Amargatitanis macni is Really a Dicraeosaurid Sauropod

Reappraisal of the Early Cretaceous sauropod dinosaur Amargatitanis macni (Apesteguía, 2007), from northwestern Patagonia, Argentina

Authors:

Gallina et al

Abstract:

Amargatitanis macni Apesteguía, 2007 was described as a purported titanosaur sauropod. That referral is significant because Amargatitanis would represent one of the oldest known members of Titanosauria. However, this referral and even the systematic validity of the taxon were questioned. Here, all the available remains of the taxon are evaluated including a description of unpublished elements. The identity of the type material is discussed based on a first-hand examination of the specimens and evaluation of the original field notes as reliable evidence for bone association. The original holotype of Amargatitanis is a chimaera, as pointed out by previous authors. Herein a new, modified holotype for Amargatitanis is proposed. This analysis presents a revised diagnosis for Amargatitanis macni as a valid taxon, and description of unpublished material clarifies the anatomy of this sauropod dinosaur. The inclusion of Amargatitanis macni in an updated phylogenetic analysis revealed the presence of a second species of the family Dicraeosauridae in the La Amarga Formation, suggesting that, at present, there is no record of titanosaur body fossils in Patagonia prior to Cenomanian times.

Turns out Sauropods Liked Pasta

First sauropod bones from Italy offer new insights on the radiation of Titanosauria between Africa and Europe

Authors:

Dal Sasso et al

Abstract:

Here we describe the first sauropod skeletal remains from the Italian peninsula that also represent the earliest record of titanosaurs in Southern Europe. Scattered bones, including an almost complete anterior caudal vertebra, were found in Cretaceous (Aptian–Albian) marine deposits, some 50 km East of Rome. The vertebra shows a bizarre and perhaps unique orientation of the zygapophyseal articular facets that renders their interpretation problematic. Phylogenetic retrofitting tests support the placement of the Italian titanosaur among basal lithostrotians. Palaeobiogeographic analysis based on the resulting phyletic relationships suggests an Afro-Eurasian route for the ancestors of the Italian titanosaur, a scenario compatible with the palaeogeographic evolution of the Italian microplates during the Cretaceous. Together with previously recorded titanosaurian-like ichnites from a Cenomanian locality in Latium, this new find suggests a quite long emersion for the Apenninic carbonate platform. We suggest that the Italian titanosaur was member of a population that crossed the western Tethys Sea through a “filtering bridge” composed of a chain of ephemeral islands and peninsulae, known as Periadriatic (Adria) carbonate platforms, that connected sporadically Africa and Europe since the Early Cretaceous.

A Rapetosaurus Titanosaur Sauropod Lived Fast, Died Young in Cretaceous Madagascar

Precocity in a tiny titanosaur from the Cretaceous of Madagascar

Authors:

Rogers et al

Abstract:

Sauropod dinosaurs exhibit the largest ontogenetic size range among terrestrial vertebrates, but a dearth of very young individuals has hindered understanding of the beginning of their growth trajectory. A new specimen of Rapetosaurus krausei sheds light on early life in the smallest stage of one of the largest dinosaurs. Bones record rapid growth rates and hatching lines, indicating that this individual weighed ~3.4 kilograms at hatching. Just several weeks later, when it likely succumbed to starvation in a drought-stressed ecosystem, it had reached a mass of ~40 kilograms and was ~35 centimeters tall at the hip. Unexpectedly, Rapetosaurus limb bones grew isometrically throughout their development. Cortical remodeling, limb isometry, and thin calcified hypertrophic metaphyseal cartilages indicate an active, precocial growth strategy.

University of Liverpool have developed computer models of the bodies of sauropod dinosaurs

Scientists from the University of Liverpool have developed computer models of the bodies of sauropod dinosaurs to examine the evolution of their body shape.

Sauropod dinosaurs include the largest land animals to have ever lived. Some of the more well-known sauropods include Diplodocus, Apatosaurus and Brontosaurus. They are renowned for their extremely long necks, long tails as well as four thick, pillar-like legs and small heads in relation to their body.

