (Fang et al., 2004). ...
Article
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.
... Sauropodomorph (Lufengosaurus) skeletal fossils were discovered in both the upper and the lower units of the Dalishu tracks layer. Sauropod and theropod bones have also been found in the Middle Jurassic Chuanjie Formation (Xing et al. 2014) (Figure 2). The lower part of the Lufeng Formation includes shallow lacustrine strata. ...
... This suggests that the Jurassic ornithischians from the Ordos Basin inhabited humid coal-bearing, fluviodeltaic facies (Li et al. 2012). In the Jurassic sediments of the Ordos Basin, the Early Jurassic Shenmuichnus youngteilhardorum and the Early -Middle Jurassic Anomoepus and Deltapodus tracks (Xing et al. 2014) are the only known evidences of ornithischians in this region. argued for a distinction between humid, clastic, coastal plain, coal-bearing facies dominated by ornithopods and ankylosaurs and semi-arid carbonate facies dominated by sauropods (McCrea et al. 2001). ...
Article
Full-text available
The new ichnospecies, Shenmuichnus wangi ichnosp. nov., is the first evidence for the presence of large ornithischians in the Early Jurassic of Yunnan Province, whereas the known skeletal record documents small species only. Until now Shenmuichnus was known from a single locality in Shaanxi Province by the ichnospecies Shenmuichnus youngteilhardorum. Compared with the latter, Shenmuichnus wangi is larger and shows a different trackway configuration, particularly in the relative position of manus and pes imprints. Palecologically, the occurrence of Shenmuichnus wangi in a red bed facies indicates the preference of distinctive environments of trackmakers of both ichnospecies, questioning former hypotheses of exclusivity of ornithischians in more humid climates. By abundance both skeletons and footprints of ornithischians suggest their role as a minor component in Early Jurassic saurischian dominated dinosaur faunas in this region.
... This characteristic is common in Eubrontes tracks, including type Eubrontes AC 151 (Olsen et al. 1998), and also distinguishes Eubrontes from Chongqingpus, a medium-large theropod track with a hallux impression (Xing et al. 2013a, b). This feature (MTP II) also distinguishes type Eubrontes and E. nobatai from most other Eubrontes, from common ichnogenus (Xing et al. 2009a(Xing et al. , 2014b; (i) Eubrontes zigongensis (Xing et al. 2014c); (j) Eubrontes platypus (Hitchcock 1858) Xiyang specimen (Yang and Yang 1987); (k) Eubrontes monax (Zhen et al. 1986;Lockley et al. 2013); (l) Eubrontes xiyangensis (Zhen et al. 1986;Lockley et al. 2013); (m) Changpeipus carbonicus (Xing et al. 2014b); (n) Eubrontes nianpanshanensis (Xing et al. 2016b); (o) Lufengopus dongi (Lü et al. 2006;Xing et al. 2014d); (p) Eubrontes (?) glenrosensis Hailiutu specimen (Li et al. 2010;Xing et al. 2021); (q) Lockleypus luanpingeris (Xing et al. 2018e); (r) Chapus lockleyi ); (s) Asianopodus pulvinicalyx (Matsukawa et al. 2005); (t) Asianopodus robustus (Li et al. 2011;Lockley et al. 2018); (u) Eubrontes nobitai (This study); (v) Eubrontes HX-T3 (Xing et al. 2015b); (w) Eubrontes BJA-T4 (Xing et al. 2016c) Kayentapus of the Early-Middle Jurassic (Lockley et al. 2011;Xing et al. 2020), and from such Cretaceous ichnogenera as Asianopodus (Fig. 6). ...
... Less well known are dinosaur fossils occurring in the Middle Jurassic Chuanjie and Zhanghe Formations. From the Chuanjie Formation, sauropod (Chuanjiesaurus, Sekiya 2011) and theropod (Shidaisaurus, Wu et al. 2009) body fossils are known as well as comparatively scarce and isolated trace fossils in the form of sauropod, theropod and thyreophoran tracks (Xing et al. 2014a(Xing et al. , 2019(Xing et al. , 2021b. From the Zhanghe Formation, these include eusauropod body fossils (Nebulasaurus, Xing et al. 2015;Eomamenchisaurus, Lü et al. 2008). ...
Article
Recently, dinosaur tracks were discovered in the vicinity of Zhemujiu village in Yimen County, Yunnan Province, representing the first dinosaur footprints found in the purplish-red sandy mudstone of Lower Jurassic Zhanghe Formation. This marks a significant discovery as evidence of dinosaurs from this formation has previously only been reported from body fossils. Nearly 100 tracks were observed at the site and two morphotypes were identified: Characichnos-like morphotype A, and Wintonopus-like morphotype B. Some dinosaurs scraped the substrate with the distal portions of their digits (morphotype A), while others punted by pushing either the digital plantar surface against the sediment or plunging their digits vertically into the sediment (morphotype B). These track morphotypes suggest small-bodied dinosaurs swam (fully buoyant) and punted (partially buoyant) aqueous palaeo-environments (respectively). The orientation of these Zhemujiu tracks indicates that some dinosaurs were moving along the same axis as the flow of the water while others were moving perpendicular to it, yet despite the high abundance and shared orientations of tracks, we find no evidence of gregarious behaviour. This Zhemujiu tracksite discovery expands our understanding of dinosaur swimming behaviour in the Mesozoic era, as well as the occurrence of these track morphologies in China.
... The different values resulting from these two methods are juxtaposed, but the differences are left undiscussed. The body length: hip height ratio of 3.7:1, was used to roughly estimate the body length of the sauropod track makers (Xing et al. 2014). ...
Article
A newly discovered dinosaur tracksite in the Middle Jurassic Xietan Formation of the Zigui Basin, is the first reported from Hubei Province, China. Access to the site is difficult due to the steep inclination (~60°) of the track-bearing beds. The tracks are poorly preserved and occur in a fragmented mudstone substrate. However, it is possible to identify a sauropod trackway and isolated tridactyl (theropod) tracks, suggesting a saurischian dominated ichnofauna. The preserved sauropod trackway falls into the range of a typical wide gauge sequence and, together with the overall shape of the imprints and low heteropody, points to the ichnogenus Brontopodus. The tracks are of relatively small size and can possibly be attributed to juveniles of a large species or, alternatively, to adults of a small species of eusauropods. The tridactyl tracks are incomplete and cannot be assigned to a distinct ichnotaxon with certainty.
... The different values resulting from these two methods are juxtaposed, but the differences are left undiscussed. The body length: hip height ratio of 3.7:1, was used to roughly estimate the body length of the sauropod track makers (Xing et al. 2014). ...
Article
A newly discovered dinosaur tracksite in the Middle Jurassic Xietan Formation of the Zigui Basin, is the first reported from Hubei Province, China. Access to the site is difficult due to the steep inclination (~60°) of the track-bearing beds. The tracks are poorly preserved and occur in a fragmented mudstone substrate. However, it is possible to identify a sauropod trackway and isolated tridactyl (theropod) tracks, suggesting a saurischian dominated ichnofauna. The preserved sauropod trackway falls into the range of a typical wide gauge sequence and, together with the overall shape of the imprints and low heteropody, points to the ichnogenus Brontopodus. The tracks are of relatively small size and can possibly be attributed to juveniles of a large species or, alternatively, to adults of a small species of eusauropods. The tridactyl tracks are incomplete and cannot be assigned to a distinct ichnotaxon with certainty.
... In Yunnan Province, a number of footprints are known from Lower to Upper Jurassic layers. Non-avian theropod tracks of all sizes are unambiguously predominant (Lockley et al., 2013), but some avian theropod, ornithopod, sauropod and thyreophoran tracks have been reported as well (Xing et al., 2014b;Xing et al., 2016b;Xing, Lockley & Romilio, 2019;. The theropod track record in the Jurassic of Yunnan includes 5 ichnogenera: Changpeipus (Young, 1960), Eubrontes (Hitchcock, 1845), Grallator (Hitchcock, 1858), Kayentapus (Welles, 1971), and Zhengichnus (Zhen et al., 1986). ...
