Biomechanical comments about Triassic dinosaurs from Brazil

Triassic dinosaurs of Brazil are found in Santa Maria and Caturrita formations, Rio Grande do Sul state, Brazil. There are three species known from the Santa Maria Formation (Staurikosaurus pricei, Saturnalia tupiniquim and Pampadromaeus barberenai), and two from Caturrita Formation (Guaibasaurus candelariensis and Unaysaurus tolentinoi). These dinosaur materials are, for the most part, well preserved and allow for descriptions of musculature and biomechanical studies. The lateral rotation of the Saturnalia femur is corroborated through calculations of muscle moment arms. The enhanced supracetabular crest of Saturnalia, Guaibasaurus, Staurikosaurus, Herrerasaurus ischigualastensis, Efraasia minor and Chormogisaurus novasi suggests that basal dinosaurs may have maintained an inclination of the trunk at least 20º on the horizontal axis. The pectoral girdle articulation of basal sauropodomorphs (Saturnalia and Unaysaurus) was established using a new method, the Clavicular Ring, and the scapular blade remains near 60º on the horizontal axis. This is a plesiomorphic condition among sauropodomorphs and is also seen in the articulated plateosauridae Seitaad ruessi. The Brazilian basal dinosaurs were lightweight with a body mass estimated around 18.5 kg for Staurikosaurus, 6.5 kg for Saturnalia, and 17 kg for Guaibasaurus. Pampadromaeus probably weighed 2.5 kg, but measures of its femur are necessary to confirm this hypothesis. The Triassic dinosaurs from Brazil were diversified but shared some functional aspects that were important in an evolutionary context.

Paleontological studies of Cretaceous vertebrate fossil beds in the Tataouine Basin (southern Tunisia)

The ‘Continental Intercalaire’ deposits of the Tataouine basin of southern Tunisia preserve one of the most diverse Cretaceous vertebrate fauna from Africa. This research project focuses on a detailed revision of the stratigraphic distribution of mid-Cretaceous fossil beds in the Tataouine Basin and includes the description of four, newly discovered vertebrate tracksites. In the Tataouine region, macro- and microvertebrate remains are recovered from three stratigraphic intervals: the lower Douiret Formation (Barremian), the Chenini (rare) and Oum ed Diab members of the Aïn El Guettar Formation (Albian). A detailed, basin-scale revision of the stratigraphic occurrence of fossil-bearing strata indicates 1. lateral facies variability within the context of a low gradient, circalittoral to coastal-plain environment; 2. multiple and diachronous fossil beds which include elasmobranchs, actinopterygians, sarcopterygians, turtles, crocodyliforms, pterosaurs, and non-avian dinosaurs remains. Four vertebrate tracksites have been discovered in the study area: 1. the Middle Jurassic Beni Ghedir site which preserves approximately 130 tridactyl footprints distributed over an area of 200 square meters, representing the oldest evidence of a dinosaur fauna in Tunisia; 2. the late Albian Chenini tracksite, which includes poorly preserved crocodilian tracks and the dinosaur ichnospecies Apulosauripus federicianus; 3. the Cenomanian Ksar Ayaat locality, where footprints assigned to a pleurodiran turtle are exposed, and 4. the upper Cenomanian Jebel Boulouha site which presents almost 100 well-preserved tridactyl tracks referred to small-sized theropods, fossil bird tracks - ichnogenus Koreanaorins – and tracks referred to a mammalian trackmaker, representing the first report of fossil bird and mammal from the Cretaceous of continental Africa and Tunisia respectively. In addition, data collected from the Tunisian tracksites have been compared with coeval tracksites in Italy and Croatia, showing analogies in morphology and paleoenvironment of dinosaur ichnoassociations, supporting the already hypothesized subaerial connection between these areas during the mid-Cretaceous.