To date, however, there have been only limited attempts to examine how this unique body-plan evolved and how it might be related to their gigantic body size. Dr Karl Bates from the University's Department of Musculoskeletal Biology and his colleagues used three-dimensional computer models reconstructing the bodies of sauropod dinosaurs to analyse how their size, shape and weight-distribution evolved over time.

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A Juvenile Barosaurs (sauropod) From Jurassic Utah also had an Avian-like Airsac Respiratory System

A juvenile sauropod dinosaur from the Late Jurassic of Utah, U.S.A., presents further evidence of an avian style air-sac system

Authors:

Melstrom et al

Abstract:

Well-preserved, articulated juvenile sauropod dinosaur material is very rare, hindering attempts to understand ontogenetic changes within the clade. Here, we describe an exceptionally preserved partial skeleton of a Barosaurus from the Morrison Formation of Dinosaur National Monument, Utah, U.S.A., that is only about one-third adult size. This small size and the lack of fusion of neurocentral and costovertebral sutures indicate that the individual is a juvenile. Apomorphy-based taxonomic identification of the specimen combined with the excellent preservation of its vertebral column allows documentation of both serial and ontogenetic morphological changes in Barosaurus. Each vertebra underwent substantial morphological change in the relative height of the neural spine and location of the zygapophyseal and diapophyseal articular facets during ontogeny but not in the degree of bifurcation of the neural spines. Pneumaticity in the dorsal vertebrae varies serially: large pneumatic fossae punctuate the centra of dorsal vertebrae 1–4 and 8–9, whereas these spaces are occupied by shallow depressions in dorsal vertebrae 5–7. This represents the first known caudal dorsal pneumatic hiatus in a sauropod dinosaur, which suggests that separate air sacs pneumatized the anterior and posterior regions of the dorsal vertebral column, congruent with the pattern observed in non-avian and avian theropod dinosaurs and the presence of an avian-style lung in sauropods.

Very Diverse Dinosaur Trackway has Ornithopod and Pterosaur Traces Amongst Lots of Theropod and Sauropods Tracks

A diverse saurischian (theropod–sauropod) dominated footprint assemblage from the Lower Cretaceous Jiaguan Formation in the Sichuan Basin, southwestern China: A new ornithischian ichnotaxon, pterosaur tracks and an unusual sauropod walking pattern

Authors:

Xing et al

Abstract:

A sample of fallen blocks of fluvial sandstone from the Lower Cretaceous Jiaguan Formation of Sichuan Province yielded an assemblage of dinosaur and pterosaur tracks preserved as natural impressions and casts. Collectively the assemblage reveals 132 tracks representing at least 30 trackways of tridactyl and didactyl theropods, sauropods, ornithopods and pterosaurs. Ichnotaxonomically, the trackways of small tridactyl theropods (pes lengths 7–18 cm) are indeterminable, whereas the trackway of a small didactyl dromaeosaur (pes length up to 7.5 cm) is tentatively assigned to cf. Velociraptorichnus. The sauropod trackways are assigned to cf. Brontopodus based on the medium to nearly wide-gauge pattern. Other characteristics are the U-shaped manus and strong heteropody. One sauropod trackway shows a peculiar pattern with a lack of left manus imprints, and an unusual position and rotation of right manus imprints. Different scenarios and explanations for this phenomenon are discussed. Ornithopod trackways are the most abundant in the sample and characterized by pes imprints of a small biped that are assigned here to the new ichnospecies Caririchnium liucixini. It is characterized by an unusual broad shape and weak mesaxony. Bivariate analysis of different Caririchnium ichnospecies reveals increasing mesaxony toward the larger forms, a trend that is the reverse of typical theropod ichnotaxa, where large imprints have weak mesaxony. Three isolated, small pterosaur tracks (two manus, one pes) are visible on a single surface. They show strong similarities to the widespread ichnogenus Pteraichnus. This is the ninth report of tetrapod tracks from the Jiaguan Formation in recent years and represents one of the most diverse assemblages recorded to date. It is also rare evidence of typical didactyl dromaeosaur tracks and the co-occurrence of sauropod and ornithopod tracks in a fluvial depositional environment representing arid climate conditions.
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A Late Cretaceous Crocodilian Nest was Hidden in a Sauropod Nest in India