Article
Full-text available
Yunnan Province is famous for its diversified Lufeng vertebrate faunas containing many saurischian dinosaur remains. In addition to the body fossil record, dinosaur ichnofossils have also been discovered in Yunnan, and the number of published track sites is on the rise. We report a theropod assemblage from the Lower Jurassic Fengjiahe Formation in Xiyang, central Yunnan. It is the third report and description of dinosaur footprints from the Fengjiahe Formation, and this new track site is the largest in number of footprints for theropods in Yunnan. Over one hundred footprints are preserved on different layers of a claystone-dominated succession close to the Lower-Middle Jurassic boundary. The track area is referred to as a lacustrine shallow-water paleoenvironment. Tracks vary in size, morphology, and preservation. All are tridactyl and digitigrade, and some are identified as undertracks. The best preserved footprints were divided into three morphotypes: morphotype A (>8 cm–27 cm–
... The smallest track at Lishi site is LS-S2, with a pes print length of 31.2 cm. As Xing et al (2014b) proposed, the body length/hip height ratio of sauropods is approximately 3.7:1, thus the body length of the LS-S2 trackmaker is about 5.3-6.8 m. The body length of the largest isolated track, LS-SI1, is about 11.4-14.6 ...
Article
The Jurassic-Cretaceous Tuchengzi Formation has yielded at least 16 known theropod-dominated tracksites from northeast China, and in this paper, a new locality, the Lishi site in Hebei Province, is documented. A tuff layer positioned stratigraphically 90 m below the trackway layer yielded a UPb date of 142.2 ± 0.9 Ma, placing the site in the Berriasian stage. The site includes sauropod tracks, assigned to Brontopodus, and large theropod tracks, informally assigned to Therangospodus and Megalosauripus as well as a well-preserved morphotype here named as Asianopodus wangi ichnosp. Nov. The Tuchengzi Formation theropod track assemblages have implications for theropod ontogeny, paleocommunity structure, palaeobiology and preferred habitats of different size groups, based on comparison with data from the skeletal record. The size-frequency distribution indicates that small theropod tracks (Footprint length, FL < 25 cm) represent the dominant trackmakers with estimated body masses of <100 kg, whereas intermediate sized trackmakers (FL 25.0 – ~38.0 cm) are comparatively scarce and there are no tracks suggestive of megatheropods with body masses of >1000 kg. The latter phenomenon is in contrast to recently published analyses from Cretaceous theropod skeletal data that recognize a gap between small and very large megatheropod individuals.
... This characteristic is common in Eubrontes tracks, including type Eubrontes AC 151 (Olsen et al. 1998), and also distinguishes Eubrontes from Chongqingpus, a medium-large theropod track with a hallux impression (Xing et al. 2013a, b). This feature (MTP II) also distinguishes type Eubrontes and E. nobatai from most other Eubrontes, from common ichnogenus (Xing et al. 2009a(Xing et al. , 2014b; (i) Eubrontes zigongensis (Xing et al. 2014c); (j) Eubrontes platypus (Hitchcock 1858) Xiyang specimen (Yang and Yang 1987); (k) Eubrontes monax (Zhen et al. 1986;Lockley et al. 2013); (l) Eubrontes xiyangensis (Zhen et al. 1986;Lockley et al. 2013); (m) Changpeipus carbonicus (Xing et al. 2014b); (n) Eubrontes nianpanshanensis (Xing et al. 2016b); (o) Lufengopus dongi (Lü et al. 2006;Xing et al. 2014d); (p) Eubrontes (?) glenrosensis Hailiutu specimen (Li et al. 2010;Xing et al. 2021); (q) Lockleypus luanpingeris (Xing et al. 2018e); (r) Chapus lockleyi ); (s) Asianopodus pulvinicalyx (Matsukawa et al. 2005); (t) Asianopodus robustus (Li et al. 2011;Lockley et al. 2018); (u) Eubrontes nobitai (This study); (v) Eubrontes HX-T3 (Xing et al. 2015b); (w) Eubrontes BJA-T4 (Xing et al. 2016c) Kayentapus of the Early-Middle Jurassic (Lockley et al. 2011;Xing et al. 2020), and from such Cretaceous ichnogenera as Asianopodus (Fig. 6). ...
Article
Full-text available
The Jiaguan Formation and the underlying Feitianshan Formation (Lower Cretaceous) in Sichuan Province yield multiple saurischian (theropod–sauropod) dominated ichnofaunas. To date, a moderate diversity of six theropod ichnogenera has been reported, but none of these have been identified at the ichnospecies level. Thus, many morphotypes have common “generic” labels such as Grallator , Eubrontes, cf. Eubrontes or even “ Eubrontes - Megalosauripus ” morphotype. These morphotypes are generally more typical of the Jurassic, whereas other more distinctive theropod tracks ( Minisauripus and Velociraptorichnus ) are restricted to the Cretaceous. The new ichnospecies Eubrontes nobitai ichnosp nov. is distinguished from Jurassic morphotypes based on a very well-preserved trackway and represents the first-named Eubrontes ichnospecies from the Cretaceous of Asia.
... Recent re-examination of the material led to the creation of a new mamenchisaurid taxon named Analong (Ren et al., 2020) ( Fig. 2; Table 1). The Chuanjie Fm. has also produced sauropod tracks attributed to mamenchisaurids (Xing et al., 2014). ...
Article
An incomplete dinosaur skeleton, including a partial skull, recently discovered from the Lower Jurassic Lufeng Formation of Yunnan, China, is here described. Except for its small size, little anatomical evidence supports, a priori, the non‐adult status of this new sauropodomorph specimen. Thus, osteohistological analyses were conducted, which suggest that the new specimen is a fast‐growing juvenile. Despite the abundant early sauropodomorph fossils collected from the Lufeng Formation, it represents only the second occurrence of a juvenile non‐sauropodan sauropodomorph in the Lufeng Basin. The anatomy of the specimen does not match that of other Lower Jurassic immature specimens. Although cranial material is preserved, it does not display diagnostic characters of the early sauropodomorphs from the same horizon, namely Lufengosaurus, Yizhousaurus and Yunnanosaurus. Our phylogenetic analysis, which places the new specimen in a position relatively distant to other Chinese sauropodomorphs, corroborates the systematic hypothesis indicated by the anatomical evidence that it is not referable to a species already excavated in Yunnan. However, this result should be interpreted with caution considering that ontogeny affects phylogenetic reconstruction. A thorough comparison with adult forms, taking into account ontogeny‐related characters, suggests that this new juvenile specimen could represent an unknown species of early sauropodomorph.
... The different values resulting from these two methods are juxtaposed, but the differences are left undiscussed. The body length: hip height ratio of 3.7:1, was used to roughly estimate the body length of the sauropod track makers (Xing et al. 2014). ...
Article
Multiple sauropod-track-bearing horizons occur in the Middle Jurassic Shaqiaomu Formation, in the Chaya Group of Eastern Tibet. These add to the report of a previously described sauropod trackway, which is a famous tourist attraction and became part of a folkloric legend. From an ichnological point of view, multiple track-bearing levels are consistent with the previous report of sauropod tracks, but allow for recognition of nine other levels with a cumulative total of ~88 tracks from which eight recognisable trackways have been identified. These range in size (pes length) from 22.0 to 99.3 cm, with the larger ones all associated with the appropriately named Dajiaoyin (meaning ‘large footprints’) site. The presence of sauropod tracks in the finer grained argillaceous, lower energy deposits, is characteristic for terrestrial facies environments favoured by sauropods. The track-bearing layers belong to continental shelf sequences that form part of the Lower-Middle Jurassic forearc basin deposits in the southern Qiangtang subterrane.
... Compared with Early and Late Jurassic footprint assemblages, which are abundantly known from North America, southern Africa, Europe and East Asia, those from the Middle Jurassic are relatively rare (Lockley, 1991a(Lockley, , 1991b(Lockley, , 1998Santos et al., 1994Santos et al., , 2009Gierliński et al., 2009;Hadri et al., 2012;Wagensommer et al., 2012;Xing et al., 2013Xing et al., , 20142015Lallensack et al., 2019). Therefore, dinosaur ichno-associations from this time interval and their taxonomic relationships are still not fully understood. ...
