Muyelensaurus pecheni gen. et sp.nov., stereophotographs of the posterior dorsal vertebra (MRS-Pv 412) in anterior view. Scale bar = 5cm.  

Muyelensaurus pecheni gen. et sp.nov., stereophotographs of the posterior dorsal vertebra (MRS-Pv 412) in anterior view. Scale bar = 5cm.  

Source publication
Article
Full-text available
The discovery of Muyelensaurus pecheni gen. et sp.nov., a new slender titanosaurid, is relevant from anatomical and systematic viewpoints. The specimens come from the Upper Cretaceous strata of the Portezuelo Formation (Turonian-Early Coniacian) at Loma del Lindero, Rincón de los Sauces area, Neuquén Province, Argentina. The remains include a brain...

Context in source publication

Context 1
... prespinal lamina is large anteroposteriorly and reaches the base of the neural arch. There are two small accessory prespinal laminae bifurcated close to the base of the neural arch (Fig.7). This character has not been described in any other posterior dorsal vertebrae of titanosaurs and is considered herein as a probable autapomorphy of Muyelensaurus. ...

Similar publications

Article
Full-text available
Argentinosaurus (Cenomanian, Argentina) is generally accepted as being the largest dinosaur so far discovered and is one of several giant titanosaurian sauropods known from the Upper Cretaceous of South America and Asia, but surprisingly not from North America. Here we present the first evidence of giant titanosaurian sauropods from the Upper Creta...

Citations

... Mendozasaurus neguyelap was discovered in the middle-upper Coniacian Sierra Barrosa Formation, in Mendoza Province (González Riga , 2005. The anatomy of this taxon has been extensively studied (González , helping to define two new titanosaurian clades: Lognkosauria (Calvo et al. 2007a) and Colossosauria (González . Approximately 200 bones and bone fragments, which represent four individuals, were recovered from the Arroyo Seco site. ...
Chapter
Most taphonomy studies of South American sauropodomorphs have addressed extrinsic factors such as sedimentary environments, bone dispersal, and mineralogical processes that occurred during fossil diagenesis. These studies provide important data on the taphonomic modes which are associated with bone accumulations in different paleoenvironmental contexts. However, these analyses have generally not considered intrinsic factors like the shape, size, and structural integrity of the skeletal elements, variables that can produce some taphonomic bias. Sauropodomorphs include dinosaurs of highly varied sizes, ranging from small (less than 8 m long) to remarkably giant forms (around 30 m long). In the largest sauropods, such as the huge titanosaurs, very incomplete skeletons are commonly found and most notably skull and articulated pedes rarely are preserved. We focus here on some intrinsic anatomical factors as they relate to articulation in some key parts of the skeletons. Further, this study suggests that the preservation of fragile portions of sauropodomorph skeletons was possible only under specific combinations of sedimentological and biological processes.
... The colossal Futalognkosaurus dukei (Calvo et al. 2007a), represented by a partially articulated skeleton, was described two years later from Los Barreales lake, in Central Neuquén Province, recognizing for the first time a clade of giant titanosaurs named Lognkosauria. At the same time, another slender smallsized titanosaur was described as Muyelensaurus pecheni (Calvo et al. 2007b), from The last decade showed an exponential increase in the record of BST, with fourteen new taxa nominated. Four new taxa were described in 2011. ...
... The discovery of Notocolossus has been important to analyze in detail the progressive reduction in the number of phalanges along the line to derived titanosaurs, resulting in the more reduced phalangeal formula of all sauropods. Rinconsauria Calvo, González Riga, and Porfiri 2007b Definition A node-based clade is defined as Muyelensaurus pecheni Calvo et al. 2007a, b, Rinconsaurus caudamirus Calvo and, their most common ancestor, and all of its descendants (Calvo et al. 2007b). ...
... The analysis of Carballido et al. (2017) Rinconsauria clade was erected by Calvo, González Riga, and Porfiri (2007b) when Muyelensaurus was described in 2007. This is a node-based clade defined as 'Muyelensaurus pecheni, Rinconsaurus caudamirus, their most recent common ancestor, and all its descendants'. ...