Die Reproduktion von Dinosauriern, speziell der Sauropoden, und deren Bedeutung für ihren Gigantismus

Es wurde ein Teil der life-history, die Reproduktion, von Dinosauriern, speziell der Sauropoden, den größten bekannten jemals auf der Erde existierenden Landtieren, untersucht, um unter anderem den Zusammenhang zwischen Gigantismus und Reproduktion zu erforschen. Hierzu wurde eine mögliche life-history für Sauropoden, auf Grundlage des heutigen Forschungsstands in der Biologie und der Paläontologie, anhand einer Literaturrecherche erstellt. Des Weiteren wurde ein Modell zur Reproduktion bei ausgestorbenen oviparen Amnioten, basierend auf bestehenden Zusammenhängen zwischen Körpergröße und verschiedenen masse-spezifischen Reproduktionsmerkmalen (Eigewicht, Gelegegewicht, jähr. Gelegegewicht) bei rezenten oviparen Amnioten, erarbeitet. Mit Hilfe dieses Modells und Informationen aus Fossilfunden wurde der Frage nachgegangen, wie diese Reproduktionsmerkmale bei Dinosauriern wahrscheinlich ausgesehen haben. Weiterhin erfolgte die Überprüfung der Hypothese, dass Dinosaurier, insbesondere Sauropoden, eine höhere Reproduktionskapazität hatten als gleich große landlebende Säugetiere, was ersteren im Vergleich zu letzteren ermöglicht haben soll so viel größer zu werden (Janis und Carrano 1992). rnDie Untersuchungen der Zusammenhänge zwischen Körpergewicht und den masse-spezifischen Reproduktionsmerkmalen ergaben, dass das Körpergewicht immer stark mit den untersuchten Reproduktionsmerkmalen korreliert war. Große Vögel und große Reptilien unterscheiden sich in ihrem relativen Eigewicht (Eigewicht/Körpergewicht). Vögel haben relativ größere Eier. Betrachtet man das relative Gelegegewicht oder das relative jährliche Gelegegewicht so wird der Unterschied kleiner bzw. ist zwischen manchen Reptilien- und Vogelgruppen nicht mehr vorhanden. Dinosaurier hatten relative Eigewichte, die zwischen denen von Reptilien und Vögel liegen. Basale Dinosaurier, wie Prosauropoden, waren in ihrer Reproduktion eher reptilien-ähnlich, während vogel-ähnliche Theropoden eine Reproduktion hatten, die sich besser durch ein Vogelmodel beschreiben lässt. Die Reproduktion anderer Dinosaurier, wie Sauropoden und Hadrosaurier, lässt sich nicht eindeutig durch eines der beiden Modelle beschreiben und/oder die Modelle variierten in Abhängigkeit des betrachteten Merkmals. Trotzdem war es möglich für alle untersuchten Dinosaurier eine Abschätzung zur Gelegegröße und der Anzahl der jährlich gelegten Eier zu machen. Diese Schätzungen ergaben, dass die vermutete hohe Reproduktionskapazität von mehreren hundert Eiern pro Jahr nur für extrem große Sauropoden (70 t) haltbar ist. rnMit Ausnahme der Nagetiere fand ich die Unterschiede in der Reproduktionskapazität von Vögeln und Säugetieren, die Janis und Carrano (1992) postulierten, sogar auf der Ebene von Ordnungen. Dinosauriergelege waren größer als die Würfe von gleichgroßen (extrapolierten) Säugetieren während die Gelegegröße von gleichgroßen (extrapolierten) Vögeln ähnlich der von Sauropoden war. Da das Aussterberisiko häufig mit niedriger Reproduktionskapazität korreliert ist, impliziert dies ein geringeres Aussterberisiko großer Dinosaurier im Vergleich zu großen Säugetieren. Populationen sehr großer Dinosaurier, wie der Sauropoden, konnten vermutlich daher, über evolutionäre Zeiträume betrachtet, sehr viel länger existieren als Populationen großer Säugetiere.rn

Allosaurus fragilis nelle collezioni del Museo di Paleontologia dell'universita di Modena e Reggio-Emilia: Analisi e descrizione.