Crocodilian Nest in a Late Cretaceous Sauropod Hatchery from the Type Lameta Ghat Locality, Jabalpur, India

Authors:

Srivastava et al

Abstract:

The well-known Late Cretaceous Lameta Ghat locality (Jabalpur, India) provides a window of opportunity to study a large stable, near shore sandy beach, which was widely used by sauropod dinosaurs as a hatchery. In this paper, we revisit the eggs and eggshell fragments previously assigned to lizards from this locality and reassign them to crocodylomorphs. Several features point to a crocodilian affinity, including a subspherical to ellipsoidal shape, smooth, uneven external surface, discrete trapezoid shaped shell units with wide top and narrow base, basal knobs and wedge shaped crystallites showing typical inverted triangular extinction under crossed nicols. The crocodylomorph eggshell material presented in this paper adds to the skeletal data of these most probably Cretaceous-Eocene dryosaurid crocodiles.

A Highly Diverse Sauropod Fauna in the Earliest Cretaceous South Africa

High diversity in the sauropod dinosaur fauna of the Lower Cretaceous Kirkwood Formation of South Africa: Implications for the Jurassic–Cretaceous transition

Authors:

McPhee et al

Abstract:

The Kirkwood Formation of South Africa has long been recognized as having the potential to fill an important gap in the Mesozoic terrestrial fossil record. As one of the few fossil-bearing deposits from the lowermost Cretaceous, the Kirkwood Formation provides critical information on terrestrial ecosystems at the local, subcontinental (southern Gondwana), and global scale during this poorly sampled time interval. However, until recently, the dinosaurian fauna of the Kirkwood Formation, especially that pertaining to Sauropoda, has remained essentially unknown. Here we present comprehensive descriptions of several relatively well-preserved sauropod vertebrae collected from exposures throughout the formation. We identify at least four taxonomically distinct groups of sauropod, comprising representatives of Diplodocidae, Dicraeosauridae, Brachiosauridae, and a eusauropod that belongs to neither Diplodocoidea nor Titanosauriformes. This represents the first unequivocal evidence of these groups having survived into the earliest Cretaceous of Africa. The taxonomic composition of the Kirkwood Formation shows strong similarities to Upper Jurassic deposits, and raises questions regarding the taxonomic decline across the Jurassic/Cretaceous boundary that has been previously inferred for Sauropoda. Investigation of the sauropod fossil record of the first three geological stages of the Cretaceous suggests that reconstruction of sauropod macroevolutionary patterns is complicated by a combination of sampling bias, an uneven and poorly dated rock record, and spatiotemporal disparity in the global disappearance of certain sauropod groups. Nonetheless, the close ecological relationship consistently observed between Brachiosauridae and Diplodocidae, as well as their approximately synchronous decline, suggests some equivalence in response to the changing faunal dynamics of the Early Cretaceous.

Dinosaur Tracks From Middle Jurassic Isle of Skye

A newly discovered collection of rare dinosaur tracks is helping scientists shed light on some of the biggest animals ever to live on land.

Hundreds of footprints and handprints made by plant-eating sauropods around 170 million years ago have been found on the Isle of Skye in Scotland.

The discovery - which is the biggest dinosaur site yet found in Scotland - helps fill an important gap in the evolution the huge, long-necked animals, which were the biggest of the dinosaurs.

Scientists at the University of Edinburgh identified the tracks in layers of rock, which would have been at the bottom of a shallow, salt water lagoon when the prints were made.