Chapter
Titanosaurian sauropods were the most diverse and successful group of large-bodied terrestrial herbivores. Two aspects regarding their evolutionary history stand out, namely their great morphological diversity and their extensive record from various continental masses. In South America, and particularly in Argentina, the group has the richest record worldwide. This is mainly due to the conjunction of two factors: the extensive paleontological investigation carried out by South American researchers since the beginning of the twentieth century and the well-exposed outcrops of Cretaceous continental strata. With the exception of Tapuiasaurus from Brazil, the entire record of South American named titanosaurs discovered in the Berriasian–Santonian interval comes from Argentina, specifically from Patagonia, including the south of Mendoza, Neuquén, Río Negro, and Chubut Provinces. With a number of 22 valid taxa, the Early and ‘Mid’-Cretaceous titanosaur record of South America includes basally branching (‘basal’) forms (e.g., Andesaurus, Ninjatitan), basal and derived lithostrotians (e.g., Sarmientosaurus, Tapuiasaurus, and Epachthosaurus), and most of the colossosaurs (mainly the giant lognkosaurs Mendozasaurus, Futalognkosaurus, Patagotitan, and Notocolossus). After their origin in the Early Cretaceous, titanosaurians experienced a rapid increase in taxonomic diversity, which is maintained toward the Late Cretaceous. However, during the Berriasian–Santonian interval, the size of titanosaurs reached its climax, representing the largest vertebrate animals ever to inhabit the earth. Some South American titanosaurs from this time have been widely used to define new clades (e.g., Colossosauria, Lognkosauria, Rinconsauria) that clarified the main phylogenetic relationships at lower level. Moreover, studies in some key paleobiological aspects related with the estimation of size contributed to better understanding the biology of some species in the context of the process of gigantism.
... Muyelensaurus pecheni: 0.29(Calvo, González-Riga & Porfiri, 2007a); Elaltitan lilloi: 0.30(Mannion & Otero, 2012); Dr. schrani: 0.34(Ullmann & Lacovara, 2016); Patagotitan mayorum: 0.38(Carballido et al., 2017); Saltasaurus loricatus: 0.4 (González Riga et al., 2019); W. wattsi: 0.42 (Hocknull et al., 2009; Poropat et al., 2015a); Jiangshanosaurus lixianensis: 0.42 (Mannion et al., 2019a); Scapulae of Australotitan cooperensis gen. et sp. ...
Article
Full-text available
A new giant sauropod, Australotitan cooperensis gen. et sp. nov., represents the first record of dinosaurs from the southern-central Winton Formation of the Eromanga Basin, Australia. We estimate the type locality to be 270–300 m from the base of the Winton Formation and compare this to the semi-contemporaneous sauropod taxa, Diamantinasaurus matildae Hocknull et al., 2009, Wintonotitan wattsi Hocknull et al., 2009 and Savannasaurus elliottorum Poropat et al., 2016. The new titanosaurian is the largest dinosaur from Australia as represented by osteological remains and based on limb-size comparisons it reached a size similar to that of the giant titanosaurians from South America. Using 3-D surface scan models we compare features of the appendicular skeleton that differentiate Australotitan cooperensis gen. et sp. nov. as a new taxon. A key limitation to the study of sauropods is the inability to easily and directly compare specimens. Therefore, 3-D cybertypes have become a more standard way to undertake direct comparative assessments. Uncoloured, low resolution, and uncharacterized 3-D surface models can lead to misinterpretations, in particular identification of pre-, syn- and post-depositional distortion. We propose a method for identifying, documenting and illustrating these distortions directly onto the 3-D geometric surface of the models using a colour reference scheme. This new method is repeatable for researchers when observing and documenting specimens including taphonomic alterations and geometric differences. A detailed comparative and preliminary computational phylogenetic assessment supports a shared ancestry for all four Winton Formation taxa, albeit with limited statistical support. Palaeobiogeographical interpretations from these resultant phylogenetic hypotheses remain equivocal due to contrary Asian and South American relationships with the Australian taxa. Temporal and palaeoenvironmental differences between the northern and southern-central sauropod locations are considered to explain the taxonomic and morphological diversity of sauropods from the Winton Formation. Interpretations for this diversity are explored, including an eco-morphocline and/or chronocline across newly developed terrestrial environments as the basin fills.