Article
A new dinosaur tracksite is reported from continental red beds of the Jurassic (Late Bathonian-?Callovian) Isli Formation along the northern flank of the Aït Ali ou Ikkou Syncline of the Imilchil area, Central High Atlas, Morocco. The succession was deposited in a fluvio-lacustrine environment, and contains at least fourteen track-bearing levels. The diverse dinosaur-dominated ichnofauna includes the footprints of crocodylomorphs, pterosaurs, theropods, sauropods and ornithischians, together with numerous invertebrate traces. Here, we focus on a long sauropod trackway, which comprises nine consecutive manus-pes sets preserved as concave epireliefs. The low heteropody and asymmetry of manus prints with a large digit I (pollex) impression oriented medially, and a large triangular claw trace, which is posteriorly oriented, are characteristic of the ichnogenus Polyonyx. Different from typical Polyonyx is the narrow gauge pattern compared to the wide gauge observed in the type trackway from Portugal. Additional material from Morocco, similar to Polyonyx, comprises the trackway of a very small (?juvenile) individual found close to the main trackway, as well as a short trackway from a different locality in the Isli Formation. Our data from the Moroccan High Atlas indicates the presence of basal eusauropods in the Middle Jurassic-Early Cretaceous interval in the northwestern part of Gondwana for the first time, and suggests they inhabited a lacustrine paleoenvironment.
... However, more discoveries in 2016 (Xing et al. 2016a) revised the categorization to Type 3b. Middle Jurassic dinosaur records from the Chuanjie Formation, both skeletons and tracks are rare (Xing et al. 2014), and are typical Type 3a. Late Jurassic to Jurassic-Cretaceous boundary records from the Anning Formation are even scarcer, and only include fragmentary skeletal remains of Mamenchisaurus (Fang et al. 2000) and a tetrapod footprint assemblage with possible swim traces (Xing et al. 2016b), categorizable as Type 2b (track-dominated). ...
Article
Late Jurassic dinosaur track assemblages from China are much less common than those reported from the Lower and Middle Jurassic which are heavily dominated by well-known theropod ichnogenera such as Grallator, Eubrontes, Kayentapus, and a few sauropodomorph and ornithischian ichnotaxa. We here report two tridactyl dinosaur morphotypes from the Lufeng Basin in southern China that most closely resemble Late Jurassic Dinehichnus from North America, a probable gracile ornithopod morphotype, and an unnamed avian morphotype reported from rare occurrences in North America and Europe, which we here name as Tridentigerpes ichnogen. nov., accommodating two ichnospecies T. huasibanleei ichnosp. nov. from the Lufeng Basin, and T. pinuelai ichnosp nov., from Spain. These ichnites re-orient our understanding of Late Jurassic dinosaur track distributions in the Late Jurassic of China, which was previously based in large part on very poor material of presumed theropod affinity. Given the sparse body fossil record from southern China including very fragmentary sauropod remains, the ichnological record of diverse bipedal dinosaurs, suggestive of avian and non-avian dinosaurs and ornithopods, the Anning Formation represents a type 2b deposit where tracks are more common than skeletal remains and indicative of faunas not represented by the body fossil record.
... In our comparative statistical analysis, we analyzed the 10 Tafaytour trackways as well as other small-sized sauropod trackways based on data taken from the literature (Lockley et al., 1986(Lockley et al., , 2002a(Lockley et al., , 2002b(Lockley et al., , 2004(Lockley et al., , 2006(Lockley et al., , 2014Lim et al., 1989;Lockley and Santos, 1993;Dalla Vecchia, 1994;Meyer et al., 1994;Gierli nski and Sawicki, 1998;Lee et al., 2000;Dalla Vecchia et al., 2001;Huh et al., 2003;P erez-Lorente, 2003;Day et al., 2004;Nicosia et al., 2007;Marty, 2008;Gonz alez Riga and Calvo, 2009;Castanera et al., 2011;Xing et al., 2011Xing et al., , 2013Xing et al., , 2014aXing et al., , 2014bXing et al., , 2014cXing et al., , 2015aXing et al., , 2016bXing et al., , 2016cXing et al., , 2016dKim and Lockley, 2012;Marty et al., 2013;Fern andez-Baldor, 2015;Mazin et al., 2016), resulting in a total of 79 trackways (Supplementary Data 2). Besides Morocco, the included trackways come from Switzerland, Germany, England, France, Italy, Croatia, Spain, Portugal, China, Korea, the U.S.A., Argentina, and Bolivia and range from the Lower Jurassic to the Upper Cretaceous. ...
Article
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Forelimb posture in sauropod dinosaurs is still poorly understood. Although a laterally directed (semisupinated) manus is the plesiomorphic condition in sauropodomorphs, the sauropod track record prevailingly shows anterolateral to anterior manus orientations, suggesting a high degree of manus pronation. The ?Middle Jurassic Tafaytour tracksites described herein preserve at least 10 trackways, nine of which show laterally oriented, and in two examples even posterolaterally oriented, manual impressions. Located in the Argana Basin of the Western High Atlas, Morocco, the tracksite yields hundreds of footprints on a highly bioturbated surface, including examples with well-preserved digit and claw impressions. Footprint morphology and trackway configuration vary greatly between trackways. A literature review indicates that laterally directed manual impressions are restricted to small- and medium-sized trackmakers. Statistical analysis was performed on a larger sample (n = 79) of small sauropod trackways from around the world, indicating that lateral manual orientations are correlated with low locomotion speeds and narrow trackway gauges. Manus pronation in sauropods is hypothesized to occur when the forelimb is actively contributing to the propulsion of the animal, which would be the case at faster speeds or at wider trackway gauges where the center of mass is located more anteriorly. We present new approaches to the quantitative analysis of trackway data. Mean configuration plots allow for direct graphical comparisons of different trackways. Two types of trackway asymmetries are defined and quantified. The apparent glenoacetabular distance (GAD) represents a feasible proxy for body size, at least for the smaller sauropod trackmakers analyzed herein. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP Citation for this article: Lallensack, J. N., S. Ishigaki, A. Lagnaoui, M. Buchwitz, and O. Wings. 2019. Forelimb orientation and locomotion of sauropod dinosaurs: insights from the ?Middle Jurassic Tafaytour tracksites (Argana Basin, Morocco). Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2018.1512501.
... It is also the case that relatively abundant dinosaur footprints are known from the Lufeng Basin (Xing et al. 2009(Xing et al. , 2016; these mainly include the tracks of mediumsized and small theropods, as well as small ornithopods, and medium-to-large ornithischians. Although trackways are rare, a large number of isolated footprints are known (Xing et al. 2009(Xing et al. , 2014(Xing et al. , 2016; tracks were excluded from our analyses as this bias might compromise bone biomass calculations. ...
Article
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The Lufeng area is a key locality for Early and Middle Jurassic Chinese dinosaurs. This region is perhaps best known internationally for the co-occurrence of basal sauropodomorph-eusauropod dinosaurs and has therefore been an important research area since the 1930s. We review on a series of palaeoecological analyses in this paper and assess biomass, in particular, using skeletal fossils from this region and analyses of large living terrestrial vertebrates as well as new sporopollenin and sedimentary information. The results of this analysis suggest a gradual substitution of basal sauropodomorphs (e.g. Lufengosaurus) by eusauropods (e.g. Chuanjiesaurus) between the Early Jurassic and Middle Jurassic in concert with increasing biomass and decreasing overall faunal diversity.
... Compared with Early and Late Jurassic footprint assemblages, which are abundantly known from North America, southern Africa, Europe and East Asia, those from the Middle Jurassic are relatively rare (Lockley, 1991a(Lockley, , 1991b(Lockley, , 1998Santos et al., 1994Santos et al., , 2009Gierliński et al., 2009;Hadri et al., 2012;Wagensommer et al., 2012;Xing et al., 2013Xing et al., , 20142015Lallensack et al., 2019). Therefore, dinosaur ichno-associations from this time interval and their taxonomic relationships are still not fully understood. ...
Article
Horseshoe crabs (Chelicerata, Xiphosura) from Mesozoic deposits are extremely rare in the fossil record of the African continent. Here we report new evidence of the occurrence of xiphosurans in North Africa. These are horseshoe crab traces, including the ichnogenera Kouphichnium (repichnia) and Selenichnites (fodinichnia and/or domichnia), which have been discovered in Middle Jurassic strata of the Imilchil area (Central High Atlas, Morocco). They are preserved on upper and lower bed surfaces of sandy limestones and marls in the upper parts of the Tislit and Imilchil formations (late Bajocian-early Bathonian). The Selenichnites traces, measuring up to 30 cm in width, co-occur with theropod and birdlike tracks. The reported Kouphichnium is the first record from Mesozoic deposits of Morocco, while Selenichnites is the second occurrence in Jurassic strata of Africa. These ichnogenera evidence different behaviour of horseshoe crabs, i.e. Selenichnites is the result of burrowing activity when searching for food in the sediment, and Kouphichnium is a regular locomotion trace left on the sediment surface, occasionally leaving an impression of the telson. The combination of sedimentological data and ichnological analysis indicates a shallow-water subtidal depositional environment preceding the Bathonian regression of the Atlas domain. Palaeobiogeographically, the discoveries indicate the presence of horseshoe crabs at the southern margin of the Tethys. Furthermore, they enhance our knowledge of their previously scarcely documented distribution in Gondwana during the Mesozoic.