Allosaurus fragilis (Theropoda: Carnosauria) è tra i dinosauri del Giurassico Superiore meglio conosciuti grazie a numerosi scheletri rinvenuti a partire dal secolo scorso. Le collezioni del Museo Universitario Paleontologico del Dipartimento di Scienze Chimiche e Geologiche dell'Università di Modena e Reggio Emilia ospitano uno scheletro costituito da reperti originali provenienti dal Cleveland-Lloyd Dinosaur Quarry (Utah) ad oggi non descritto in dettaglio. Il temporaneo disallestimento dello scheletro per la realizzazione di una nuova struttura museale ha permesso di esaminare in dettaglio i singoli elementi scheletrici. La storia di come e quando il materiale sia giunto a Modena rimane incerta, e per questo lavoro si è raccolta tutta la documentazione storica per completare le informazioni relative all'esemplare. In questa tesi vengono inoltre descritti alcuni degli elementi più diagnostici al fine di verificare se lo scheletro rappresenta uno o più individui di Allosaurus fragilis, la specie più abbondante e meglio documentata del Cleveland-Lloyd Dinosaur Quarry. Per questo obiettivo le ossa sono state confrontate con esemplari di riferimento in letteratura e inquadrate all'interno del contesto tafonomico del sito di ritrovamento. Durante le fasi di studio, i reperti esaminati sono stati acquisiti come modelli tridimensionali ad alta risoluzione mediante tecniche fotogrammetriche. Questo per garantire fruibilità ai singoli elementi anche in seguito al riallestimento dello scheletro per fini espositivi. I dati raccolti in questa tesi, ed in particolare 1. l’analisi del contesto tafonomico e tassonomico del Cleveland-Lloyd Dinosaur Quarry; 2. il confronto morfometrico tra le ossa presenti a Modena e quelle descritte in letteratura, e 3. le caratteristiche specifiche dei reperti esaminati, permettono di chiarire numerosi aspetti legati alla storia del reperto e al numero di individui rappresentati dallo scheletro di Allosaurus fragilis del Museo di Modena.

The evolution of scarab beetles tracks the sequential rise of angiosperms and mammals

Extant terrestrial biodiversity arguably is driven by the evolutionary success of angiosperm plants, but the evolutionary mechanisms and timescales of angiosperm-dependent radiations remain poorly understood. The Scarabaeoidea is a diverse lineage of predominantly plant- and dung-feeding beetles. Here, we present a phylogenetic analysis of Scarabaeoidea based on four DNA markers for a taxonomically comprehensive set of specimens and link it to recently described fossil evidence. The phylogeny strongly supports multiple origins of coprophagy, phytophagy and anthophagy. The ingroup-based fossil calibration of the tree widely confirmed a Jurassic origin of the Scarabaeoidea crown group. The crown groups of phytophagous lineages began to radiate first (Pleurostict scarabs: 108 Ma; Glaphyridae between 101 Ma), followed by the later diversification of coprophagous lineages (crown-group age Scarabaeinae: 76 Ma; Aphodiinae: 50 Ma). Pollen feeding arose even later, at maximally 62 Ma in the oldest anthophagous lineage. The clear time lag between the origins of herbivores and coprophages suggests an evolutionary path driven by the angiosperms that first favoured the herbivore fauna (mammals and insects) followed by the secondary radiation of the dung feeders. This finding makes it less likely that extant dung beetle lineages initially fed on dinosaur excrements, as often hypothesized.

Topological invariance and spatial scaling of surface roughness in two highly eroded zones of Mexico: a comparative study

The Fractal Image Informatics toolbox (Oleschko et al., 2008 a; Torres-Argüelles et al., 2010) was applied to extract, classify and model the topological structure and dynamics of surface roughness in two highly eroded catchments of Mexico. Both areas are affected by gully erosion (Sidorchuk, 2005) and characterized by avalanche-like matter transport. Five contrasting morphological patterns were distinguished across the slope of the bare eroded surface of Faeozem (Queretaro State) while only one (apparently independent on the slope) roughness pattern was documented for Andosol (Michoacan State). We called these patterns ?the roughness clusters? and compared them in terms of metrizability, continuity, compactness, topological connectedness (global and local) and invariance, separability, and degree of ramification (Weyl, 1937). All mentioned topological measurands were correlated with the variance, skewness and kurtosis of the gray-level distribution of digital images. The morphology0 spatial dynamics of roughness clusters was measured and mapped with high precision in terms of fractal descriptors. The Hurst exponent was especially suitable to distinguish between the structure of ?turtle shell? and ?ramification? patterns (sediment producing zone A of the slope); as well as ?honeycomb? (sediment transport zone B) and ?dinosaur steps? and ?corals? (sediment deposition zone C) roughness clusters. Some other structural attributes of studied patterns were also statistically different and correlated with the variance, skewness and kurtosis of gray distribution of multiscale digital images. The scale invariance of classified roughness patterns was documented inside the range of five image resolutions. We conjectured that the geometrization of erosion patterns in terms of roughness clustering might benefit the most semi-quantitative models developed for erosion and sediment yield assessments (de Vente and Poesen, 2005).