... This posterior process is almost complete, and an examination of the bone indicates that only a fragment of 1 cm Figure 41; FMNH PR 2209) but in these cases, the posterior process is anteroposteriorly broader. It contrasts dramatically with the ischia of Aeolosaurus maximus (Santucci and De Arruda-Campos, 2011), Aeolosaurus rionegrinus (Powell, 1987), Gondwanatitan faustoi (Kellner and Acevedo, 1999), Rinconsaurus caudamirus , Sonidosaurus saihangaobiensis (Xu et al., 2006), and Muyelensaurus pecheni (Calvo et al., 2007b) that have a relative long posterior process. The relative size of the posterior process can be measured following Salgado et al. (1997), using the ratio between the pubic peduncle and the distance from the upper corner of the pubic plate up to the distal end of the posterior process. ...
... Within Colossosauria, we recovered Lognkosauria (sensu Calvo et al., 2007a), Rinconsauria (sensu Calvo et al., 2007b) and Aeolosaurini (after new phylogenetic definition of Carballido et al., 2017). A recent study places Aeolosaurini nested in Rinconsauria (Hechenleitner et al., 2020), as a least inclusive group of dinosaurs closely related to Aeolosaurus. ...
Article
A new lithostrotian sauropod, Arackar licanantay gen. et sp. nov. is described based on a partial skeleton from the Upper Cretaceous (CampanianeMaastrichtian) beds of the Hornitos Formation, Atacama Region, northern Chile. The holotype consists of axial (cervical and dorsal vertebrae) and appendicular (humerus, femur and ischium) elements of a sub-adult specimen (ca. 6.3 m long). Autapomorphies characterizing this new titanosaur include: middle neural arches with wide and tall centroprezygapophyseal fossa þ parapophyseal centroprezygapophyseal fossa (cprf þ pacprf) extending on the entire anterior faces of the pedicles, but not above the neural canal, and reduced spinopostzygapophyseal laminae, shorter than the postzygapophyseal facet length. A phylogenetic analysis based on a data matrix of 87 taxa and 405 characters recovered Arackar as a derived lithostrotian titanosaur, placing it in a clade that includes Rapetosaurus þ (Arackar þ Isisaurus). This is the third dinosaur named from Chile and the third titanosaur from the western side of the Andes in South America.
... obs., 2014)] in which the posterior surface of the supraoccipital is smooth, lacking any distinct midline ridge. Diamantinasaurus also lacks the midline groove that extends along the supraoccipital of Muyelensaurus (Calvo et al., 2007a), Bonatitan (Martinelli & Forasiepi, 2004;Salgado et al., 2015a), Saltasaurus (Powell, 1992(Powell, , 2003, Rapetosaurus (Curry Rogers & Forster, 2004) and an indeterminate titanosaur specimen from the latest Cretaceous of Argentina (García et al., 2008). The anterior end of the nuchal crest preserves a dorsally tapered, triangular opening that was probably overlapped by the paired parietals anteriorly. ...
... The foramen magnum is taller dorsoventrally (42 mm) than it is wide transversely (36 mm), as in many, but not all, macronarians (Martínez et al., 2016). Among titanosaurs, the foramen magnum is taller than wide in Sarmientosaurus (Martínez et al., 2016), Pitekunsaurus (Filippi & Garrido, 2008), Antarctosaurus (Powell, 2003), Bonatitan (Martinelli & Forasiepi, 2004;Salgado et al., 2015a), Quaesitosaurus and Nemegtosaurus (Wilson, 2005), Jainosaurus and Vahiny Curry Rogers & Wilson, 2014; by contrast, the foramen magnum is subcircular in Malawisaurus (Gomani, 2005), Kaijutitan (Filippi et al., 2019), Narambuenatitan (Filippi et al., 2011), Muyelensaurus (Calvo et al., 2007a), Saltasaurus (Powell, 1992(Powell, , 2003, Rapetosaurus (Curry Rogers & Forster, 2004) and MPCM-HUE-8741 (Knoll et al., 2013). Each ventrolateral margin of the foramen magnum bears a small opening that communicates with another opening at the base (medial) of the paroccipital processes; this represents the passage of CN XII (hypoglossal). ...