By analysing the structure of the footprints, the team found that the dinosaurs were early, distant relatives of more well-known species, such as Brontosaurus and Diplodocus. The Skye dinosaurs likely grew to at least 15 metres in length and weighed more than 10 tonnes.

The footprints - the largest of which is 70 cm in diameter - are the first sauropod tracks to be found in Scotland. Until now, the only evidence that sauropods lived in Scotland came from a small number of bone and teeth fragments.

Fossils from the Middle Jurassic Period are extremely rare, and the Isle of Skye is one of the few places in the world where they can be found.

The discovery is helping scientists to reimagine the habitats and lifestyles of the world's biggest dinosaurs. Together with similar tracks found recently in other parts of the world, the Skye trackways reveal that sauropods spent lots of time in coastal areas and shallow water. It was previously thought that large dinosaurs were purely land-dwellers.

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Were Diplodocid Sauropods Endemic to North America During the Late Jurassic

First report of Apatosaurus (Diplodocidae: Apatosaurinae) from the Cleveland-Lloyd Quarry in the Upper Jurassic Morrison Formation of Utah: abundance, distribution, paleoecology, and taphonomy of an endemic North American sauropod clade

Authors:

Foster et al

Abstract:

A cervical vertebra preserved at the famous and productive Cleveland-Lloyd Dinosaur Quarry in the Upper Jurassic Morrison Formation of Utah is that of an Apatosaurus, a sauropod dinosaur genus not previously recognized at the site and the first new dinosaur taxon identified at the site in years. The presence of Apatosaurus at a mudstone site dominated by other taxa, both theropod and sauropod, suggests a pattern of preservation within the Morrison Formation in which sites in fine-grained sediments yield dramatically uneven relative abundances of dinosaurs, with variable dominant taxa by site, compared with more time-averaged and attritional coarse-grained channel sandstone deposits. In addition, the continued demonstration of the wide-spread occurrence and abundance of Apatosaurus within the Morrison Formation, and the absence of its clade among diplodocid faunas on other continents, suggest that this group may have been endemic to North America during the Late Jurassic and that it may have originated there, though this is far from clear.

Were the Tidal Flats of Maastrichtian Cretaceous Catalonia a Safe Haven for Sauropods From Theropods?

Transitional environments of the lower Maastrichtian South-Pyrenean Basin (Catalonia, Spain): The Fumanya Member tidal flat

Authors:

Oms et al

Abstract:

Sedimentological, palaeontological and geochemical data provide detailed evidence of a marine-to-lagoon environmental succession around the Campanian-Maastrichtian boundary in the Ibero-Armorican domain. This regression is recorded by the succession of several environments of the south-central Pyrenees basin: open marine mixed shelf, marine restricted mixed shelf (both rudist-rich), tidal flat, lagoon and fluvial dominated. The tidal flat setting belongs to the Fumanya Member here described, which is the base of the Posa and Massana formations (Tremp Group). The Fumanya Member is 5 m thick, is built up of marly limestones and was an elongated tidal mudflat (100 km long, 25 km wide) developed in a foreland trough and was separated from the Atlantic Ocean by an island-barrier system. In the lagoon environment, marginal marine waters and continental fresh waters alternated as documented by geochemistry and fossil molluscs. The Fumanya Member is a dinosaur megatracksite, reporting the roaming activity only of sauropods in tidal flats, a likely secure area against predators. Feeding activity of these herbivores took place in the lagoonal-lacustrine environments of the Posa Formation above the Fumanya Member.

Wait! Is Brontosaurus Really a Valid Taxon?!

Although well known as one of the most iconic dinosaurs, Brontosaurus (the 'thunder lizard') has long been considered misclassified. Since 1903, the scientific community has believed that the genus Brontosaurus was in fact the Apatosaurus. Now, an exhaustive new study by palaeontologists from Portugal and the UK provides conclusive evidence that Brontosaurus is distinct from Apatosaurus and as such can now be reinstated as its own unique genus.

