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Elements of the holotypic material of Chebsaurus algeriensis. (a) D001-63 basioccipital in caudal view; (b) D001-77 right surangular in lateral view; (c) D001-78 tooth in lingual view, with an enlargement of the root surface texture; (d) D001-32 right ulna in medial view; (e) D001-08 ungual phalanx in lateral view; (f) D001-49 carpal bone; (g) D001-02 pedal phalanx in palmar view; (h) D001-01 manual phalanx in dorsal view; (i) D001-36 proximal end of right pubis in proximal view; (j) D001-15 cranial portion of cervical centrum in left lateral view; (k) D001-35 dorsal neural spine in left lateral view; (l) D001-17 dorsal centrum in left lateral view; (m) D001-20 caudal centrum in left lateral view. Scale bars are 3 cm for all, except (c): 2 cm. Abbreviations: BoT., Basioccipital tubera; b. podl., base of the postzygodiapophysial lamina; e. fossa, elliptic fossa; for., foramen; pl., pleurocoel. Éléments de l'holotype de Chebsaurus algeriensis. (a) D001-63 basioccipital en vue caudale ; (b) D001-77 surangulaire droit en vue latérale ; (c) D001-78 dent en vue linguale, avec un agrandissement de la texture de la surface de la racine ; (d) D001-32 ulna droite en vue médiale ; (e) D001-08 phalange unguéale en vue latérale ; (f) D001-49 os carpien ; (g) D001-02 phalange du pied en vue palmaire ; (h) D001-01 phalange de la main en vue dorsale ; (i) D001-36 extrémité proximale du pubis droit en vue proximale ; (j) D001-15 fragment cranial de centrum de vertèbre cervicale en vue latérale gauche ; (k) D001-35 épine neurale de vertèbre dorsale en vue latérale gauche ; (l) D00117 centrum de vertèbre dorsale en vue latérale gauche ; (m) D001-20 centrum de vertèbre caudale en vue latérale gauche. Barres d'échelle : 3 cm, à part (c) : 2 cm. Abréviations : BoT., tubercules basioccipitaux ; b. podl., base de la lame postzygo-diapophysiale ; e. fossa, fosse elliptique ; for., foramen ; pl., pleurocoele.

Elements of the holotypic material of Chebsaurus algeriensis. (a) D001-63 basioccipital in caudal view; (b) D001-77 right surangular in lateral view; (c) D001-78 tooth in lingual view, with an enlargement of the root surface texture; (d) D001-32 right ulna in medial view; (e) D001-08 ungual phalanx in lateral view; (f) D001-49 carpal bone; (g) D001-02 pedal phalanx in palmar view; (h) D001-01 manual phalanx in dorsal view; (i) D001-36 proximal end of right pubis in proximal view; (j) D001-15 cranial portion of cervical centrum in left lateral view; (k) D001-35 dorsal neural spine in left lateral view; (l) D001-17 dorsal centrum in left lateral view; (m) D001-20 caudal centrum in left lateral view. Scale bars are 3 cm for all, except (c): 2 cm. Abbreviations: BoT., Basioccipital tubera; b. podl., base of the postzygodiapophysial lamina; e. fossa, elliptic fossa; for., foramen; pl., pleurocoel. Éléments de l'holotype de Chebsaurus algeriensis. (a) D001-63 basioccipital en vue caudale ; (b) D001-77 surangulaire droit en vue latérale ; (c) D001-78 dent en vue linguale, avec un agrandissement de la texture de la surface de la racine ; (d) D001-32 ulna droite en vue médiale ; (e) D001-08 phalange unguéale en vue latérale ; (f) D001-49 os carpien ; (g) D001-02 phalange du pied en vue palmaire ; (h) D001-01 phalange de la main en vue dorsale ; (i) D001-36 extrémité proximale du pubis droit en vue proximale ; (j) D001-15 fragment cranial de centrum de vertèbre cervicale en vue latérale gauche ; (k) D001-35 épine neurale de vertèbre dorsale en vue latérale gauche ; (l) D00117 centrum de vertèbre dorsale en vue latérale gauche ; (m) D001-20 centrum de vertèbre caudale en vue latérale gauche. Barres d'échelle : 3 cm, à part (c) : 2 cm. Abréviations : BoT., tubercules basioccipitaux ; b. podl., base de la lame postzygo-diapophysiale ; e. fossa, fosse elliptique ; for., foramen ; pl., pleurocoele.