... Among titanosaurs, most taxa have a comparable or even greater ratio (Mannion, 2011: table 1), but this ratio is < 1.5 in Nemegtosaurus (Wilson, 2005) and Rapetosaurus (Curry Rogers & Forster, 2004). The basal tubera are divergent from each other only at their ventral ends, with an angle of ~40° (based on the preserved portion of the left one); this distinguishes Diamantinasaurus from most titanosauriforms, in which this angle of divergence is > 50° (Curry Rogers, 2005;Calvo et al., 2007a;Poropat et al., 2016). Sarmientosaurus (Martínez et al., 2016), Quaesitosaurus (Curry Rogers & Wilson, 2014: fig. ...
Article
The titanosaurian sauropod dinosaur Diamantinasaurus matildae is represented by two individuals from the Cenomanian-lower Turonian 'upper' Winton Formation of central Queensland, northeastern Australia. The type specimen has been described in detail, whereas the referred specimen, which includes several elements not present in the type series (partial skull, atlas, axis and postaxial cervical vertebrae), has only been described briefly. Herein, we provide a comprehensive description of this referred specimen, including a thorough assessment of the external and internal anatomy of the braincase, and identify several new autapomorphies of D. matildae. Via an expanded data matrix consisting of 125 taxa scored for 552 characters, we recover a close, well-supported relationship between Diamantinasaurus and its contemporary, Savannasaurus elliottorum. Unlike previous iterations of this data matrix, under a parsimony framework we consistently recover Diamantinasaurus and Savannasaurus as early-diverging members of Titanosauria using both equal weighting and extended implied weighting, with the overall topology largely consistent between analyses. We erect a new clade, named Diamantinasauria herein, that also includes the contemporaneous Sarmientosaurus musacchioi from southern Argentina, which shares several cranial features with the referred Diamantinasaurus specimen. Thus, Diamantinasauria is represented in the mid-Cretaceous of both South America and Australia, supporting the hypothesis that some titanosaurians, in addition to megaraptoran theropods and possibly some ornithopods, were able to disperse between these two continents via Antarctica. Conversely, there is no evidence for rebbachisaurids in Australia, which might indicate that they were unable to expand into high latitudes before their extinction in the Cenomanian-Turonian. Likewise, there is no evidence for titanosaurs with procoelous caudal vertebrae in the mid-Cretaceous Australian record, despite scarce but compelling evidence for their presence in both Antarctica and New Zealand during the Campanian-Maastrichtian. These later titanosaurs presumably dispersed into these landmasses from South America before the Campanian (~85 Mya), when seafloor spreading between Zealandia and Australia commenced. Although Australian mid-Cretaceous dinosaur faunas appear to be cosmopolitan at higher taxonomic levels, closer affinities with South America at finer scales are becoming better supported for sauropods, theropods and ornithopods.
... This clade is recognized on the strict consensus tree of the second analysis but on the strict consensus tree of the first analysis some rinconsaurs ae collapsed in a polytomy with Epachthosaurus (Fig. 4). Rinconsauria is a node based clade stemming on Muyelensaurus and Rinconsaurus (Calvo et al., 2007). Among rinconsaurs, the anterior caudals, compatible in position with BM 38/7120, are not known for Rinconsaurus caudamiris Calvo and Gonz alez Riga, 2003 from the TuronianeConiacian Río Neuqu en Formation of Argentina (Calvo and Gonz alez Riga, 2003). ...
Preprint
An additional anterior caudal vertebra of a titanosaurian sauropod Tengrisaurus starkovi from the Lower Cretaceous (Barremian–Aptian) Murtoi Formation of Transbaikalia, Asiatic Russia, reveals new morphological details of this taxon. The new characters include dorsoventrally compressed cotyle and condyle of the centrum and a prominent ridge separating the condyle from the rest of the centrum with the ventral triangular plate (autapomorphy). Parsimony phylogenetic analysis places Tengrisaurus in the predominantly Gondwanan clade Colossosauria + Epachthosaurus on the strict consensus tree and as the sister taxon to the Colossosauria on 66% of the most parsimonious trees. Among Colossosauria, Tengrisaurus is similar with Normanniasaurus from the Albian of France by having a dorsoventrally compressed condyle circumscribed by a distinct ridge, a distinct depression anteroventral to the postzygapophysis, and a deep depression within the postspinal fossa. This discovery suggests that ancestors of the clade Colossosauria were widely distributed in Eurasia during the Early Cretaceous and the clade becomes restricted to the southern continents in the Late Cretaceous.
