Caudal pneumaticity in derived titanosaurs (Dinosauria: Sauropoda)

Among extant vertebrates, only birds have a respiratory system associated with pneumatic diverticula. However, several extinct clades also had pneumatic diverticula, including the sauropod dinosaurs. Among sauropods, Saltasaurini are characterized by extreme postcranial pneumaticity, which extends as far down the spinal column as the posterior caudal vertebrae. In this paper the pneumatic foramina in both the neural arches and the centra are described in detail, and the relative proportion of air spaces in the caudal vertebrae is established, revealing that the skeleton of Rocasaurus muniozi was more pneumatized than that of Neuquensaurus australis, with Saltasaurus loricatus intermediate. The level of pneumatization varies between the three saltasaurine taxa: in Neuquensaurus, only the neural arch is pneumatized, whereas in the other two saltasaurines both neural arches and centra are pneumatized. This allows us to hypothesize that the timing of pneumatization varied between the three species, with Rocasaurus muniozi pneumatized earliest in ontogeny. This ontogenetic pattern is correlated with evolutionary derivation: the most derived taxa show pneumatization in both the neural arch and the centrum.     

New rebbachisaurid (Dinosauria: Sauropoda) material from the Wessex Formation (Barremian,Early Cretaceous), Isle of Wight,United Kingdom

Rebbachisauridae is a poorly understood clade of diplodocoid sauropod dinosaurs, currently known only from the Cretaceous of Africa, Europe and South America. European representatives are particularly rare and fragmentary. Here, we report an anterior caudal vertebra from the Barremian (Early Cretaceous) Wessex Formation of the Isle of Wight, off the southern coast of England. This specimen possesses several features known only in rebbachisaurids and shares two synapomorphies with the Afro-European taxa Demandasaurus darwini and Nigersaurus taqueti, both pertaining to the morphology of the neural spine. These features are the development of triangular lateral processes and the presence of an elliptical fossa on the lateral surface, bounded by the lateral lamina and postspinal rugosity. The Isle of Wight specimen also shares several features solely with Demandasaurus, indicating a close relationship with the Spanish taxon. These include the presence of a hyposphenal ridge, as well as an anteriorly excavated caudal rib that is restricted almost entirely to the neural arch. However, it differs from Demandasaurus in a number of ways, including the lack of excavation on the posterior surface of the caudal rib, the orientation of the neural spine, and the composition and morphology of the lateral lamina. In addition, the Isle of Wight vertebra possesses one potential autapomorphy: bifurcation of the elliptical fossa on the neural spine. However, because of the fragmentary nature of the material, a new name is not erected. Along with Demandasaurus and Histriasaurus boscarollii, this caudal vertebra indicates the presence of at least three European rebbachisaurid taxa and provides new anatomical information on this enigmatic clade of sauropod dinosaurs.     

First Lower Cretaceous record of Podocarpaceae wood associated with dinosaur remains from Patagonia,Neuquén Province,Argentina

The first Podocarpaceae wood record is described from the Mulichinco Formation (Valanginian, Lower Cretaceous), Neuquén Basin, Argentina. The specimen was directly associated with a middle caudal vertebra of a diplodocid sauropod dinosaur. A new species – Podocarpoxylon prumnopityoides – is proposed based on features that include the presence of abietinean wood type (tracheid radial pitting), plus podocarpoid (cupressoid type) and some dacrydioid (taxodioid type) cross-field pits, diffuse axial parenchyma and low rays. This combination of anatomical characters is comparable to both Prumnopitys and Podocarpus, whereas the type of pits in the cross-fields resembles some members of the extant Prumnopitys. This is the first unequivocal record of the Family Podocarpaceae in the Valanginian of South America and confirms the hypothesis that the divergence between the “Podocarpoid-Dacrydioid” and “Prumnopityoid” clades occurred earlier than the Early Cretaceous.     

New rebbachisaurid (Dinosauria: Sauropoda) material from the Wessex Formation (Barremian, Early Cretaceous), Isle of Wight, United Kingdom

