Skeletons

Carcharodontosaurs were the largest predatory dinosaurs, and their early evolutionary history seems to be more intricate than was previously thought. Until recently, carcharodontosaurs were restricted to a group of large theropods inhabiting the Late Cretaceous Gondwanan land masses, but in the last few years Laurasian evidence has been causing a reevaluation of their initial diversification. Here we describe an almost complete and exquisitely preserved skeleton of a medium-sized (roughly six metres long) theropod from the Lower Cretaceous series (Barremian stage) Konservat-Lagerstätte of Las Hoyas in Cuenca, Spain. Cladistic analysis supports the idea that the new taxon Concavenator corcovatus is a primitive member of Carcharodontosauria, exhibiting two unusual features: elongation of the neurapophyses of two presacral vertebrae forming a pointed, hump-like structure and a series of small bumps on the ulna. We think that these bumps are homologous to quill knobs present on some modern birds; the knobs are related to the insertion area of follicular ligaments that anchor the roots of the flight feathers (remiges) to the arm. We propose that Concavenator has integumentary follicular structures inserted on the ulna, as in modern birds. Because scales do not have follicles, we consider the structures anchored to the Concavenator arms to be non-scale skin appendages homologous to the feathers of modern birds. If this is true, then the phylogenetic bracket for the presence of non-scale skin structures homologous to feathers in theropod dinosaurs would be extended to the Neotetanurae, enlarging the scope for explaining the origin of feathers in theropods.

In this work we present Lithium, a pure Java structured parallel programming environment based on skeletons (common, reusable and efficient parallelism exploitation patterns). Lithium is implemented as a Java package and represents both the first skeleton based programming environment in Java and the first complete skeleton based Java environment exploiting macro-data flow implementation techniques. Lithium supports a set of user code optimizations which are based on skeleton rewriting techniques. These optimizations improve both absolute performance and resource usage with respect to original user code. Parallel programs developed using the library run on any network of workstations provided the workstations support plain JRE. The paper describes the library implementation, outlines the optimization techniques used and eventually presents the performance results obtained on both synthetic and real applications.

The transition from fishes to tetrapods was one of the most dramatic events in the evolution of vertebrates, but many pivotal fossils are incomplete, resulting in gaps in the data that are used for phylogenetic reconstruction. Here we present new observations from the most complete, acid-prepared Devonian tetrapodomorph fish yet discovered, Gogonasus1,2, which was previously placed just crownward of Kenichthys and rhizodontids3,4, the most primitive taxa on the tetrapod lineage. Unexpectedly, Gogonasus shows a mosaic of plesiomorphic and derived tetrapod-like features.Whereas the braincase and dermal cranial skeleton exhibit generalized morphologies with respect to Eusthenopteron5 or Panderichthys6, taxa that are traditionally considered to be phyletically close to tetrapods7,8, the presence of a deeply invaginated, wide spiracle, advanced internal spiracular architecture and nearhorizontal hyomandibula are specialized features that are absent from Eusthenopteron9. Furthermore, the pectoral fin skeleton of Gogonasus shares several features with that of Tiktaalik, the most tetrapod-like fish10. A new phylogenetic analysis places Gogonasus crownward of Eusthenopteron as the sister taxon to the Elpistostegalia. Aspects of the basic tetrapod limb skeleton and middle ear architecture can now be traced further back within the tetrapodomorph radiation.

Akkasdagi is a new vertebrate locality from Central Anatolia, Turkey, deted to middle Turolian ( MN 12). Rich bone pockets are included in the upper horizon of a tuff layer dated to 7.1. Ma. Hipparion remains are particularly abundant. on the basis od skeletons, four different species were recognized in Akkasdagi hipparions sample: 1) H. dietrichi, medium -to large-sized with long ans slender limb bones; 2) H. moldavicum, small-to-medium-sized with long ans slender limb bones; 3) H. brachypus, large-sized with short and robust limb bones; and 4) H.cf. longipes, very large-sized form with very long slender linb bones. The phylogenetic relationship of the Akkasdagi hipparions with other Eurasian late Miocene hipparions is discussed, and we also analyse biostratigraphic and palaeobiogeographic distribution of the determindes species in correlation with the available biochronologic, radio-metric and magnetostratigraphic data.

Describes superb 3D complete spoecimens of Latocamurus coulthardi, n. gen. n. sp., a basal camuropiscid arthrodire from Gogo, showing nasal capsule features with parasphenoid stil lattached to ethmoid bone. Describes terminalis nerve 0 for the firtst tiime in placoderms..

A new genus and species of Pachypleurosauria, Dianopachysaurus dingi, gen. et sp. nov., from a recently discovered Middle Triassic Lagerstätte in the Anisian Guanling Formation of Yunnan Province is described. The monophyly of Pachypleurosauria, including all potential Chinese pachypleurosaurs in this study, is supported by the rigorous cladistic analysis conducted here. Phylogenetic relationships of Chinese pachypleurosaurs are clarified. Wumengosaurus occupies the most basal position within Pachypleurosauria. Keichousaurus and Dianopachysaurus form the monophyletic Keichousauridae that is the sister group of all European pachypleurosaurs. Our cladistic analysis also supports a previously proposed paleobiogeographic hypothesis of an eastern Tethyan origin of pachypleurosaurs and their migration into the western Tethyan faunal province. The existence of a long ghost lineage as required by the paleobiogeographic hypothesis is greatly shortened by the discovery of Dianopachysaurus.

Résumé/Abstract The Dupont collections curated at the Royal Belgian Institute of Natural Sciences contain a large bone assemblage from Chamber B, horizon 4 of the third cave of Goyet (Belgium). This assemblage dates from the Weichselian (AMS date: 35.470+ 780-710 years BP). Ninety eight percent of the remains are from Ursus spelaeus. The presence of several skeletons and articulated body parts, and the low frequency of gnawing traces and charriage-à-sec indicate that the carcasses were only slightly disturbed. Based on the ...

... Exceptional soft-tissue preservation in a theropod dinosaur from Italy. Cristiano Dal Sasso 1 & Marco Signore 2, 3. ... Scipionyx represents a new maniraptoriform theropod. Its discovery is remarkable considering also the scarcity of juvenile theropod dinosaurs in the fossil record. ...