Brontosaurus is one of the most charismatic dinosaurs of all time, inspiring generations of children thanks to its size and evocative name. However, as every armchair palaeontologist knows, Brontosaurus was in fact a misnomer, and it should be correctly referred to as Apatosaurus. At least, this is what scientists have believed since 1903, when it was decided that the differences between Brontosaurus excelsus and Apatosaurus were so minor that it was better to put them both in the same genus. Because Apatosaurus was named first, it was the one that was used under the rules of scientific naming.

In fact, of course, the Brontosaurus was never really gone - it was simply treated as a species of the genus Apatosaurus: Apatosaurus excelsus. So, while scientists thought the genus Brontosaurus was the same as Apatosaurus, they always agreed that the species excelsus was different from other Apatosaurus species. Now, palaeontologists Emanuel Tschopp, Octávio Mateus, and Roger Benson say that Brontosaurus was a unique genus all along.

[...]

But now, in a new study published in the peer reviewed open access journal PeerJ and consisting of almost 300 pages of evidence, a team of scientists from Portugal and the UK have shown that Brontosaurus was distinct from Apatosaurus after all - the thunder lizard is back!

How can a single study overthrow more than a century of research? "Our research would not have been possible at this level of detail 15 or more years ago", explains Emanuel Tschopp, a Swiss national who led the study during his PhD at Universidade Nova de Lisboa in Portugal, "in fact, until very recently, the claim that Brontosaurus was the same as Apatosaurus was completely reasonable, based on the knowledge we had." It is only with numerous new findings of dinosaurs similar to Apatosaurus and Brontosaurus in recent years that it has become possible to undertake a detailed reinvestigation of how different they actually were.

In science, the distinction between species and genera is without clear rules. Does this mean that the decision to resurrect Brontosaurus is just a matter of personal preference? "Not at all", explains Tschopp, "we tried to be as objective as possible whenever making a decision which would differentiate between species and genus". The researchers applied statistical approaches to calculate the differences between other species and genera of diplodocid dinosaurs, and were surprised by the result. "The differences we found between Brontosaurus and Apatosaurus were at least as numerous as the ones between other closely related genera, and much more than what you normally find between species," explained Roger Benson, a co-author from the University of Oxford.

Therefore, Tschopp and colleagues have concluded that it is now possible to resurrect Brontosaurus as a genus distinct from Apatosaurus. "It's the classic example of how science works", said Professor Mateus, a collaborator on the research. "Especially when hypotheses are based on fragmentary fossils, it is possible for new finds to overthrow years of research."

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A Pathology From Digging too Much From a Tithonian Jurassic Camarasaurid Sauropod

Pathological phalanges in a camarasaurid sauropod dinosaur and implications on behaviour

Authors:

Tschopp et al

Abstract:

Several types of pathological bony overgrowth are known from various dinosaur taxa but, except for stress fractures, are rarely reported from appendicular elements. Herein we describe pathological manual and pedal phalanges of a camarasaurid sauropod (SMA 0002), which show features rarely recognised in non-avian dinosaurs. They include lateral osteophytes and smoothing of phalangeal articular surfaces, a deep pit, proximal enthesophytes in pedal unguals, distal overgrowth associated with a fracture, and a knob-like overgrowth lateral to the distal condyles of a pedal phalanx. Their causes were assessed by means of visual examination, CT scans, and bone histology, where possible. The lateral osteophytes are interpreted as symptoms of osteoarthritis. The ossified tendon insertions in the unguals are most probably the result of prolonged, heavy use of the pedal claws, possibly for scratchdigging. The distal overgrowth is interpreted to have developed due to changed stress regimes, and to be the cause for the fracture. The deep pit represents most likely a case of osteochondrosis, whereas the knob-like overgrowth likely represents a post-traumatic phenomenon not previously reported in dinosaurs. The study confirms that a rigorous assessment of pathologies can yield information about behaviour in long-extinct animals.