Rebbachisauridae is a poorly understood clade of diplodocoid sauropod dinosaurs, currently known only from the Cretaceous of Africa, Europe and South America. European representatives are particularly rare and fragmentary. Here, we report an anterior caudal vertebra from the Barremian (Early Cretaceous) Wessex Formation of the Isle of Wight, off the southern coast of England. This specimen possesses several features known only in rebbachisaurids and shares two synapomorphies with the Afro-European taxa Demandasaurus darwini and Nigersaurus taqueti, both pertaining to the morphology of the neural spine. These features are the development of triangular lateral processes and the presence of an elliptical fossa on the lateral surface, bounded by the lateral lamina and postspinal rugosity. The Isle of Wight specimen also shares several features solely with Demandasaurus, indicating a close relationship with the Spanish taxon. These include the presence of a hyposphenal ridge, as well as an anteriorly excavated caudal rib that is restricted almost entirely to the neural arch. However, it differs from Demandasaurus in a number of ways, including the lack of excavation on the posterior surface of the caudal rib, the orientation of the neural spine, and the composition and morphology of the lateral lamina. In addition, the Isle of Wight vertebra possesses one potential autapomorphy: bifurcation of the elliptical fossa on the neural spine. However, because of the fragmentary nature of the material, a new name is not erected. Along with Demandasaurus and Histriasaurus boscarollii, this caudal vertebra indicates the presence of at least three European rebbachisaurid taxa and provides new anatomical information on this enigmatic clade of sauropod dinosaurs.     

A possible azhdarchid pterosaur (Pterosauria,Azhdarchidae) in the Durlston Formation (Early Cretaceous,Berriasian) of southern England

A new specimen of pterosaurian metacarpal IV from the Early Cretaceous (Berriasian) Durlston Formation of Dorset, southern England, closely resembles those of the Chinese dsungaripterid Dsungaripterus weii Young, 1964 and the Central Asian azhdarchid Azhdarcho lancicollis Nessov, 1984. However, the new specimen lacks the thickened bony wall typical of Dsungaripteridae and is therefore regarded as azhdarchoid. An mcIV with a markedly offset distal condyle with well-developed diaphyseal constriction behind the distal condyle and asymmetrical condylar margins may be an autapomorphy of Dsungaripteridae + Azhdarchoidea, while the same condition with bone thickening may typify Dsungaripteridae. The new specimen also provides osteological evidence supporting claims for large wing-spanned pterosaurs in the Berriasian of southern England based previously only on ichnological finds. The new specimen suggests a wingspan of between 2.9 and 3.7 m and represents the largest pterosaur from the Berriasian.     

A new Brachiosauridae Sauropod dinosaur from the lower Cretaceous of Europe (Soria Province,Spain)

A new dinosaur sauropod from the Golmayo Formation (upper Hauterivian-lower Barremian) in Soria province (Spain) is described as Soriatitan golmayensis gen. et sp. nov. The new material consists of one tooth, three dorsal vertebrae with ribs, a partial sacrum, five caudal centra, two caudal vertebral spines, one chevron, a humerus, an ulna, a radius, two partial ilia, two ischia, a fragment of pubis, and a partial femur. Cladistic analysis identified the material as belonging to Brachiosaruidae within Titanosauriformes. Sauropod material from the Golmayo Formation shares a diagnostic feature with Abydosaurus, Cedarosaurus, Tastavinsaurus and Venenosaurus including anteriorly deflected anterior–middle caudal neural spines and with Cedarosaurus a proximodistally straight lateral margin between the proximal head and the shaft of the humerus. Eight characters are potential autapomorphies in the sauropod from Spain, including the presence of a large rectangular ventral ridge below the preacetabular process of the ilium, the same length of the pubic and ischiadic blades in the ischium, and two lateral ridges in the lateral area of the deltopectoral crest of the humerus. The presence of Early Cretaceous brachiosarids in both, North America and Europe, give support to the hypothesis of a connection between the tectonic plates of these continents at some point during the Early Cretaceous.     

Neogyroporella? servaisi n. sp., nouvelle dasycladacee du Maastrichtien du Chiapas, sud-est du Mexique

Au Chiapas, sud-est du Mexique, la Formation Angostura d'âge Maastrichtien est riche en grands formanifères benthiques et en algues dasycladacées. Parmi celles-ci, nous avons reconnu une nouvelle forme, Neogyroporella? servaisi n. sp., qui se caractérise par un seul ordre de ramifications disposées en verticille et de type vésiculifère.In the State of Chiapas (SE Mexico), the Maastrichtian Angostura Formation is very rich in large benthic foraminifera and Dasycladaceae. We describe a new species. Neogyroporella? servaisi n. sp., which is characterized by having primary branches arranged in whorls of a vesicular type.     