... The nomenclature for vertebral laminae follows wilson (1999) with modifications (a. PCDL; Figs. 9 and 11) from Salgado et al. (2005) SAuRISCHIA Seeley, 1888 SAuROPODOMORPHA von Huene, 1932SAuROPODA Marsh, 1878 neOSAuROPODA Bonaparte, 1986 TITAnOSAuRIFORMeS TITAnOSAuRIA Bonaparte & Coria, 1993 RInCOnSAuRIA Calvo, González Riga, & Porfiri, 2007b Genus Rinconsaurus Calvo & González Riga, 2003 Type species. Rinconsaurus caudamirus Calvo & González Riga, 2003. ...
... These features are now also known to be widely distributed in several titanosaurs throughout the Coniacian-Maastrichtian. Posteriorly inclined neural spines are found in several taxa, including Rapetosaurus, Trigonosaurus, Overosaurus, Futalognkosaurus,and Epachthosaurus(Carballido et al., 2017;Gorscak & O'Connor, 2019;González Riga et al., 2019). The presence of postzygapophyseal process in middle caudal vertebrae has been reported in several titanosaurs including Muyelensaurus, Overosaurus, Bonitasaura, and Pitekunsaurus(Calvo et al., 2007b;Carballido et al., 2017;Coria et al., 2013;Gorscak & O'Connor, 2019;González Riga et al., 2019). Finally, the presence of amphicoelous-biconvex or amph-icoelous-opisthocoelous-biconvex centra is now known inPitekunsaurus(Filippi & Garrido, 2008) and opisthocoelous posterior caudal vertebrae are present in Muyelensaurus (MAu-PV-LL-175, APM pers. ...
Article
Full-text available
Titanosaurs were the predominant herbivores during the Late Cretaceous, inhabiting all continents. This clade was especially diverse in South America with some of the largest and smallest sauropod species known to date. Despite its diversity, the evolution of this clade is far from being well-known, although some recent analyses have begun to find some consensus in their results. Rinconsauria (defined as the least inclusive clade containing Rinconsaurus and Muyelensaurus) includes small titanosaurs and is considered as closely related to the lineage of giant titanosaurs, Lognkosauria (defined as the least inclusive clade containing Futalognkosaurus and Mendozasaurus), both being part of the recently named clade Colossosauria. The titanosaur Rinconsaurus caudamirus, from the Bajo de la Carpa Formation (Santonian), Río negro, Argentina, is represented by several axial and appendicular elements from at least four specimens. This taxon was only briefly described when it was named and most of its originally proposed autapomorphies are now recognized as having a more widespread distribution amongst titanosaurs. Herein we present a detailed osteological description of the axial skeleton and a revised diagnosis for this taxon that firmly establishes its validity. Based on comparisons with other titanosaurs, we found three new possible autapomorphies for the axial skeleton of Rinconsaurus, which added to its original combination of characters, endorsing this taxon as a valid genus. Besides, this revision of Rinconsaurus provides additional osteological data that will contribute to a better resolution of titanosaur phylogeny, contributing at the same time to our understanding of the clade Rinconsauria.
... Besides, some taxa recovered within Rinconsauria are often included within Aeolosaurini, a group of titanosaurians with unstable interspecific phylogenetic relationships 12 . Our results suggest that Rinconsauria is much more diverse and widely distributed than previously thought 2,3,6,9,37 . The oldest representatives of this clade would be in northern Patagonia, for the earliest Late Cretaceous. ...
Article
Full-text available
South American titanosaurians have been central to the study of the evolution of Cretaceous sauropod dinosaurs. Despite their remarkable diversity, the fragmentary condition of several taxa and the scarcity of records outside Patagonia and southwestern Brazil have hindered the study of continental-scale paleobiogeographic relationships. We describe two new Late Cretaceous titanosaurians from Quebrada de Santo Domingo (La Rioja, Argentina), which help to fill a gap between these main areas of the continent. Our phylogenetic analysis recovers both new species, and several Brazilian taxa, within Rinconsauria. The data suggest that, towards the end of the Cretaceous, this clade spread throughout southern South America. At the same locality, we discovered numerous accumulations of titanosaurian eggs, likely related to the new taxa. With eggs distributed in three levels along three kilometres, the new site is one of the largest ever found and provides further evidence of nesting site philopatry among Titanosauria.