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Continental strata of Early and Middle Jurassic age are seldom-exposed, and little is known of the history of sauropod dinosaurs prior to the neosauropod radiation of the end of the Middle Jurassic. Here, we report, in the Middle Jurassic of the Occidental Saharan Atlas (Algerian High Atlas), the discovery of a skeleton, including cranial material,...

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... D001-01 à 78 ( Fig. 2), temporairement conservé au CRD de Sonatrach, Boumerdès, Algérie ; squelette partiel d'un sauropode juvénile, comprenant du matériel crânien, qui inclut un surangulaire, un frag- ment de basioccipital et des ...
Context 2
... D001-01 to 78 ( Fig. 2), temporarily in Sonatrach CRD, Boumerdès, Algeria; partial skeleton and cranial material of a juvenile sauropod including a part of basioccipital, a surangular and ...
Context 3
... is not a neosauropod because the dorsal surfaces of the cervical parapophyses are excavated and they are not separated from the lateral excavation by a ridge podl., base of the postzygodiapophysial lamina; e. fossa, elliptic fossa; for., foramen; pl., pleurocoel. Fig. 2. Éléments de l'holotype de Chebsaurus algeriensis. (a) D001-63 basioccipital en vue caudale ; (b) D001-77 surangulaire droit en vue latérale ; (c) D001-78 dent en vue linguale, avec un agrandissement de la texture de la surface de la racine ; (d) D001-32 ulna droite en vue médiale ; (e) D001-08 phalange unguéale en vue latérale ; (f) ...

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... observ., 2010). The dorsal surface of the parapophysis is excavated in Hudiesaurus, and this depression is continuous with the lateral pneumatic opening, as seen in the cervical vertebrae of many non-neosauropod eusauropods, such as Cetiosaurus and Chebsaurus Martin, 2002, 2003;Upchurch et al., 2004a;Mahammed et al., 2005). Many neosauropods also have dorsally excavated cervical parapophyses, but such taxa typically possess a ridge that divides this depression from the lateral pneumatic opening (Upchurch, 1998;Martin, 2002, 2003). ...
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Hudiesaurus sinojapanorum is a Late Jurassic sauropod from northwestern China that was erected on the basis of a cervicodorsal vertebra, four teeth, and a nearly complete forelimb. However, re-evaluation of this material, and comparisons with other taxa, indicate that there are few grounds for regarding these specimens as congeneric. Consequently, although we retain the vertebra as the holotype specimen of Hudiesaurus, the forelimb is assigned to a new taxon—Rhomaleopakhus turpanensis, gen. et sp. nov. The teeth previously referred to Hudiesaurus are poorly preserved but resemble those of several other ‘core Mamenchisaurus-like taxa’ (CMTs) from East Asia, such as Mamenchisaurus sinocanadorum. Phylogenetic analyses confirm that Hudiesaurus is a CMT and the sister taxon of Xinjiangtitan. Despite some uniquely shared features, their large size, and close geographic provenance, Hudiesaurus and Xinjiangtitan are retained as distinct genera based on their stratigraphic separation and numerous anatomical differences. Rhomaleopakhus is also shown to be a CMT in all analyses, being most closely related to Chuanjiesaurus and Analong. We link the convergent evolution of robust antebrachia and an enlarged olecranon in CMTs, titanosaurs, and some ornithischians (e.g., ceratopsids) to a more flexed orientation of the forearm, an enhanced role for the forelimb in locomotion, and an anterior shift in the whole-body center of mass. CMTs and titanosaurs potentially converged on a feeding strategy in which the ability to increase browse height via bipedal rearing was sacrificed in return for more efficient locomotion that improved travel between patchily distributed food sources.
... A similar peculiar enamel wrinkling pattern is seen in two teeth from the Kem Kem beds of Morocco and Algeria, described in Holwerda et al. (2018) as being possibly derived from rebbachisaurids. A brachiosaurid was also reported from Rouis El Djir, Algeria, by Lapparent (1960), and by Taquet (2010); however, this has more recently been found to be Jurassic, and the material belongs to a non-neosauropodan eusauropod, Chebsaurus (Läng and Mahammed, 2010;Mahammed et al., 2005). Rebbachisaurids, together with titanosauriforms, have been confirmed from postcranial elements as well by Mannion and Barrett (2013), who assigned a caudal vertebra to Rebbachisauridae, and diagnosed a partial dorsal vertebra as belonging to a somphospondylian titanosauriform. ...