... All Cretaceous sauropod tracks in southwest China have been referred to Brontopodus (Xing 2016;Xing and Lockley 2016). Some of the Middle Jurassic tracks are have also been referred to Brontopodus, such as the large sauropod tracks from the Middle Jurassic Chuanjie Formation of Lufeng County, Yunnan Province (Xing et al. 2014a), and variously-sized tracks from that certain aspects of its anatomy (e.g. proportionally low, nonpneumatized dorsal neural arches and a three-vertebra sacrum) may preclude its inclusion within Sauropoda. ...
Article
The newly discovered large (350 m²) Yantan dinosaur tracksite, in the Lower Jurassic Ziliujing Formation of Guizhou Province, China, reveals at least 250 footprints of which ∼97 can be resolved into trackways of sauropodomorphs. All the trackways are sub parallel likely indicating gregarious behavior. One theropod track (cf. Grallator) was recorded. The sauropodomorph tracks predominantly represent quadrupedal progression (Morphotype A), and footprint morphology is similar to the ichnospecies Liujianpusshunan, characterized by outward pes rotation. Three trackways indicate bipedal progression, and two of these (Morphotype B) indicate inward pes rotation, accompanied by elongate pes digit scratch marks. For the latter phenomenon three possible scenarios are discussed: (1) significant rotation changes accompanying changes in gait, (2) swimming behavior, (3) formation of undertracks. Sedimentological evidence indicates the tracks were made on a linguloid rippled, muddy, immature sandstone substrate characterized by significant differences in substrate consistency across the track-bearing surface. Microbially induced sedimentary structures (MISS) characterized by distinctive wrinkle marks indicate a stressed, probably semi-arid, paleoenvironment that was not conducive to habitation by invertebrate organisms. This is consistent with other evidence that Lower Jurassic sauropodomorph tracks are often associated with semi-arid paleoenvironments. © 2018 China University of Geosciences (Beijing) and Peking University
... Most sauropod tracks from China are known from Lower Cretaceous sediments in the northern and southwestern parts of the country (Lockley et al. 2014), as well as from various Jurassic deposits, e.g., at the Beikeshan tracksite in Lufeng County, Yunnan Province (Xing et al. 2014a). Only two Upper Cretaceous sauropod track sites are currently known in China: the Yuanjitun site (Chen and Huang 1993) and the Wadi site, Sichuan Province (Xing et al. 2015). ...
Article
Type specimens of the sauropod ichnotaxon Chuxiongpus changlingensis, which was later reassigned to Brontopodus changlingensis, as well as the theropod ichnotaxon Yunnanpus huangcaoensis, both from the Cretaceous Jiangdihe Formation of Yunnan Province, are redescribed in order to document their morphological features. Both, but particularly Y. huangcaoensis, which is considered now a nomen dubium, were originally based on poorly preserved material. Nevertheless, the specimens document a saurischian dominated biota that existed during the deposition of the Jiangdihe Formation from which no skeletal remains are known. B. changlingensis trackways were left by small sauropods that show consistent partial or complete overprint of the manus by the pes. This pattern makes it difficult to calculate manus length, and heteropody can be only estimated.
... In recent years, abundant new discoveries of dinosaur footprints have been made in China, such as the Early-Middle Jurassic tracksites in Yunnan Province (Xing et al., 2013a(Xing et al., , 2014a(Xing et al., , 2016a, Sichuan Province (Xing et al., 2015a(Xing et al., , 2016b, the Early Cretaceous tracksites in Shandong Province (Li et al., 2011;Chen et al., 2013;Kuang et al., went to the tracksite and conducted a detailed study of tracks and also paid particular attention to the sedimentary features of the trackbearing levels. The aims of this paper are: (1) to describe the morphology of sauropod tracks and trackways; (2) to analyze the sedimentary environment of the tracksite, (3) to analyze the possible track makers and their behavior; (4) to reconstruct the paleoenvironments and (5) discuss the effect of arid environments on the paleogeographical dispersions of the Late Jurassic dinosaur fauna in North China. ...
Article
This paper presents the first report of sauropod tracks from the Upper Jurassic of Shanxi Province, China. Dinosaur tracks appear concentrated in five trackways, in different stratigraphic levels of the Late Jurassic Tianchihe Formation. Tracks are dominantly small and medium-size sauropod tracks and are tentatively assigned to Brontopodus based on preserved track morphology, trackway pattern and statistical analysis. The Tianchihe Formation in which the tracks appear shows a gradual change from meandering fluvial to sandy braided fluvial depositional systems developed in a seasonally arid environment. Comparisons of the evaluated speed of bipedal to quadruped trackways indicate that the slower walk more easily produces pes-dominated overprints. Trackways in the Guxian tracksite appear following different orientations, suggesting that these trackways were produced by different sauropods at different times. An unusual trackway following a curved pattern has been identified in the site and could represent a special locomotion character or a social behavior. The presence of eolian deposits in central Shanxi Province could have acted as a paleogeographic and paleoenvironmental barrier for the dispersion of the Yanliao Biota that survived in northern Hebei-western Liaoning and northestern Shanxi Province to the Ordos Basin during the Late Jurassic.
... All Cretaceous sauropod tracks in southwest China have been referred to Brontopodus (Xing 2016;Xing and Lockley 2016). Some of the Middle Jurassic tracks are have also been referred to Brontopodus, such as the large sauropod tracks from the Middle Jurassic Chuanjie Formation of Lufeng County, Yunnan Province (Xing et al. 2014a), and variously-sized tracks from that certain aspects of its anatomy (e.g. proportionally low, nonpneumatized dorsal neural arches and a three-vertebra sacrum) may preclude its inclusion within Sauropoda. ...
Article
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.
Article
Two newly discovered dinosaur track locations near the town of Bijie in Guizhou Province, southwestern China are named the Yuanbaoqing and Yejiatian tracksites. They represent the Lower Jurassic Maanshan Member of the Zijiujing Formation and Upper Jurassic Xiashaximiao Formation, respectively. The former Yuanbaoqing tracksite reveals a minimum of three Anomoepus trackways and two poorly preserved incomplete sauropod trackways, tentatively assigned here to cf. Brontopodus. They occur in shallow lake to shoreline facies depositional environments. The Yejiatian site shows a well-preserved, narrow-gauge sauropod trackway in a delta plain facies which is identified as Parabrontopodus. The occurrences enhance the local faunal record in Guizhou Province were previous tracksite reports for these stratigraphic intervals are sparse. In the broader regional context of southwestern China the track record is consistent with the body fossil record in both the Lower and Upper Jurassic of this region.
Conference Paper
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The transect from Jones Ranch Quarry, west of the town of Glen Rose, to the Arlington Archosaur Site, in the heart of the Dallas-Fort Worth Metroplex, spans 20 million years of the middle Cretaceous. These sediments lie at the base of a larger section in north-central Texas with near continuous sedimentation to the end of the Maastrichtian. At an even grander scale this is a small part of Cretaceous strata that crop out extensively across the state, forming a broad band roughly parallel with the present day coast of the Gulf of Mexico. This field trip visits Cretaceous strata in the Fort Worth Basin, that is one of the main archosaur fossil-bearing regions of the state.