Exploring the Paleobiodiversity of Sauropods in Cretaceous South America

Cretaceous sauropod diversity and taxonomic succession in South America

Authors:

de Jesus Faria et al

Abstract:

The South American sauropod dinosaurs fossil record is one of the world’s most relevant for their abundance (51 taxa) and biogeographical implications. Their historical biogeography was influenced by the continental fragmentation of Gondwana. The scenery of biogeographic and stratigraphic distributions can provide new insight into the causes of the evolution of the sauropods in South America. One of the most important events of the sauropods evolution is the progressive replacement of Diplodocimorpha by the Titanosauriformes during the early Late Cretaceous. The fluctuation of the sea levels is frequently related to the diversity of sauropods, but it is necessary to take into account the geological context in each continent. During the Maastrichthian, a global sea level drop has been described; in contrast, in South America there was a significant rise in sea level (named ‘Atlantic transgression’) which is confirmed by sedimentary sequences and the fossil record of marine vertebrates. This process occurred during the Maastrichtian, when the hadrosaurs arrived from North America. The titanosaurs were amazingly diverse during the Late Cretaceous, both in size and morphology, but they declined prior to their final extinction in the Cretaceous/Paleocene boundary (65.5Yrs).

Relic Sauropod Lineage From Berriasian/Valanginian Cretaceous North America

The oldest Cretaceous North American sauropod dinosaur

Authors:

D'emic et al

Abstract:

Sauropod dinosaurs have been found in sediments dating to most of the Cretaceous Period on all major Mesozoic landmasses, but this record is spatiotemporally uneven, even in relatively well-explored North American sediments. Within the 80 million-year-span of the Cretaceous, no definitive sauropod occurrences are known in North America from two ca. 20–25 million-year-long gaps, one from approximately the Berriasian–Barremian and the other from the mid-Cenomanian–late Campanian. Herein, we present an undescribed specimen that was collected in the middle part of the twentieth century that expands the known spatiotemporal distribution of Early Cretaceous North American sauropods, partially filling the earlier gap. The material is from the Berriasian–Valanginian-aged (ca. 139 Ma) Chilson Member of the Lakota Formation of South Dakota and appears to represent the only non-titanosauriform from the Cretaceous of North America or Asia. It closely resembles Camarasaurus and may represent a form closely related to that genus that persisted across the Jurassic–Cretaceous boundary.

Sauropod Niche Partitioning in the Late Jurassic Morrison Formation

How the largest animals to have ever walked the Earth fed, and how this allowed them to live alongside one another in prehistoric ecosystems is the subject of new research from the University of Bristol and the Natural History Museum, London.

The sauropods – large, long-necked plant-eating dinosaurs such as Diplodocus and Brachiosaurus – dominated the land between 210 and 65 million years ago. They were the largest land animals of all time, with the biggest weighing 80 tonnes (more than 11 elephants) and would have needed vast amounts of food.

Despite this, multiple sauropod species often lived alongside each other. The most notable example is the community of the Late Jurassic Morrison Formation, a distinctive sequence of sedimentary rock in the western United States from which over 10 species of sauropod are known.

How so many giant herbivores could have coexisted has long been a mystery: even the highly diverse faunas seen in modern Africa only support one truly gigantic species, the elephant. This is made even more puzzling by the harsh, semi-arid environment of the Morrison Formation during the Jurassic, which would have limited plant growth.

A study conducted by David Button, a PhD student in Bristol's School of Earth Sciences and the Natural History Museum, and colleagues used a novel combination of approaches to investigate this problem.

Although sauropods were gigantic, their heads were comparatively very small and so how they ingested enough food has puzzled many scientists. The researchers focussed on the skull and jaws of sauropods, using a variety of biomechanical techniques to investigate how they functioned and what this would mean for sauropod ecology.