Reappraisal of Fresnosaurus drescheri (Plesiosauria; Elasmosauridae) from the Maastrichtian Moreno Formation,California, USA

The elasmosaurid Fresnosaurus drescheri, Welles from the contact between the Tierra Loma/Marca members of the Moreno Formation (Maastrichtian), California, USA is reviewed. Most of the features included in Welles's original diagnosis are considered related only to the juvenile ontogenetic stage of the holotype and only specimen. The new diagnosis is based on diagnostic characters of the ilia, including long rectangular shaped sacral facets located in the dorsal part of the shaft, two gentle knobs in the shafts and unexpanded dorsal end. Additional material from the Moreno Formation (numbered under the same number as the F. drescheri holotype but not mentioned by Welles and therefore considered part of a different specimen) are described for the first time. The latter are referred to the aristonectine, being the first evidence of aristonectines from the North Hemisphere.     

New evidence for the possible occurrence of Tyrannosaurus in West Texas,and discussion of Maastrichtian tyrannosaurid dinosaurs from Big Bend National Park

Speculation regarding Tyrannosaurus in West Texas has been largely based upon a sub-adult tyrannosaurid maxilla from the Javelina Formation (Late Cretaceous–Maastrichtian) of Big Bend National Park. However, a very large anterior caudal vertebra, recently collected from the Javelina Formation, exhibits a morphology that can confidently be assigned to Tyrannosauridae and, because of its size, likely pertains to an adult Tyrannosaurus. The stratigraphic position of the specimen is closely bracketed by titanosaurid remains and further supports coexistence of these taxa. The stratigraphic position of the specimen possibly records one of the earliest occurrences of Tyrannosaurus. If so, Tyrannosaurus likely existed during roughly equivalent temporal intervals in disparate paleobiomes in both northern and southern late Maastrichtian faunal realms of North America.     

The earliest record of Asian Eusuchia from the Lower Cretaceous Khok Kruat Formation of northeastern Thailand

We describe remains of a new crocodyliform found from the Lower Cretaceous (Aptian) Khok Kruat Formation, northeastern Thailand. Remains consist of two caudal ends of mandibles, two rostral symphyseal parts of right rami of mandibles, a dorsal part of postorbital, a cranial end of squamosal and one osteoderm. Phylogenetic analyses supported inclusion of this crocodyliform into the Eusuchia as it shares several morphological characters with other eusuchians, such as a dorsocaudally oriented retroarticular process, smooth lateral surface of the caudoventral region of mandible, and a craniocaudally oriented ridge on the dorsal surface of retroarticular process. The shape of symphyseal region showed this crocodyliform had a longirostrine snout shape, which is uncommon in early eusuchians. Finding of this crocodyliform draws back the oldest record of Asian eusuchians, which was Tadzhikosuchus, approximately 30 million years and it is the only Mesozoic eusuchian found in East and Southeast Asia.     

A forefin of Leptonectes solei from the Lower Jurassic (Pliensbachian) of Dorset,UK

An incomplete forefin in the collections of the National Museum of Wales, Cardiff, is herein assigned to the rare leptonectid species, Leptonectes solei, known only from the west Dorset coast. It is only the third specimen of the species and is smaller than both the holotype and referred specimen. The new specimen is from the Lower Jurassic (lower Pliensbachian, Charmouth Mudstone Formation, Tragophylloceras ibex Ammonite Zone, Acanthopleuroceras valdani Ammonite Subzone) of Seatown, Dorset, UK. It confirms that all three species of Leptonectes were present in the Pliensbachian and expands the known diversity of ichthyosaurs for that time period. We show that isolated forefins of Leptonectes can be assigned to a species with a high degree of confidence.     

New lacewings (Insecta,Neuroptera, Osmylidae,Nymphidae) from the Lower Cretaceous Burmese amber and Crato Formation in Brazil

One new osmylid genus and species, Burmaleon magnificus, and one new nymphid genus and species Rafaelnymphes cratoensis are described, respectively based on inclusions in the Cretaceous Burmese amber and on a compression fossil from the Crato Formation in Brazil. The nymphid Araripenymphes seldeni, from the Crato Formation, is redescribed on the basis of a new specimen, showing possible sexual dimorphism in wing coloration, a feature extremely rare among the Neuroptera. In a recently published phylogenetic analysis of the family, the attribution to the fossil taxa (versus rejection) of the larval characters proper to the modern nymphids, has a crucial impact on the resolution of the phylogeny. The compression fossils currently attributed to the Nymphidae should be revised because their wing venation alone is not really sufficient for an accurate family attribution to Nymphidae rather than to another family of Neuroptera (viz. Osmylidae).     