... Some other dinosaur clades, in turn, do not belong to a 'family group' taxon at all, nor do they possess 'family group' names, such as, among others, Elasmaria (Calvo et al., 2007a; although the clade has been reconstructed to belong to the Thescelosaurinae; Boyd, 2015), Lognkosauria (Calvo et al., 2007b; originally a sub-clade of the Titanosauridae), Rinconsauria (Calvo et al., 2007c; originally a sister taxon to Aeolosaurini and a sub-clade of the Titanosauridae) and Turiasauria (Royo-Torres et al., 2006). ...
Article
Full-text available
Ornithopod dinosaurs were abundant inhabitants of European islands during the Late Cretaceous. The long history of dinosaur research in Europe has led to the establishment of new taxa for numerous ornithopod specimens that received considerable attention in the literature; however, many of these remain essentially unstudied. This explains why little is known of their potential phylogenetic, ecological and biogeographical importance. Here we provide a reassessment of Orthomerus dolloi, an enigmatic ornithopod taxon that was established on the basis of isolated appendicular elements, including a left tibia, a right femur, a left femur and a metatarsal. The material originates from the uppermost Maastrichtian of southern Limburg (the Netherlands) or adjacent Belgian territory. Despite the fact that they have been known for almost 140 years, none of these elements has been evaluated in detail since their original description. Here we redescribe and illustrate the syntypes of O. dolloi, and compare them to corresponding elements in other latest Cretaceous ornithopods from Europe. The character distribution in O. dolloi is further explored by means of phylogenetic analyses, using a revised ornithopod-wide dataset. The material belongs to at least two, probably conspecific, individuals that show clear hadrosauroid affinities, although the exact placement of the taxon within the clade remains contentious, because it is likely that its elements are osteologically immature. Therefore, the common assignment of O. dolloi to hadrosaurid ornithopods is questionable. Nevertheless, our revision of the material has not identified any autapomorphies, nor a combination of characters that would be indisputably unique among Hadrosauroidea.
... In LMCCE 005/120 and LMCCE 007/25 the neural arch is relatively low and occupies more than half of the centrum length. This contrast the condition of derived Gondwanan titanosaurs, where the middle caudals often have tall neural arch occupying half or less of the centrum length (Calvo et al., 2007;Curry Rogers, 2009;Carballido et al., 2011;Filippi et al., 2011). ...
... The second interpretation seems more plausible taking into account a large temporal and geographic gap between the Early Cretaceous Siberian taxon and the Late Cretaceous South American Saltasaurinae. The Saltasaurinae includes Saltasaurus, Neuquensaurus, and Rocasaurus (Salgado et al., 1997;Curry Rogers, 2005;Bonaparte et al., 2006;Calvo et al., 2007;Bandeira et al., 2016) and only one taxon (Neuquensaurus) approaches the condition of the neural spine of middle caudal vertebrae seen in LMCCE 005/40. ...
Article
Three sauropod middle caudal vertebrae are described from the three different localities within the Lower Cretaceous (Barremian-Aptian) Ilek Formation in Krasnoyarsk Territory, Western Siberia, Russia. All vertebrae are strongly procoelous and can be referred to Lithostrotia indet. LMCCE 005/40 from Bol'shoi Kemchug 3 locality has a ventral groove on centrum and a very large neural spine that projects posteriorly far beyond the centrum. This specimen also lacks postzygapophyses and bears a heavily sculptured neural spine suggesting high degree of development of the interosseous ligaments. The structure of the neural spine LMCCE 005/40 is similar to that of the saltasaurine Neuquensaurus from the Late Cretaceous of South America. However, the Siberian specimen lacks camellate bone texture characteristic for the caudal vertebrae of Saltasaurinae and its similarity with Neuquensaurus in development of the neural spine likely was independently acquired. These new findings increase the known diversity of sauropod dinosaurs in the Early Cretaceous of Siberia, which includes three taxa of Lithostrotia indet. described herein, lithostrotian Tengrisaurus, and titanosauriform Sibirotitan.