Using CT scans, the researchers digitally reconstructed the skulls of the sauropods Camarasaurus and Diplodocus, along with the jaw and neck muscles of both species from the traces left on the bones where these muscles were attached in life. These two species are very common in the Morrison Formation, and are known to have widely co-existed. From this data, a biomechanical computer model of the skull of Camarasaurus was built using Finite Element Analysis (FEA), a modelling technique often employed in engineering and design to calculate stress and strain distribution in complex shapes. This model was then compared to a pre-existing model of Diplodocus in order to investigate how the dinosaurs fed.

David Button said: "Our results show that although neither could chew, the skulls of both dinosaurs were sophisticated cropping tools. Camarasaurus had a robust skull and strong bite, which would have allowed it to feed on tough leaves and branches. Meanwhile, the weaker bite and more delicate skull of Diplodocus would have restricted it to softer foods like ferns. However, Diplodocus could also have used its strong neck muscles to help it detach plant material through movements of the head. This indicates differences in diet between the two dinosaurs, which would have allowed them to coexist."

The researchers also used a series of biomechanical measurements from other sauropod species to calculate the functional disparity in their skulls and jaws and found that other Morrison Formation sauropods were also highly varied in feeding adaptations, suggesting different diets.

Co-author, Professor Emily Rayfield of the University of Bristol said: "In modern animal communities differences in diet such as this – termed 'dietary niche partitioning' – allow multiple similar species to coexist by reducing competition for food. Although, dietary niche partitioning has been suspected between Morrison Formation sauropods based on their structural features and patterns of tooth-wear, this is the first study to provide strong, numerical, biomechanical evidence for its presence in this fossil community."

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How Species Rich Were the Titanosaur Sauropods of South America During the Campanian/Maastrichtian Cretaceous?

Species Richness and Evidence of Random Patterns in Assemblages of South American Titanosauria during the Late Cretaceous (Campanian–Maastrichtian)

Authors:

Silva Viera et al

Abstract:

The Titanosauria were much diversified during the Late Cretaceous, but paleobiological information concerning these sauropods continues to be scarce and no studies have been conducted utilizing modern methods of community analysis to infer possible structural patterns of extinct assemblages. The present study sought to estimate species richness and to investigate the existence of structures in assemblages of the South American Titanosauria during the Late Cretaceous. Estimates of species richness were made utilizing a nonparametric estimator and null models of species co-occurrences and overlapping body sizes were applied to determine the occurrence of structuring in this assemblages. The high estimate of species richness (n = 57) may have been influenced by ecological processes associated with extinction events of sauropod groups and with the structures of the habitats that provided abundant support to the maintenance of large numbers of species. The pseudocommunity analysis did not differ from that expected by chance, indicating the lack of structure in these assemblages. It is possible that these processes originated from phylogenetic inertia, associated with the occurrence of stabilized selection. Additionally, stochastic extinction events and historical factors may also have influenced the formation of the titanosaurian assemblages, in detriment to ecological factors during the Late Cretaceous. However, diagenetic and biostratinomic processes, influenced by the nature of the sedimentary paleoenvironment, could have rendered a random arrangement that would make assemblage structure undetectable.

Mapping Sauropod Paleodiversity Geographically

In modern scientific researches of biological direction the geographic information systems (GIS) are increasingly used. For example, GIS technology is successfully applied in the study of patterns of spatial and temporal distribution of biological objects with taking into account the unique features of the environment. Typically, a GIS is used for the analysis of current events and / or the future forecast, but they are also useful for the study of the fossils, living conditions in the distant past, changes in biodiversity and for determining historical patterns of biosphere evolution.

Convenience of GIS for integrated paleontological studies is due to the combination of database management systems functionality, editors of raster and vector graphics and a variety of analytical tools.