Book
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The nature of this book is indicated by its title: it is an Atlas, with a relatively high number of illustrations (text-figures, maps, plates). It is an annotateci Atlas, because illustrations are supplemented by concise text for each locality where tetrapod ichnofaunas have been found (120), according to information at my disposal. Why do an ichnological Atlas on Latin America? It is just a cultural and linguistic region. However, Latin America is not an uniform region neither from the geographical, nor from the geotectonical points of view. The point is that Latin America has a great number of tetrapod tracksites, from the Devonian to the Recent in origin, with tracks of amphibians, reptiles, birds and mammals. However, many of them are just locally known. Information on many of these sites has not been published; others have been described in locai journals, practically unknown abroad. Sometimes the discovery of tracksites was issued only in newspapers. Frequently, publications are poorly illustrated. Good photographs are rare, and authors seldom publish drawings and photographs of the same material. I must add that communication is (1994) poor between Latin American paleontologists and their colleagues in other countries. As a result, the vertebrate ichnology of Latin America is almost unknown. The idea struck me, and took my fancy, that there is room, and even need, for one Atlas of Latin America tetrapod tracksites. There exists neither a synthesis nor a revision of this subject, and on a planetary scale Latin American material is poorly recorded. So I began collecting data and visiting localities. But I must say that I began to collect material before knowing how many tracksites there are in Latin America. If I had known how many years I would need to complete this book, I would never have began at all. This Atlas is intended to open a window on an almost new world to our colleagues of the Laurasia and of the other Gondwana continents. It could also spur on Latin American ichnologists, paleontologists and geologists to join their efforts, continue their research in this fascinating field, and to start work in those countries where tetrapod ichnology is not practiced. For coherence between the study of tossii icnofaunas and palaeogeography, the body of the work and the bulk of the excursuses concern South America. Tracksites of Mexico, Central America and the Antarctic islands of South American influence are organized in Appendix. There was not intention to present a complete description of all the fossil tracks of Latin America, nor to illustrate all of them. That would be too long and too difficult. The goals were to provide information on all the tracksites known to this author, to furnish general notices on geographic and geologic location, to list more or less completely the trackways and footprints, their history and references. I did not give complete information on sites that are well described in accessables publications; nor on ichnofaunas on which monographs are being prepared. I included also some doubtful notices on tracksites and tracks that I could not visit, and whose existence I could not check. This synthesis and revision began in November 1974, and lasted almost fifteen years, during which time I visited most of the localities in South and Central America, and examined in the field and/or in collections almost all of the material. Sometimes the slabs were pursued to museums on other continents, where they had been taken. To achieve this purpose, more than eighty expeditions were necessary to three countries of Central America, ten of South America, two of Europe, and one of North America. Information on other localities was available in publications, unpublished reports, field notebooks, unpublished manuscripts and verbal or epistular information from colleagues, travellers, engineers, amateurs, hunters and farmers. Journeys were achieved by piane, ship, car or bus, but also on horseback, long treks on foot or in unsafe boats. One could write a book on “South American Adventure” on these fifteen years of passion-ridden field work, in which boredom had no place. Instead, the chosen literary genre is quite different: a series of files that present data systematically, following a set pattern, accompained by generai and local maps, and by numerous text-figures and plates. The book may be much criticized for many reasons, for which the indulgence of the reader, or perhaps I should say, the user, is requested. The book makes almost no attempt at any systematic stratigraphic correlation between trackway sites. This is not a book on Latin American Phanerozoic stratigraphy. The data, especially those on stratigraphy, lithology, palaeoenvironments and dating, have different sources from different times and could not always be updated. It was not possible, because of the cost, to furnish drawings and/or photographs of all the specimens. Often, drawings and photos are presented in alternate ways. The plates were organized to illustrate mainly unpublished material or specimens that were not illustrated, or were poorly illustrated in earlier papers. However, it is plain that the illustrative documentation is far from complete. The author hopes to give no false, exaggerated, or unfair impression of all that is available for study, of which the plates selectively illustrate a relatively tiny pari. It would be interesting to give a complete description of the specimens. However, this would lead to an excessively thick publication. This paper at least points to the sources for more complete study. Brasília, Brazil, May 2, 1989
Article
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Late Jurassic material of small theropod and ornithopod dinosaur footprints are reported from the northeastern slope of the Holy cross Mountains, Poland. the ichnites occur in five lithostratigraphical units of an epicontinental basin in central Poland. Small theropod tracks, Wildeichnus isp. and Jialingpus isp., came from the bałtów Platy Limestones, bałtów coral Limestones and wierzbica Oolite and Platy Limestones. Four specimens of small ornithopod footprints, assigned to Dinehichnus isp., were found in the błaziny Oolite Limestones and wierzbica Oolite and Platy Limestones. a medium-sized ornithopod footprint, identified as cf. Dinehichnus isp., was discovered in the Ożarów Oolite and Platy Limestones. the described footprints from the Upper Jurassic of Poland are smaller than similar types of ichnites from other parts of the world. the Polish Late Jurassic dinosaur community probably represented a diminutive insular fauna.
Article
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Three sauropod trackways comprise eight tracks that resemble Brontopodus tracks have been found at the Morong track site in Changdu Prefecture, Tibet, China. These wide-(or sub-wide)-gauge tracks suggest that there was a large sauropod, possibly a member of Titanosauriformes, in Changdu Prefecture during the Early-Middle Jurassic. The sauropod fauna from Changdu Prefecture, Tibet not only has elements in common with the sauropod fauna from the Sichuan Basin, but may include more diverse faunal components.
Article
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Almost all dinosaur tracks in Poland come from three lowermost formations of the Lower Jurassic in the Holy Cross Mountains: Zagaje Formation, Skloby Formation and Przysucha Ore-Bearing Formation. Floristic remains and sequence stratigraphy correlation indicate the Hettangian age of all three formations. They represent various continental and marginal-marine environments. Fluvial and lacustrine sediments dominate in the continental Zagaje Formation, while the nearshore and deltaic facies are dominant in the two overlying formations. Various ornithischian, sauropod and theropod tracks occur in these sediments. Parallel sauropod trackways reported herein are the earliest record of sauropod gregarious behavior. Moreover, the present paper summarises and systematises the whole existing material, addressing the ichnosystematic and preservational aspects. Dinosaur tracks assemblages are assigned to three parts of the lithostratigraphical succession in which they occur and are discussed against their palaeoenvironmental background. Two general assemblages are distinguished: lower Zagaje assemblage of an inland, humid habitat with both low- and high-growing vegetation, dominated by high browsing herbivores (sauropod trackmakers of Parabrontopodus) and medium- to large-sized predators (theropod trackmakers of Anchisauripus and Kayentapus), and upper Zagaje-Skloby-Przysucha assemblage, representing deltaic plain-shoreline habitats with low, dense vegetation, dominated by low browsing herbivores (ornithischian trackmakers of Anomoepus and Moyenisauropus), associated by small- to medium-sized predators (theropod trackmakers of Grallator and Anchisauripus). Dinosaur ichnofauna from Poland rather poorly reflects biostratigraphical vertebrate faunal change in Early Jurassic time, but it does reflect environmental and biogeographical differences quite well. The discussed data imply also a high dinosaur phylogenetical diversity as early as in the Hettangian age.
Article
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After the discovery of Early Jurassic sauropod tracks in northern Italy, Polish Liassic strata revealed a second comparably early record of sauropod footprints in Europe. In comparison with the Italian material, described tracks seem to be left by juvenile or small primitive sauropods, presumably 4.4 m and 5.5 m long.
Article
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Herein we describe three and one half footprints that pertain to Grallator isp. from the Lower Cretaceous Yixian Formation, Sihetun, Liaoning Province, China. This is the first description of dinosaur footprints from the Yixian Formation. The tracks were left by at least three individual track makers. It is estimated from the tracks that the body lengths of the track makers were 1.51 m, which is the average length of known theropods from the Yixian Formation. The feet of Caudipteryx and Sinosauropteryx were reconstructed. The former was more similar than the latter to the Grallator isp. track outlines. Feet capable of registering Grallator morphotype tracks may therefore have been widely distributed in small-medium sized theropods (other than dromaeosaurids and troodontids) from the Yixian Formation.