Incremental lines of von Ebner in dinosaurs and the assessment of tooth replacement rates using growth line counts

Dinosaur dentine exhibits growth lines that are tens of micrometers in width. These laminations are homologous to incremental lines of von Ebner found in extant mammal and crocodilian teeth (i.e., those of amniotes). The lines likely reflect daily dentine formation, and they were used to infer tooth development and replacement rates. In general, dinosaur tooth formation rates negatively correlated with tooth size. Theropod tooth replacement rates negatively correlated with tooth size, which was due to limitations in the dentine formation rates of their odontoblasts. Derived ceratopsian and hadrosaurian dinosaurs retained relatively rapid tooth replacement rates through ontogeny. The evolution of dental batteries in hadrosaurs and ceratopsians can be explained by dentine formation constraints and rapid tooth wear. In combination with counts of shed dinosaur teeth, tooth replacement rate data can be used to assess population demographics of Mesozoic ecosystems. Finally, it is of historic importance to note that Richard Owen appears to have been the first to observe incremental lines of von Ebner in dinosaurs more than 150 years ago.

Revisiting the Late Jurassic-Early Cretaceous of the NW South Iberian Basin: new ages and sedimentary environments

The study of the Upper Jurassic-Lower Cretaceous deposits (Higueruelas, Villar del Arzobispo and Aldea de Cortés Formations) of the South Iberian Basin (NW Valencia, Spain) reveals new stratigraphic and sedimentological data, which have significant implications on the stratigraphic framework, depositional environments and age of these units. Moreover, these new data encourage revising the previously proposed stratigraphic correlations between the studied units and those deposited in adjacent areas of the Iberian Basin. The Higueruelas Fm was deposited in a mid-inner carbonate platform where oncolitic bars migrated by the action of storms and where oncoid production progressively decreased towards the uppermost part of the unit. The overlying Villar del Arzobispo Fm has been traditionally interpreted as an inner platform-lagoon evolving into a tidal-flat. Here it is interpreted as an inner-carbonate platform affected by storms, where oolitic shoals protected a lagoon, which had siliciclastic inputs from the continent. The Aldea de Cortés Fm has been previously interpreted as a lagoon surrounded by tidal-flats and fluvial-deltaic plains. Here it is reinterpreted as a coastal wetland where siliciclastic muddy deposits interacted with shallow fresh to marine water bodies, aeolian dunes and continental siliciclastic inputs. The contact between the Higueruelas and Villar del Arzobispo Fms, classically defined as gradual, is interpreted here as gradual and rapid, because the transition between both units comprises few meters. More importantly, the contact between the Villar del Arzobispo and Aldea de Cortés Fms, previously considered as unconformable, is here interpreted as gradual. The presence of Alveosepta in the Villar del Arzobispo Fm suggests that at least part of this unit is Kimmeridgian, unlike the previously assigned Late Tithonian-Middle Berriasian age. Consequently, the underlying Higueruelas Fm, previously considered Tithonian, should not be younger than Kimmeridgian. Accordingly, sedimentation of the Aldea de Cortés Fm, previously considered Valanginian-Hauterivian, probably started during the Tithonian and it may be considered part of the regressive trend of the Late Jurassic-Early Cretaceous cycle. This is consistent with the dinosaur faunas, typically Jurassic, described in the Villar del Arzobispo and Aldea de Cortés Fms.