... Bellusaurus sui from the Callovian-Oxfordian Shishugou Formation of Xinjiang Uyghur Autonomous Region, China is a basal macronarian or close relative of Neosauropoda (Dong 1990;Moore et al. 2018). Non-neosauropod eusauropods are also known from the Middle Jurassic of North Africa (Monbaron et al. 1999;Mahammed et al. 2005;Läng and Mahammed 2010). In the Middle Jurassic of Europe there are non-neosauropod eusauropods as well some putative neosauropods. ...
... A similar peculiar enamel wrinkling pattern is seen in two teeth from the Kem Kem beds of Morocco and Algeria, described in Holwerda et al. (2018) as being possibly derived from rebbachisaurids. A brachiosaurid was also reported from Rouis El Djir, Algeria, by Lapparent (1960), and by Taquet (2010); however, this has more recently been found to be Jurassic, and the material belongs to a non-neosauropodan eusauropod, Chebsaurus (Läng and Mahammed, 2010;Mahammed et al., 2005). Rebbachisaurids, together with titanosauriforms, have been confirmed from postcranial elements as well by Mannion and Barrett (2013), who assigned a caudal vertebra to Rebbachisauridae, and diagnosed a partial dorsal vertebra as belonging to a somphospondylian titanosauriform. ...
... The Bajocian of Australia has a few fragmentary bones of theropod and sauropod (Long et al. 1998). Morocco and Algeria have had several sauropods described from the Middle Jurassic rocks there (Montbarron et al. 1999, Mahammed et al. 2005. In Madagascar, sauropods and teeth of theropods of Middle Jurassic age have been found in the Isalo III Formation (Buffetaut 2005). ...
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A single footprint of a dinosaur was first found in the Middle Jurassic sediment on the Isle of Skye, Scotland in 1982 (Andrews & Hudson 1984, Delair & Sarjeant 1985). It took another ten years before any further discoveries were made. A small theropod tibia was found in Pliensbachian (Lower Jurassic) rocks in the Strathaird Peninsula in the south of the Isle of Skye (Benton et al. 1995), and a larger sauropod limb bone in rocks of BajocianBathonian (Middle Jurassic) in the Trotternish Peninsula of northern Isle of Skye (Clark et al. 1995)
... Sauropod tracks have also been described from the El Mers Formation (Jenny et al. 1981). Chebsaurus algeriensis is a non-neosauro pod eusauropod from the late Middle Jurassic (Callovian) Aïssa Formation of the Western Saharan Atlas, Algeria, and is represented by two partial juvenile skeletons, including cranial material (Mahammed et al. 2005;Läng and Mahammed 2010). ...
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Despite being globally widespread and abundant throughout much of the Mesozoic, the early record of sauropod dinosaur evolution is extremely poor. As such, any new remains can provide significant additions to our understanding of this important radiation. Here, we describe two sauropod middle cervical vertebrae from a new Early Jurassic locality in the Haute Moulouya Basin, Central High Atlas of Morocco. The possession of opisthocoelous centra, a well-developed system of centrodiapophyseal laminae, and the higher elevation of the postzygapophyses relative to the prezygapophyses, all provide strong support for a placement within Sauropoda. Absence of pneumaticity indicates non-neosauropod affinities, and several other features, including a tubercle on the dorsal margin of the prezygapophyses and an anteriorly slanting neural spine, suggest close relationships with various basal eusauropods, such as the Middle Jurassic taxa Jobaria tiguidensis and Patagosaurus fariasi. Phylogenetic analyses also support a position close to the base of Eusauropoda. The vertebrae differ from the only other Early Jurassic African sauropod dinosaurs preserving overlapping remains (the Moroccan Tazoudasaurus naimi and South African Pulanesaura eocollum), as well as stratigraphically younger taxa, although we refrain from erecting a new taxon due to the limited nature of the material. These new specimens represent one of the earliest eusauropod taxa and are an important additional data point for elucidating the early evolution of the clade.