A new sauropod dinosaur (Dinosauria,Sauropoda) from the late Early Cretaceous of the Ruyang Basin (central China)

A new long-necked sauropod dinosaur, Yunmenglong ruyangensis gen. et sp. nov., is erected on the basis of an incomplete skeleton from the late Early Cretaceous Haoling Formation of the Ruyang Basin, Henan Province. The characters of the anterior cervical vertebrae, the shape of the neural canal of the dorsal vertebra and the ball-shaped distal end of the neural spine of caudal vertebrae with coarse surfaces differ from other long-necked sauropod dinosaurs. The new genus has characters in common with both Euhelopus and Erketu; it represents the first long-necked sauropod dinosaur recorded from central China to date. The rod-like, well-developed epipophyses and the pleurocoels on the cervical vertebrae indicate that it may be close to Euhelopus, an observation also confirmed by a phylogenetic analysis, which shows that Erketu, Yunmenglong and Qiaowanlong form a clade, and are more derived than Euhelopus.     

A new ornithopod (Dinosauria; Ornithischia) from Antarctica

A new ornithopod dinosaur from Antarctica, Trinisaura santamartaensis n. gen. et n. sp. is diagnosed by a unique combination of characters that includes a scapula with a spike-like acromial process with a strong and sharp lateral crest and longer than other ornithopods, a humerus with a rudimentary deltopectoral crest represented as a thickening on the anterolateral margin of the humerus, and shaft strongly bowed laterally, and an ischium gently curved along its entire length. The holotype specimen comprises vertebral and appendicular elements. The presence of axially elongate distal caudal vertebrae, pubis with long prepubic and postpubic processes, as well as a femur with a distinct anterior trochanter, pendant 4th trochanter and shallow anterior intercondylar groove constitute a combination of characters present in the Late Cretaceous Patagonian Gasparinisaura, Anabisetia and Talenkahuen. The materials were found on the surface enclosed in a hard sandstone concretion collected near the Santa Marta Cove, James Ross Island, from the lower levels of the Snow Hill Island Formation (Campanian). This is the first ornithopod taxon identified from this unit, and the second ornithischian dinosaur, after the ankylosaur Antarctopelta oliveroi. However, other ornithopod reports from nearby localities of James Ross and Vega islands in outcrops of the overlying Lopez de Bertodano Formation suggest that this clade was widely represented in the Campanian and Maastrichtian of the James Ross Basin, Antarctic continent.     

A gigantic caenagnathid oviraptorosaurian (Dinosauria: Theropoda) from the Upper Cretaceous of the Gobi Desert,Mongolia

A large, isolated symphyseal region of fused dentaries of an oviraptorosaurian was found in the Upper Cretaceous Bayn Shire Formation at Tsagaan Teg in the Mongolian Gobi Desert. A phylogenetic analysis places this specimen within Caenagnathidae. This specimen is comparable in size and morphology to the gigantic caenagnathid Gigantoraptor erlianensis from the Iren Dabasu Formation in China and is likely closely related to it. The occurrence of the specimen with possible affinities to G. erlianensis in the Bayn Shire Formation is consistent with the hypothesized correlation between the Bayn Shire and Iren Dabasu formations based on the co-occurrences of vertebrate fossils, especially turtles.     

New Cretaceous Elcanidae from China and Myanmar (Insecta,Orthoptera)

A new species of Elcanidae (Orthoptera: Elcanoidea), Panorpidium yixianensis sp. nov., is described based on two new specimens from the Lower Cretaceous Yixian Formation of northeastern China. It differs from other species in forewing characters and spines on the hind tibiae. In addition, a new specimen Burmelcana sp., is described and figured based on an amber inclusion from the mid-Cretaceous Burmese (Myanmar) amber. P. yixianensis sp. nov. represents the first definite record of Elcanidae in the Early Cretaceous Jehol biota, and Panorpidium is the only genus of Ensifera to be found in the Early Cretaceous faunas of England, Russia and China.     

The oldest theropods from the Neuquén Basin: Predatory dinosaur diversity from the Bajada Colorada Formation (Lower Cretaceous: Berriasian–Valanginian), Neuquén,Argentina