The fuzzy frontier

THE STORY OF HOW FEATHERS EVOLVED IS FAR FROM OVER. IN 1868, THOMAS HUXLEY declared that dinosaurs gave rise to birds. He based his claim on Compsognathus, a 150-million-year-old dinosaur fossil from Solnhofen, Germany, whose delicate hind legs were remarkably similar to those of table fowl. The discovery seven years earlier of Archaeopteryx, a fossil bird with a long bony tail, toothed jaws and clawed fingers, had convinced many people that birds were somehow related to reptiles. But Compsognathus was the fossil that placed dinosaurs firmly in the middle of this complex evolutionary equation. Wings, claimed Huxley, must have grown out of rudimentary forelimbs. And feathers? Whether Compsognathus had them, Huxley could only guess. Nevertheless, his theory clearly required that scales had somehow transformed into feathers. The question was not just how, but why?

Developing New Tourism Services: Dinosaurs a New Drive Tourism Resource for Remote Areas

This paper examines issues encountered when developing new tourism services generally, and specific aspects relating to the development of remote area dinosaur fossil fields for tourism. It studies two sites, one in the USA and one in Australia. Access to both sites is by minor roads, and both sites are characterised by long drives separating the sites from small communities that offer limited infrastructure and few other attractions for visitors. In both areas, however, tourism is seen as one of the few possible ways to sustain existing communities in the face of declining primary-industry-based employment. In general, tourists visiting these areas are on touring holidays of two weeks’ duration or more where the attraction is the general attributes of the region as well as to a lesser extent their interest in dinosaur fossils. These provide a potential resource for remote-region economic development through commodification as a new tourism attraction. Development of dinosaur fossil finds as a tourism resource is conceptualised here as new service development. Developing new tourism services, especially in remote regions, is challenging and has not been well examined in the tourism literature. The new service development process used in this case study first examines the characteristics of the existing tourists travelling through the region. The characteristics of a number of potential market segments currently interested in dinosaur fossils were then examined and contrasted with the existing market. This is conceptualised on a specialist-generalist spectrum of interest in fossils. A study of the tourist service features associated with dinosaur fossil tourism in remote regions of the USA was conducted, leading to the identification of a number of possible incremental development opportunities. The paper then takes a strategic approach to examining potential new tourism service development related to dinosaur fossils in remote regions of Queensland, Australia. In particular, it describes use of information about existing services in similar regions as the basis for ideas about development as well as comparison between existing and potential markets.

On the tracks of the earliest dinosaurs: implications for the hypothesis of dinosaurian monophyly

From the record of dinosaurian skeletal remains it has been inferred that the origin and initial diversification of dinosaurs were rapid events, occupying an interval of about 5 million years in the Late Triassic. By contrast numerous reports of dinosauroid tracks imply that the emergence of dinosaurs was a more protracted affair extending through much of the Early and Middle Triassic. This study finds no convincing evidence of dinosaur tracks before the late Ladinian. Each of the three dinosaurian clades - Theropoda, Sauropodomorpha, Ornithischia - produced a unique track morphotype that appears to be an independent modification of the chirotherioid pattern attributed to stem-group archosaurs (thecodontian reptiles). The existence of three divergent track morphotypes is consistent with the concept of dinosaurian polyphyly but can be reconciled with the hypothesis of dinosaurian monophyly only by invoking many and rapid reversals in the locomotor anatomy of early dinosaurs. The origin of dinosaurs was not the correlate or consequence of any single event or process, be it global change, competitive replacement, or opportunism in the wake of mass extinction. Instead the origin of dinosaurs is envisaged as a series of three cladogenetic events over an interval of at least 10 million years and possibly as much as 25 million years. This scenario of dinosaurian polyphyly is as well-supported by fossil evidence as is the currently favoured view of dinosaurian monophyly.

Revisiting the Late Jurassic-Early Cretaceous of the NW South Iberian Basin: new ages and sedimentary environments