Article
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Since their discovery two decades ago, moderately-large, problematic tetrapod footprints, made by a large quadruped, from the upper part of the Upper Triassic Chinle Group in western North America, have posed ichnotaxonomic problems, as well as generating uncertainty about the affinity of the track maker. In the 1980s, they were tentatively considered to be of chirotheriid affinity on the basis of manus morphology, and provisionally labeled Chirotherium isp., but even from the outset, the pes was recognized as similar to that of a small sauropod. In the 1990s, the Chirotherium label was abandoned, and the South African ichnotaxon Tetrasauropus was tentatively applied, implying a sauropodomorph affinity for the track maker. However, due to ichnotaxonomic problems, the label was never formally applied or considered satisfactory. Moreover, at that time there were no sauropods known from the Late Triassic, and diagnostic body fossil evidence of sauropodomorphs was sparse or absent in the Chinle Group. In the 2000s, however, Late Triassic sauropods were reported, and efforts were made by several groups to re-investigate the type material of Tetrasauropus and related ichnotaxa (such as Pseudotetrasauropus) held in the collections of Paul Ellenberger at Montpellier, France. The result of these investigations is a growing consensus that North American " Tetrasauropus " (referred to informally by some authors in quotation marks) is best accommodated in a new ichnotaxon. We herein erect the ichnotaxon Eosauropus cimarronensis ichnogen. et ichnosp. nov. to accommodate this track type and suggest that the few other Northern Hemisphere reports of " Tetrasauropus " also be transferred to Eosauropus. This taxonomic revision does not imply that Eosauropus (formerly North American " Tetrasauropus ") is of undoubted sauropod affinity. However, many recent authors have supported this suggestion, with varying degrees of enthusiasm, and have incorporated extensive discussion of this ichnotaxon and its morphological characteristics into their analyses of sauropod and/ or sauropodomorph phylogenies and inferences about the locomotor evolution of these groups. We hold the position that the morphological similarities between the Eosauropus pes and those of well-documented, post-Triassic sauropods is noteworthy but by no means absolute. If the Eosauropus track maker was not a sauropod, the footprints are an interesting example of convergence.
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New discoveries, revision of existing taxa and the application of cladistic analysis have all shed light on the relationships of basal sauropodomorphs. Nevertheless, the interrelationships proposed in recent studies have varied widely, with some authors advocating the view that Prosauropoda and Sauropoda are monophyletic sister-taxa, whereas others favour an extreme form of prosauropod paraphyly with respect to sauropods. A data set comprising 292 characters for seven outgroups and 27 ingroup sauropodomorph taxa is presented and analysed. The most parsimonious trees suggest that Efraasia, Mussaurus, Thecodontosaurus and Saturnalia are increasingly more distant sister-taxa to the remaining sauropodomorphs. The latter are divided into two monophyletic sister-groups: a plateosaurian clade containing Plateosaurus, Lufengosaurus, Massospondylus, Coloradisaurus and others, and a sauropod clade, which includes melanorosaurs (near its base), Antetonitrus, Chinshakiangosaurus, Vulcanodon, Barapasaurus and eusauropods. Bootstrap values and constrained analyses with Templeton's tests indicate that support for many of the proposed relationships is relatively weak. This results from the inclusion of poorly known taxa, such as Blikanasaurus, and from considerable levels of character conflict. Character mapping indicates several apomorphic features that support the monophyly of a plateosaurian clade or subgroups within it. In addition, it appears that approximately 20 apomorphies are acquired early in basal sauropodomorph evolution, but are reversed to the plesiomorphic state in basal sauropods and eusauropods. Aside from their impact on phylogenetic uncertainty, these reversals may reflect important aspects of early sauropod evolution that relate to shifts in the ecological niches occupied by these taxa.
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“Splitting” and “lumping” are perpetual problems in vertebrate, especially dinosaur, ichnotaxonomy. Chinese dinosaur ichnotaxonomy, which began in 1940, provides a series of interesting case studies, highlighting the dual problems of historical and dubious ichnotaxonomy. Chinese Mesozoic tetrapod track types have been placed into 63 ichnospecies (one Triassic, 28 Jurassic, and 34 Cretaceous), exclusive of other, non-type ichnospecies or ichnotaxa identified from China. Fifty-two (∼83%) of these 63 tetrapod ichnospecies were placed in monospecific ichnogenera. At the ichnogenus level, we prune—either by recognizing nomina dubia or by synonymy—17 from the list of 53 dinosaurian ichnogenera (a 32% reduction), leaving 36 ichnotaxa that we consider valid. Most of the cuts affect Jurassic theropod ichnotaxa, which are reduced from 23 to only nine because most ichnogenera are subjective junior synonyms of Grallator and Eubrontes. Fewer Chinese Cretaceous ichnotaxa (only six of 21 ichnogenera) are obvious nomina dubia or subjective synonyms, suggesting greater east Asian endemism during this time. Because ichnospecies differences are subtle, we provisionally retain ichnospecies as valid pending detailed comparative analyses of congeneric ichnospecies. This synthesis is long overdue and is necessary to address problems of historical and provincial ichnotaxonomy, which severely hamper comparisons of tetrapod ichnofaunas in space and time.
Article
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A dinosaur footprint assemblage from the Lower Jurassic Ziliujing Formation of Zigong City, Sichuan, China, comprises about 300 tracks of small tridactyl theropods and large sauropods preserved as concave epireliefs (natural molds). The theropod footprints show similarities with both the ichnogenera Grallator and Jialingpus. Three different morphotypes are present, probably related to different substrate conditions and extramorphological variation. A peculiar preservational feature in a morphotype that reflects a gracile trackmaker with extremely slender digits, is the presence of a convex epirelief that occurs at the bottom of the concave digit impressions. It is possibly the result of sediment compaction underweight load when the pes penetrated the substrate, being a resistant residue during exhumation and weathering. The sauropod tracks belong to a trackway with eight imprints consisting of poorly preserved pes and manus tracks and a better preserved set, probably all undertracks. The narrow-gauge trackway pattern resembles the ichnogenus Parabrontopodus well known from the Jurassic but other features such as the minor heteropody are different. The assemblage enriches the dinosaur record from the famous Zigong locality and the evidence from the Lower Jurassic in this area that was restricted to a few skeletal remains and footprints. Furthermore it proves the presence of small theropods, whereas skeletons of the group, well- known from the Middle-Upper Jurassic of Zigong, are of medium to large size only. Remarkable is the dominance of saurischians in these assemblages, which is characteristic of Jurassic dinosaur communities whereas the Cretaceous record shows an increase of ornithopod groups. An overview of the dinosaur trace and body fossil record of the Sichuan Basin supports this view. The paleoenvironment can be designated as a low-latitude tropical freshwater lake as it is indicated by bivalve shells.
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Theropod footprint assemblages from the Sanjianfang Formation (Middle Jurassic) at the Shanshan tracksite, Turpan City, Xinjiang, northwest China are documented and re-described in detail. Together with new discoveries from this locality, they shed light on the different preservation and extramorphological variation of a total of 143 footprints. Ichnotaxonomically, they are assigned to the ichnospecies Changpeipus carbonicus, well known from other Jurassic tracksites of China. The presence of two distinct morphotypes, as has been proclaimed in earlier studies, is related to extramorphological variation on surfaces that indicate a soft, wet and slippery substrate. Anatomically based features supporting different ichnospecies are not present. Furthermore, the comparison with similar footprints from other localities suggests a monotypic ichnogenus Changpeipus with the type species C. carbonicus. Footprint lengths of 12.2 cm (a few isolated examples) to 47 cm at the Shanshan tracksites reflect small to medium-sized trackmakers that can be interpreted either as different age classes or different biological species. Peculiar preservational features include a footprint that documents slipping movement of the pes by three parallel bands obviously reflecting digits II, III and IV. An associated “normally” impressed tridactyl footprint suggests that both constitute a single step. The depositional environment was a gradually expanding and deepening lacustrine setting. This is also supported by the co-occurrence of abundant invertebrate trace fossils. Contrary to earlier interpretations resulting in an assignment to Lockeia the invertebrate traces are re-assigned here to the ichnogenus Fuersichnus that can be attributed to deposit-feeding insect larvae or other invertebrates. Fuersichnus is a characteristic dwelling and/or feeding burrow of muddy floodplains or lake margin settings.
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Pathological or traumatic loss of teeth often results in the resorption and remodeling of the affected alveoli in mammals. However, instances of alveolar remodeling in reptiles are rare. A remodeled alveolus in the maxilla of the Chinese theropod Sinosaurus (Lower Jurassic Lower Lufeng Formation) is the first confirmed example of such dental pathology in a dinosaur. Given the known relationship between feeding behavior and tooth damage in theropods (teeth with spalled enamel, tooth crowns embedded in bone) and the absence of dentary, maxillary, and premaxillary osteomyelitis, traumatic loss of a tooth is most likely the cause of alveolar remodeling. Based on the extent of remodeling, the injury and subsequent tooth loss were non-fatal in this individual.