... The Bajocian of Australia has a few fragmentary bones of theropod and sauropod [25,26]. Morocco and Algeria have had several sauropods described from the Middle Jurassic rocks there [27,28]. In Madagascar, sauropods and teeth of theropods of Middle Jurassic age have been found in the Isalo III Formation [20,29]. ...
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Chapter
Keywords – Dinosaurs, Morocco, Mesozoic Abstract – Fossiliferous sites in Morocco have yielded remains that are of considerable importance to the study of dinosaur evolution and paleobiogeography. Many important sites are located in the Atlas mountains and the southeastern part of the country. Dinosaur remains found in Morocco are noteworthy both because of their often exquisite preservation and because they record a relatively high level of taxonomic diversity. At least three lineages of sauropods and an equal number of theropod lineages have been recorded and the named taxa include some of the largest predatory dinosaurs known. The first expeditions, carried out between 1925 and 1955 in the Jurassic of the Atlas mountains yielded important sauropod material, described as a new species of Cetiosaurus, but likely distinct from the latter genus. Another large sauropod, Rebbachisaurus garasbae, was described from Cretaceous outcrops of the Kem Kem region in the southeast of the country. While the anatomy of this genus remains poorly known, members of the Rebbachisauridae have been reported from South America, Europe and other parts of Africa, adding to our understanding of the morphology and evolutionary history of the group. In the 1960s and 1970s little research and fieldwork was carried out, but Dutuit described a new putative dinosaur, Azendohsaurus laaroussi, a taxon that is now thought to be an archosauromorph of uncertain affinities. After this period of decreased activity, geological and paleontological fieldwork in the Atlas region in the 1970s and 1980s revived research projects and provided important data on the evolution of sauropod dinosaurs in particular. The most important discovery of this time is that of the sauropod Atlasaurus imelakei. A detailed description of Atlasaurushas not been published to date, but preliminary observations suggest that it was closely related to brachiosaurids such as Brachiosaurusand Giraffatitan. Atlasauruspreceeded these taxa by at least 10 million years, adding to the importance of this sauropod, as this interval in sauropod evolution is poorly known and sampled. In the 1990s and 2000s, new research efforts in the Kem Kem region have yielded remains of several large theropods: Spinosaurus, Carcharodontosaurusand Deltadromeus. New reconstructions, including the first detailed one published for the giant allosauroid Carcharodontosaurus, confirm that these taxa are amongst the largest terrestrial predators known. Spinosaurus, a giant, semiaquatictheropod with 2 m tall dorsal spines, and first described from Egypt, is now known from several isolated specimens and a partial skeleton from the Kem Kem region. Deltadromeus, a theropod of uncertain affinities, is noteworthy for its very slender built. The poorly known Sigilmassasaurusis here considered to be a synonym of Spinosaurus. The Kem Kem sequence has also yielded remains of an abelisaurid that appears to be very similar to Rugops primusfrom Niger. Caution has to be taken when naming taxa based on the often highly incomplete material from the Kem Kem sequence, often isolated vertebrae and teeth. A recently named theropod, Kemkemia auditorei, is now thought to represent a crocodylomorph instead. Theropod remains appear to be particularly abundant in the Kem Kem sequence, with sauropods represented by less common fossils and ornithopods represented by ichnofossils only. Suggestions that the abundance of theropods could be a consequenceof time averaging or collecting biases are not supported by available evidence from field collecting and the distribution of taxa in other North African deposits. More recently, finds in the Early Jurassic of the High Atlas have further improved the fossil record of dinosaurs, in particular the discovery of the basal sauropod Tazoudasaurusnaimiand the possible abelisauroid Berberosaurus liassicus. Tazoudasaurusrepresents one of the oldest known sauropods and is now known from multiple individuals and several ontogenetic stages. The material sheds light on sauropod evolution during the late Early Jurassic, a poorly known interval due to a general lack of suitable continental deposits elsewhere. In its skull morphology, Tazoudasaurusbears similarities to the Chinese taxa Shunosaurusand Abrosaurus, but is most similar to the basal sauropod Vulcanodon. The contemporaneous theropod Berberosaurus is only known from relatively incomplete material;it may represent the oldest abelisauroid. Localities in the High Atlas and in the Kem Kem region are focal points of ongoing research projects. Isolated dinosaur specimens have also been reported from the Moroccan Cretaceous phosphate deposits. In addition to body fossils, the Moroccan Atlas has also yielded some of the most remarkable dinosaur ichnofossil sites known, and theropod, sauropod and stegosaur tracks have been described. A poorly known dinosaur track horizon has also been described from the Cretaceous Kem Kem sequence. It is likely that manymore discoveries will be made in Africa in the coming years, providing a larger context for the Moroccan discoveries. Because of their stratigraphic relevance and their diversity the Moroccan taxa are particularly important and the country will continue to play a crucial role in the study of African dinosaurs. It is likely that many of the recent dinosaur discoveries will soon be on display in Morocco, as several new research collections have been created and paleontological exhibits are in development.