The study of the Upper Jurassic-Lower Cretaceous deposits (Higueruelas, Villar del Arzobispo and Aldea de Cortés Formations) of the South Iberian Basin (NW Valencia, Spain) reveals new stratigraphic and sedimentological data, which have significant implications on the stratigraphic framework, depositional environments and age of these units. The Higueruelas Fm was deposited in a mid-inner carbonate platform where oncolitic bars migrated by the action of storms and where oncoid production progressively decreased towards the uppermost part of the unit. The overlying Villar del Arzobispo Fm has been traditionally interpreted as an inner platform-lagoon evolving into a tidal-flat. Here it is interpreted as an inner-carbonate platform affected by storms, where oolitic shoals protected a lagoon, which had siliciclastic inputs from the continent. The Aldea de Cortés Fm has been previously interpreted as a lagoon surrounded by tidal-flats and fluvial-deltaic plains. Here it is reinterpreted as a coastal wetland where siliciclastic muddy deposits interacted with shallow fresh to marine water bodies, aeolian dunes and continental siliciclastic inputs. The contact between the Higueruelas and Villar del Arzobispo Fms, classically defined as gradual, is also interpreted here as rapid. More importantly, the contact between the Villar del Arzobispo and Aldea de Cortés Fms, previously considered as unconformable, is here interpreted as gradual. The presence of Alveosepta in the Villar del Arzobispo Fm suggests that at least part of this unit is Kimmeridgian, unlike the previously assigned Late Tithonian-Middle Berriasian age. Consequently, the underlying Higueruelas Fm, previously considered Tithonian, should not be younger than Kimmeridgian. Accordingly, sedimentation of the Aldea de Cortés Fm, previously considered Valangian-Hauterivian, probably started during the Tithonian and it may be considered part of the regressive trend of the Late Jurassic-Early Cretaceous cycle. This is consistent with the dinosaur faunas, typically Jurassic, described in the Villar del Arzobispo and Aldea de Cortés Fms.

Systematic review of Late Jurassic sauropods from the Museu Geológico collections (Lisboa, Portugal)

The Museu Geológico collections house some of the first sauropod references of the Lusitanian Basin Upper Jurassic record, including the Lourinhasaurus alenquerensis and Lusotitan atalaiensis lectotypes, previously considered as new species of the Apatosaurus and Brachiosaurus genera, respectively. Several fragmentary specimens have been classical referred to those taxa, but the most part of these systematic attributions are not supported herein, excluding a caudal vertebra from Maceira (MG 8804) considered as cf. Lusotitan atalaiensis. From the material housed in the Museu Geológico were identified basal eusauropods (indeterminate eusauropods and turiasaurs) and neosauropods (indeterminate neosauropods, diplodods and camarasaurids and basal titanosauriforms). Middle caudal vertebrae with lateral fossae, ventral hollow border by pronounced ventrolateral crests and quadrangular cross-section suggest for the presence of diplodocine diplodocids in north area of the Lusitanian Basin Central Sector during the Late Jurassic. A humerus collected from Praia dos Frades (MG 4976) is attributed to cf. Duriatitan humerocristatus suggesting the presence of shared sauropod forms between the Portugal and United Kingdom during the Late Jurassic. Duriatitan is an indeterminate member of Eusauropoda and the discovery of new material in both territories is necessary to confirm this systematic approach. The studied material is in according with the previous recorded paleobiodiversity for the sauropod clade during the Portuguese Late Jurassic, which includes basal eusauropods (including turiasaurs), diplodocids and macronarians (including camarasaurids and basal titanosauriforms).

Die Saurierfährten im Naturdenkmal Münchehagen

Nearly 256 footprints of sauropods are exposed on the floor of an abandoned quarry, situated west of Hannover, where quartzitic sandstones of Berriasian age were formeriy exploited. A part of the traces can be grouped to 8 tracks, one of which was named Rotundichnus muenchehagensis by Hendricks 1981. Additionally, a track composed of bird-like footprints of a biped dinosaur is present. The dinosaurs lived within the semiaquatic, densely wooded estuary System, which was protected by sand bars against the open sea of the Lower Saxonian Basin.

Das Kluftsystem im Bereich des Naturdenkmals "Saurierfährten Münchehagen"

The joints at the site of the dinosaur tracks in Muenchehagen form a conspicuous rhomboid pattern in a widely exposed bedding surface of the local quarry. An approximately west-trending set of joints is radially orientated with regard to the shape of the Rehburg salt pillow indicating a genetic relation to salt flow. The second set of joints trends approximately NW and is associated with arrays of dextral shear joints. Its formation is attributed to salt pillow formation and/or a regional deformation plan. This deformation plan presumably existed during the Alpine orogeny. The preservation potential of the dinosaur tracks is considerably decreased by the joint System.