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The classic Early Jurassic age theropod footprints Eubrontes giganteus, Anchisauripus sillimani, and Grallator parallelus were established by Edward Hitchcock in 1836–1847 and are the type ichnospecies of their respective ichnogenera. We identify, describe, and figure the type specimens in detail for the first time since they were named. We also figure and describe the other elements of the type series as well as specimens mistakenly thought to be the types. All of the tracks come from cyclical lacustrine and marginal lacustrine to fluvial strata from an interval spanning about one million years in the Early Jurassic age Meriden and Agawam groups of the Hartford and Deerfield basins of Connecticut and Massachusetts. Based on osteometric comparisons with skeletal material, these three ichnospecies were most likely made by theropod dinosaurs, as usually assumed. Although treated here as distinct ichnogenera, it is possible that their major proportional differences derive from allometric growth with individuals of several related species in one genus or even within one species of trackmaker. The rigorous establishment of these classic ichnological taxa forms a basis for more wide ranging studies of theropod diversity in the early Mesozoic.
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: A new theropod dinosaur, Shidaisaurus jinae gen. et sp. nov., has been described on the basis of an incomplete skeleton. The specimen was found near the base of the Upper Lufeng Formation (early Middle Jurassic) in Yunnan, China. It is the first theropod dinosaur from the Middle Jurassic of Yunnan. Shidaisaurus jinae is distinguishable from other Jurassic theropods by certain features from the braincase, axis, and pelvic girdle. The absence of any pleurocoels in the axis or in any anterior dorsal vertebrae suggests that the new Lufeng theropod is relatively primitive and more plesiomorphic than most of the Middle to Late Jurassic theropods from China. Most Chinese taxa of Jurassic theropod dinosaurs have not been well described; a further detailed study will be necessary for us to determine their phylogenetic relationships with Shidaisaurus jinae.
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Large theropod and sauropod footprints predominated in the continental Zagaje Formation (early Hettangian) exposed in the Sołtyków outcrop. Geological and paleobotanical data indicate an inland seasonal habitat with low and high growing vegetation on the flood plain. The theropod-sauropod ichnofauna also contains occasional footprints of small ornithischians and mammals. The Sołtyków track assemblage, together with other similar assemblages, suggests a wide range of habitats occupied by sauropods.
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Two major ichnotypes of sauropod trackways have been described: "narrow-gauge," in which both manus and pes prints approach or intersect the trackway midline, and "wide-gauge," in which these prints are well apart from the midline. This gauge disparity could be the result of differences in behavior, body size, or morphology between the respective trackmakers. However, the biomechanics of locomotion in large terrestrial vertebrates suggest that sauropods were probably restricted in locomotor behavior, and the lack of systematic size differences between footprint gauges argues against body-size-related influences. We argue that skeletal morphology is responsible for gauge differences and integrate data from locomotor biomechanics and systematics with the track record to predict the hindlimb morphology of wide-gauge trackmakers. Broader foot stances in large, graviportal animals entail predictable mechanical consequences and hindlimb modifications. These could include outwardly angled femora, offset knee condyles, and a more eccentric femoral midshaft cross-section. A survey of sauropod hindlimb morphology reveals that these features are synapomorphies of titanosaurs, suggesting that they were the makers of wide-gauge trackways. The temporal and geographic distribution of titanosaurs is consistent with this hypothesis because wide-gauge trackways predominate during the Cretaceous and are found worldwide. Additional appendicular synapomorphies of titanosaurs are interpreted in light of identifying these animals as wide-gauge trackmakers. We suggest that titanosaurs may have used a bipedal stance more frequently than did other sauropods. These correlations between ichnology, biomechanics, and systematics imply that titanosaurs were unique among sauropods in having a more varied repertoire of locomotor habits.
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The narrow- and wide-gauge trackways attributed to sauropod dinosaurs are hypothesized to be a consequence of the relative positions of their centers of mass. This hypothesis was tested using three-dimensional, trackway-producing computer models of two sauropods and studies of Asian elephants. Centers of mass of sauropod models were computed using density distributions that reflect the high degree of pneumatization of the skeletons and air sacs within the body. A close correspondence was found between the relative areas of hand and foot prints in different trackways and the relative fractions of the body weight borne by the forefeet and hindfeet in the different types of sauropods inferred to have made the trackways. Experimental studies of Asian elephants corroborated the close correspondence between relative areas of the hindfeet and forefeet and body weight distribution. Replicating actual sauropod trackways with the walking models enabled testing of proposed gaits for a sauropod model. Brachiosaurus brancai, with its more centrally positioned center of mass, was stable and possessed a wide safety margin only when replicating a wide trackway. Conversely, Diplodocus carnegii, with a more posteriorly placed center of mass, was most stable when replicating a narrow trackway. A trend for large sauropods (>12 tons), independent of clade, to have more anteriorly positioned centers of mass was identified, and it is proposed that all large sauropods were restricted to producing wide-gauge trackways for stability reasons. The primitive gait state for Sauropodomorpha was determined to be one that produced narrow-gauge tracways.
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Lufengopus dongi, a new ichnogenus and ichnospecies of theropod dinosaur footprint is erected. The holotype is from the Upper Lufeng Formation of the Middle Jurassic, Lufeng County, Yunnan Province of southern China. Lufengopus dongi gen. et sp. nov. is characterized by its large size (the maximum length is approximately 40 cm), and relatively wider width between the second and fourth toes, the ratio of the maximum length to width of the footprint is 1.25. The discovery of the large-sized theropod dinosaur footprint provides a strong evidence for the potential findings of large theropod dinosaur bones in this area, although till now, no theropod dinosaur body fossil corresponding to this footprint size has been found.
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The present study re-evaluates Chuanjiesaurus anaensis Fang et al., 2000 from the Middle Jurassic of Lufeng, Yunnan, Southwest China. The holotype and a new referred specimen are described in detail, and re-examined osteologically and phylogenetically. In this report, the author proposes several emended diagnoses based on close observations and comparisons of the specimens. Some osteological features reveal that Chuanjiesaurus belongs to Mamenchisauridae. Compared to other mamenchisaurid dinosaurs, C. anaensis possesses relatively primitive characters. The phylogenetic position of C. anaensis was determined according to the present analysis. In addition, the data sets of some taxa of Mamenchisauridae from southwestern China are modified in the present research. The present analysis reveals that C. anaensis, Mamenchisaurus, Tienshanosaurus and Yuanmousaurus constitute a monophyletic group that belongs to relatively derived Eusauropoda. This suggests that Mamenchisauridae could be positioned at a more derived part of Eusauropoda than previously thought. This study confirms that C. anaensis is a member of Mamenchisauridae.
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Yunnanosaurus youngi sp. nov. is erected based on the following characters: the distal ends of the sacral ribs expanded anteroposteriorly and dorsoventrally, forming into a sacrocostal yoke, which is contacting with the inner surface of ilium; the ischium is longer than the pubis. Yunnanosaurus youngi is about 13 meters long, which is longer than Yunnanosaurus huangi (7 meters long). The height exceeding the length for the centra of the posterior dorsal and anterior caudal vertebrae may be a synapopmorphy of Yunnanosauridae and Melanorosauridae. Yunnanosaurus youngi is stratigraphically younger than Y. huangi and it represents a derived form of yunnanosaurids.
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The second find of sauropod tracks from the Early Jurassic strata of Poland is reported. Sauropod trackway referred to the ichnogenus Parabrontopodus Lockley, Farlow, Meyer, 1994 has been discovered in the early Hettangian of Soltykow, on northern slope of the Holy Cross Mountains.
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About 55 Ma ago, the India plate collided with the Asian plate, forming the E-W-trending Yarlung Zangbo drainage system and Himalaya mountain range. According to recent studies, the authors propose the following new view: a similar collision between the above-mentioned plates had already taken place 200 Ma ago (in the Early Jurassic), which put a Gondwana dinosaurs fauna originating in Africa and South America on the Asian continent, forming a Lufengosaurus -Shunosaurus-Omeisaurus-Mamenchisaurus fauna in southwestern China. This event not only brought Asia dinosaurs but also gave tue to the S-N-trending Hengduan Mountains and such longitudinal drainage systems as the Irrawaddy River, Nujiang River, Lancang-Mekong River and Jinsha. River in South Asia and the Sichuan basin in China.