... It also lacks the overlap facets that occur in the Skye tooth (Allain et al. 2004). The teeth of Chebsaurus have the rugose texture and are wrinkled with v-shaped occlusal wear and a spoon-shaped crown lacking the lingual basal bulge seen on the Skye tooth (Mahammed et al. 2005). Patagosaurus lacks prominent grooves on the labial side of the tooth that was identified as a synapomorphy of the eusauropods and Barapasaurus by Upchurch (1998), but has serrations (Rauhut 2003). ...
Article
The discovery of a sauropod tooth and a single sauropod footprint from the Valtos Formation supplements our knowledge of these dinosaurs from the Middle Jurassic of the Isle of Skye. Although the family cannot be determined from this single tooth, it is thought that it represents a primitive eusauropod and may belong to a similar sauropod to that previously described from limited isolated osteological evidence (caudal vertebra, damaged humerus and a rib). The characteristics that suggest this affinity include evidence of denticles on one edge of the tooth, wrinkling and granulation of the enamel, wear suggesting crown-to-crown occlusion, and the spatulate tooth shape. The single sauropod footprint is the oldest record of a sauropod footprint from the Middle Jurassic of Skye. Supplementary material: Surface models of the sauropod footprint from the Valtos Formation produced using Agisoft Photoscan software in obj, ply and stl formats are available at: https://doi.org/10.6084/m9.figshare.c.3435984
... [8][9][10][11][12]. Apart from the Chinese record, a few taxa are known from northern Africa [13][14][15][16], Madagascar [17,18] and Argentina [19][20][21][22][23][24][25][26]. ...
... Diplodocids are characterized by asymmetrical enamel wrinkling distribution, and Rebbachisaurids have extreme asymmetrical enamel distribution [75], which has not been found in other sauropods. In some cases characteristics of the enamel wrinkling pattern have been explicitly regarded as autapomorphic at the species level (e.g., Amygdalodon, [26]; Chebsaurus, [15]). In other cases, peculiarities on the enamel wrinkling patterns have been noted for several taxa, such as very low, rounded, occasionally anastomosing undulations along the length of the tooth for Alamosaurus [76], characteristic reticulate wrinkling in Euhelopus [69], and enamel that is finely wrinkled throughout the crown but arranged into coarser longitudinal ridges in Nemegtosaurus [73], although these features of the enamel wrinkling pattern have not been explicitly treated as autapomorphies. ...
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The early Middle Jurassic is regarded as the period when sauropods diversified and became major components of the terrestrial ecosystems. Not many sites yield sauropod material of this time; however, both cranial and postcranial material of eusauropods have been found in the Cañadón Asfalto Formation (latest Early Jurassic–early Middle Jurassic) in Central Patagonia (Argentina), which may help to shed light on the early evolution of eusauropods. These eusauropod remains include teeth associated with cranial and mandibular material as well as isolated teeth found at different localities. In this study, an assemblage of sauropod teeth from the Cañadón Asfalto Formation found in four different localities in the area of Cerro Condor (Chubut, Argentina) is used as a mean of assessing sauropod species diversity at these sites. By using dental enamel wrinkling, primarily based on the shape and orientation of grooves and crests of this wrinkling, we define and describe three different morphotypes. With the exception of one taxon, for which no cranial material is currently known, these morphotypes match the local eusauropod diversity as assessed based on postcranial material. Morphotype I is tentatively assigned to Patagosaurus, whereas morphotypes II and III correspond to new taxa, which are also distinguished by associated postcranial material. This study thus shows that enamel wrinkling can be used as a tool in assessing sauropod diversity.