Here, we describe new theropod materials (several isolated teeth, an axis, two caudal centra and a proximal left tibia) from the type locality of the Bajada Colorada Formation (Lower Cretaceous, Berriasian–Valanginian). Although fragmentary, the recovered material shows a diverse association of meat-eating dinosaurs for this poorly understood period of time. Three techniques were used to assess the phylogenetic position of the isolated teeth: multivariate (PCA), discriminant and phylogenetic analyses. The morphotypes 1, 2 and 3 (small non-recurved isolated crowns) were regarded as Theropoda indet., as our analyses failed to support a more precise classification. Two large almost complete ziphodont crowns, considered morphotype 4, were identified as belonging to megalosaurid tetanurans by phylogenetic, discriminant and multivariate analyses, thus likely representing the first record of this ancient family in South America, and the youngest worldwide. We refer the axis to a small abelisauroid ceratosaurian based on the following suite of characters; long and pointed epipophyses, a pneumatic foramen in the centrum, the invaginated spinopostzygapophyseal lamina, and the anteroposteriorly long, dorsally convex, and dorsally/posteriorly unexpanded neural spine. The caudal centra can be referred to a theropod, and tentatively to Abelisauroidea, suggesting that they may belong to the same taxon than that represented by the axis. The tibia lacks the incisura tibialis, presents a low, sharp and proximally positioned fibular crest, and has a deep lateral fossa, which is limited dorsally by a coarse, rounded in section and anteriorly directed crest. This combination of features allows to refer it to a large abelisaurid. The Bajada Colorada dinosaur record includes so far a small abelisauroid, a large abelisaurid, a probably medium to large megalosaurid tetanuran, diplodocid and dicraeosaurid sauropods. It shows some similarities with Middle and Upper Jurassic units in central Patagonia, Africa and Portugal, suggesting that no significant dinosaur faunal turnover took place through the Jurassic-Cretaceous event in the southern part of South America.     

An ichthyosaur (Reptilia: Ichthyosauria) specimen from the Lower Cretaceous (Berriasian) Spilsby Sandstone Formation of Nettleton,Lincolnshire, UK

A fragmentary ichthyosaur specimen collected in situ at Castle Top Quarry in Nettleton, Lincolnshire, UK from exposures of the Lower Cretaceous (Berriasian) Spilsby Sandstone Formation (Subcraspedites ?preplicomphalus Zone) is reported. In general, Early Cretaceous ichthyosaurs from the Berriasian to Barremian are poorly understood. Despite the fragmentary nature of the described specimen, it is the first ichthyosaur reported from this specific zone and adds to the literature another rare ichthyosaur from the Berriasian.     

First Valanginian Polacanthus foxii (Dinosauria,Ankylosauria) from England,from the Lower Cretaceous of Bexhill,Sussex

A new partial skeleton of the armoured ornithischian dinosaur Polacanthus found in the Wadhurst Clay Formation (Valanginian stage) of Bexhill, Sussex is the oldest recorded occurrence of this taxon. Previous discoveries suggested that at least two armoured ornithischians occur in the Wealden succession: Polacanthus, which was mostly restricted to the Barremian, and Hylaeosaurus, which was recorded as present only in the Valanginian. The new discovery extends the stratigraphic range of Polacanthus into the Valanginian. Although these two taxa appear to be closely similar anatomically, their osteology now suggests they are not synonymous. The new specimen includes the first known jugal as well as a comparatively rare polacanthid plate/spine (splate) which probably comes from the shoulder (pectoral) area of these animals.     

A new Late Cretaceous crocodyliform from the western margin of Gondwana (La Rioja Province,Argentina)

The Cretaceous witnessed the greatest diversity of Gondwanan notosuchian crocodyliforms, which displayed high levels of diversity and a notable array of specialized forms that developed in different ecological niches. Among this diversity, the advanced notosuchians are a clade of mid body sized forms which displays a remarkable abundance but is restricted to two lithological units from the Late Cretaceous of South America, the Adamantina Formation in southeastern Brazil and the Bajo de la Carpa Formation in Patagonia (Argentina). The only exceptions known so far were the Late Cretaceous Labidiosuchus from the Marilia Formation in Brazil and Yacarerani from the Cajones Formation in Bolivia. Herein we report a new Cretaceous crocodyliform, Llanosuchus tamaensis gen. nov. et sp. nov., found in the Los Llanos Formation (Campanian?) in northwestern Argentina (La Rioja Province). The small specimen includes well preserved fragments of the cranium and mandible with an estimated skull size of about 9 cm lengths. This crocodyliform shares several derived characters with Notosuchus terrestris from the Bajo de la Carpa Formation (Patagonia) and it was found in a weakly developed sandy paleosol profile formed in wet local conditions but in a region characterized by semi-arid climate and active eolian sedimentation. The presence of a new advanced notosuchian in the Cretaceous of western Gondwana, and its intermediate geographical region between the known South American species (Brazil, Argentina and Bolivia), has interesting implications, and adds another record of an advanced notosuchian in deposits with inferred warm climates and semi-arid paleoenvironments. Finally, Llanosuchus tamaensis supports a Late Cretaceous age for Los Llanos Formation with important geological implications for La Rioja Province.