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The name Brontopodus birdi is assigned to sauropod footprints from the Glen Rose Limestone (Lower Cretaceous) and equivalents of Texas and Arkansas. The ichno-taxon is characterized by: U-shaped manus prints, probably made by a hand in which digits II-IV were bound together in a pad and set off from digits I and V; no claw marks on manus tracks; large, laterally directed claw marks on digits I-III of the pes; outward rotation of manus and pes tracks relative to the direction of travel; a relatively broad trackway, in which footprints do not impinge on the trail midline, and in which the outer limits of the trackway are defined by the pes footprints, rather than the manus tracks; step angles usually 100-120°; tail marks rare or absent. The trackmaker is interpreted as a brachiosaurid, perhaps Pleurocoelus. -Authors
Chapter
The criteria used to define the gaits of living animals cannot be applied very easily to skeletons or trackways. Consequently the gaits of dinosaurian trackmakers are defined arbitrarily on a scale of relative stride length, λ/h, where λ represents length of stride and h represents the trackmaker's height at the hip. Analysis of trackway data confirms that bipedal dinosaurs favored a walking gait with λ/h about 1.3. There is no convincing evidence that bipedal dinosaurs ever used a ricochetal (hopping) gait. Quadrupedal dinosaurs may have been restricted to a slow walking gait, with λ/h <1.0. Semibipedal dinosaurs (ornithopods, prosauropods and, perhaps, some theropods) adopted a somewhat sprawling and low-slung gait while progressing slowly on all fours, but reverted to a normal bipedal gait for faster progression. -from Author
Chapter
This chapter examines the evolutionary relationships of sauropods using cladistic analysis. It also describes in the detail their paleobiology, taphonomy, and paleoecology. Sauropod dinosaurs include the largest terrestrial animals ever to have existed. At present, Sauropoda comprises twenty-two genera. Sauropods have small skulls in relation to their body size, extremely elongate necks and tails, columnar limbs, and stout, barrel-shaped bodies. Sauropod remains have been recovered from all continents except Antarctica. They are found in mass accumulations (bone beds) in the Morrison Formation of the western United States, in the Tendaguru Beds of East Africa, in the Kota Formation of India, in the Lower Shaximiao Formation of the Sichuan Basin in China, and in the Cañodon Asfalto Formation of Patagonia.
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Many sauropod ghost lineages cross the Middle Jurassic, indicating a time interval that requires increased sampling. A wide taxonomic spectrum of sauropodomorphs is known from the Middle Jurassic of China, but the braincase of a new sauropod, named here Nebulasaurus taito gen. et sp. nov., is distinct. Nebulasaurus is sister taxon to Spinophorosaurus from the Middle Jurassic of Africa and represents a clade of basal eusauropods previously unknown from Asia. The revised faunal list indicates dramatic transitions in sauropodomorph faunas from the Jurassic to Cretaceous of Asia; these are consistent with geographic isolation of Asia through the Late Jurassic. Non-sauropod sauropodomorphs, non-ma-menchisaurid eusauropods (including basal macronarians), and mamenchisaurids successively replaced previous grades through the Jurassic, and titanosauriforms excluded all other sauropod lineages across the Jurassic–Cretaceous boundary.
Article
: A new mamenchisaurid dinosaur, Eomamenchisaurus yuanmouensis gen et sp. nov. is erected based on an incomplete skeleton from the Zhanghe Formation, the Middle Jurassic of Yuanmou, Yunnan Province. The new taxon is characterized by absence of pleurocoels in dorsal vertebrae and the dorsal verterbrae with slightly convex anterior articular surfaces, moderately concave posterior articular surfaces; the fourth trochanter is developed posteromedially on the femur; length ratio of the tibia to the femur is approximately 0.64; and the shaft of the ischium is rod-like. Two fused centra of the posterior dorsal vertebrae (the presumed 9th and the 10th dorsal vertebrae) are similar to those in other mamenchisaurid dinosaurs, including Mamenchisaurus hochuanesis, M. youngi and Chuanjiesaurus anaensis. Therefore, fusion of centra of the ninth and the tenth dorsal vertebrae can be recognized as a synapomorphic character of the Mamenchisauridae.
Article
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.
Article
Theropod footprints from the Middle Jurassic Xincun Formation in the Panxi region (Sichuan Province, Southwest China) show strong similaritiesto the ichnogenus Kayentapus. They are characterized by slender digits, wide digit divarication, and a characteristic pad configuration that is differentfrom other Jurassic theropod ichnotaxa. At the Shansong tracksite, three trackways are present, each consisting of four consecutive tracks (strideand pes lengths up to 200 cm and 36 cm, respectively). The speed of the trackmakers has been calculated with values between 1.1 and 1.4 m/s. Theassemblage is a further document of a Middle Jurassic occurrence of this morphotype that is basically known from the Lower Jurassic depositselsewhere. This could be due to peculiarities of theropod communities in this region, reflecting a different paleobiogeographic distribution patternin the Middle Jurassic. Biostratigraphically, ostracods lend support to a Middle Jurassic age of the trackbearing unit. This corresponds partlywith data from the Shangshaximiao Formation that is considered to be of Middle Jurassic age based on ostracods but Late Jurassic age based onvertebrate skeletons. The ichnological record and the presence of Kayentapus-like footprints in both units support a Lower–Middle Jurassic age.
Article
New dinosaur track assemblages were discovered recently in the Tianjialou Formation of the Lower Cretaceous Dasheng Group in Shandong Province, China. Theropods are represented by the trackways of two different medium-sized groups: (1) tridactyl tracks with a typical mesaxonic shape; (2) functionally didactyl tracks attributed to deinonychosaurian theropods. The latter report, the third from the Cretaceous of Shandong Province, enlarges the global record of didactyl theropod tracks, until now sparsely documented from only a few locations in Asia, North America and Europe. A number of features in the dromaeosaur trackway suggest the assignment to cf. Dromaeosauripus. Several medium-sized trackways resemble the narrow-gauge, small manus ichnogenus Parabrontopodus, and one large trackway is characterised by a wide-gauge and large manus, similar to Brontopodus. This suggests the co-occurrence of two different sauropod groups. A further component in these ichnoassemblages is a tetradactyl morphotype and trackways of ornithischian affinity that are tentatively attributed to psittacosaurs.
Article
Globally, skeletal remains of dinosaurs are particularly rare throughout much of the Middle Jurassic. Thus, other sources of evidence, and most importantly ichnofaunas, are important indicators of the contemporary terrestrial vertebrate communities. The outcrops of the Ravenscar Group (Aalenian—Bajocian) within the Cleveland Basin of Yorkshire, UK, which have recently been recognised as a megatracksite of global significance, provide one such major source of ichnofaunal information of this age. A comprehensive database on the variety and occurrence of dinosaur and other vertebrate traces within the Ravenscar Group has been built from a long-term and detailed study of the sequence. Thirty different and distinct morphotypes of vertebrate traces have been recognised and are being analysed and further differentiated morphometrically. Some of the morphotypes represent behavioural, preservational and perhaps ontogenetic variants of other morphotypes, but nevertheless the range of quadrupedal and bipedal prints allows an overall fauna of sauropod, stegosaurian, ornithopod and theropod dinosaurs along with crocodiles, pond turtles and fish to be reconstructed. The distribution and abundance of prints and print types within the succession shows evidence of environmental control on the behaviour and distribution of the vertebrates. Case studies highlight both the advantages and disadvantages of this type of data in reconstructing palaeocommunities.
Article
Three-dimensional, dynamic, computer models of the pelvis and hind limbs of theropods and ornithopods are used to produce synthetic trackways using a range of gait angles and degrees of limb joint flexion. The hip heights of the modeled stances are compared with the predictions of hip heights computed with various formulae that incorporate parameters measured from footprints and trackways. The tested formulae include: 4*footprint-length and other morphometric methods where the coefficients vary according to the size and taxonomic group of the inferred trackmaker, allometric methods with size and taxon specific coefficients and exponents, and pace-length divided by 0.6. The best fit (least difference) between model and predicted hip heights is achieved with the simple 4*footprint-length formula. The pace-length formula also works well, but only for a very narrow gait range. With one exception, a small theropod, the variable morphometric and allometric formulae consistently overestimate the hip heights in all case. For large theropods and ornithopods the overestimates can be up to 84% in extreme cases. There was also a trend for the magnitudes of overestimation to increase with increasing size of the trackmaker. The overestimates of hip height using these methods results in underestimation of the computed velocities attributed to the dinosaurs that made the trackways.