Over the last decades of paleontological researches a huge number of fossils belonging to a variety of species of animals, plants and microorganisms has been found. For a comprehensive qualitative analysis of this information it is not enough to draw on the paper map a certain amount of points. Maximum efficiency of the analysis can be achieved by creating a database and its integration with GIS. But if not so long ago each individual researcher or a research institute tried to do their own, as a rule, small databases containing information gathered only by them, but now there is a fundamentally new approach to automate many operations and combine the efforts of many scientists and research teams from all over the world. The projects that implement in practice, such approaches already exist. Paleobiology Database (Paleontological database) can be considered as one of them, 350 specialists from 133 institutions in 24 countries took part in this work. Currently this database contains information on more than a million found fossils, and it is open and available for use under the license of Creative Commons.

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Rukwatitan bisepultus: a new Endemic Titanosaurian Sauropod from Albian/Cenomanian Cretaceous Tanzania

Ohio University paleontologists have identified a new species of titanosaurian, a member of the large-bodied sauropods that thrived during the final period of the dinosaur age, in Tanzania. Although many fossils of titanosaurians have been discovered around the globe, especially in South America, few have been recovered from the continent of Africa.

The new species, named Rukwatitan bisepultus, was first spotted by scientists embedded in a cliff wall in the Rukwa Rift Basin of southwestern Tanzania. Using the help of professional excavators and coal miners, the team unearthed vertebrae, ribs, limbs and pelvic bones over the course of two field seasons.

CT scans of the fossils, combined with detailed comparisons with other sauropods, revealed unique features that suggested an animal that was different from previous finds—including those from elsewhere in Africa, according to a study the team published today in the Journal of Vertebrate Paleontology.

"Using both traditional and new computational approaches, we were able to place the new species within the family tree of sauropod dinosaurs and determine both its uniqueness as a species and to delineate others species with which it is most closely related," said lead author Eric Gorscak, a doctoral student in biological sciences at Ohio University.

Rukwatitan bisepultus lived approximately 100 million years ago during the middle of the Cretaceous Period. Titanosaurian sauropods, the group that includes Rukwatitan, were herbivorous dinosaurs known for their iconic large body sizes, long necks and wide stance. Although not among the largest of titanosaurians, Rukwatitan is estimated to have a forelimb reaching 2 meters and may have weighed as much as several elephants.

The dinosaur's bones exhibit similarities with another titanosaurian, Malawisaurus dixeyi, previously recovered in Malawi. But the two southern African dinosaurs are distinctly different from one another, and, most notably, from titanosaurians known from northern Africa, said co-author Patrick O'Connor, a professor of anatomy in the Ohio University Heritage College of Osteopathic Medicine.

The fossils of middle Cretaceous crocodile relatives from the Rukwa Rift Basin also exhibit distinctive features when compared to forms from elsewhere on the continent.

"There may have been certain environmental features, such as deserts, large waterways and/or mountain ranges, that would have limited the movement of animals and promoted the evolution of regionally distinct faunas," O'Connor said. "Only additional data on the faunas and paleo environments from around the continent will let us further test such hypotheses."

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Dreadnoughtus schrani: The new MASSIVE Titanosaur from Campanian/Maastrichtian Cretaceous Patagonia

A Gigantic, Exceptionally Complete Titanosaurian Sauropod Dinosaur from Southern Patagonia, Argentina

Authors:

Lacovara et al

Abstract:

Titanosaurian sauropod dinosaurs were the most diverse and abundant large-bodied herbivores in the southern continents during the final 30 million years of the Mesozoic Era. Several titanosaur species are regarded as the most massive land-living animals yet discovered; nevertheless, nearly all of these giant titanosaurs are known only from very incomplete fossils, hindering a detailed understanding of their anatomy. Here we describe a new and gigantic titanosaur, Dreadnoughtus schrani, from Upper Cretaceous sediments in southern Patagonia, Argentina. Represented by approximately 70% of the postcranial skeleton, plus craniodental remains, Dreadnoughtus is the most complete giant titanosaur yet discovered, and provides new insight into the morphology and evolutionary history of these colossal animals. Furthermore, despite its estimated mass of about 59.3 metric tons, the bone histology of the Dreadnoughtus type specimen reveals that this individual was still growing at the time of death.