In 1987, a Sino-Canadian expedition known as the Dinosaur Project (China – Canada – Alberta – Ex Terra) discovered a large theropod skeleton in the Upper Jurassic Shishugou Formation of the Junggar Basin in northwestern China. The well-preserved skeleton lacks much of the tail and most of the arms, but is otherwise nearly complete. The new genus and species, Sinraptor dongi, represents a poorly understood stage of theropod evolution, even though a related form, Megalosaurus, was the first dinosaur described and named (by W. Buckland in 1824). Sinraptor has a large pneumatopore in the jugal, a pronounced postorbital rugosity, a relatively long intertemporal bar in which the postorbital appears very short in lateral aspect, and a pneumatic palatine. It is more advanced than Piatnitzkysaurus from Argentina, less derived than Allosaurus, and shows its strongest similarities to Yangchuanosaurus. The preorbital skull length of Sinraptor is relatively longer than in Yangchuanosaurus, but the skull is relatively lower. A specimen from Sichuan recently described as "Yangchuanosaurus" hepingensis represents a second species of Sinraptor. Sinraptor and Yangchuanosaurus are united in a new family of theropods, the Sinraptoridae.

MicroRNAs are well known to mediate translational repression and mRNA degradation in the cytoplasm. Various microRNAs have also been detected in membrane-compartmentalized organelles, but the functional significance has remained elusive. Here we report that miR-1, a microRNA specifically induced during myogenesis, efficiently enters the mitochondria where it unexpectedly stimulates, rather than represses, the translation of specific mitochondrial genome-encoded transcripts. We show that this positive effect requires specific miR:mRNA base-pairing and Ago2, but not its functional partner GW182, which is excluded from the mitochondria. We provide evidence for the direct action of Ago2 in mitochondrial translation by CLIP-seq, functional rescue with mitochondria-targeted Ago2, and selective inhibition of the microRNA machinery in the cytoplasm. These findings unveil a positive function of microRNA in mitochondrial translation and suggest a highly coordinated myogenic program via miR-1 mediated translational stimulation in the mitochondria and repression in the cytoplasm.

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A new, well-preserved specimen of Troodon fomosus is the first to reveal the internal anatomy of the lower part of the braincase. In addition to providing new information on the brain of this highly encephalized dinosaur, the uncrushed bones clear up anatomical details left obscure by earlier studies. Computerized tomography (CT) scans reveal the nature of the inner ear and the course of the pneumatic ducts diverging from the middle ear. Evidence is presented to show that four of the five periotic pneumatic systems found in bird skulls are present in Troodon. The anterior tympanic recess is the most elaborate system, and diverticula from each side extend anteriorly, dorsally and, posteriorly from the middle ear. The posterior tympanic recess is located within the paroccipital process and the basioccipital, but the pneumatopore posterolateral to the stapedial recess is secondarily closed. The dorsal periotic sinus is represented by a smooth-surfaced concavity on the lateral surface of the prootic. The position of a pneumatic recess in this region is demonstrated by the presence of a pneumatopore in the quadrate. Diverticula from the anterior and posterior tympanic recesses are connected within braincase bones, and a possible pneumatopore in the prootic may connect these to the dorsal tympanic recess. The pneumatic condition of the troodontid articular is unknown. Contralateral connections of the sinus systems have been used to argue for a close relationship between birds and crocodiles, but their presence in this specimen suggests that they appeared more than once in archosaurs or that they are plesiomorphic for crocodiles, dinosaurs, and birds. Cranial pneumaticity cannot be used by itself to resolve the interrelationships of crocodiles, theropods, and birds, but other characters suggest derivation of birds from theropods.Un nouveau spkcimen, bien prkservk, de Troodon fomosus est le premier i rkvkler l'anatomie interne de la partie infkrieure de la boite crinienne. En plus d'apporter de nouveaux enseignements sur le cerveau de ce dinosaure hautement enckphalique, les os complete divulguent clairement des dktails anatomiques que les ktudes antkrieures n'avaient pas r h s s i h klucider. L'examen des balayages CT (tomographie assistke par ordinateur) diwlgue la constitution de l'oreille interne, et indique en outre que le track des canaux pneumatiques diffkre de celui de l'oreille moyenne. Les observations dCmontrent que quatre des cinq systkmes pneumatiques periotiques trouvks dans les crines des oiseaux sont prksents dans Troodon. C'est la cavitk antkrieure du tympan qui reprksente le systkme le plus sophistiquk, et les diverticules de chaque c6tk s'ktendent vers l'avant, dorsalement et postkrieurement en partant de l'oreille moyenne. La cavitk postkrieure du tympan est localiske a l'intkrieur de l'apophyse paroccipitale et du basioccipital, mais la cavitk entre le pneumatopore postkrolatkral et stapkdial est secondairement fermke. Le sinus pkriotique dorsal est represent6 par une concavitk h surface lisse creusk...

A skull and partial skeleton of a new genus and species, Monolophosaurus jiangi n.gen., n.sp., of large theropod has been recovered from the Middle Jurassic beds in the Junggar Basin of Xinjiang, China. The most striking characteristic is a crest, formed primarily by the nasal and lacrimal bones, on the midline of the skull. Several foramina connect the hollow interior of the crest with the antorbital fossa. The function of the crest is unknown, although it most likely was used for visual recognition by other members of the same species. It is difficult to make a precise taxonomic assignment in the absence of information on the appendicular skeleton, but it appears to be more closely related to Allosaurus than to other megalosaur grade theropods.

Nearly all of the large-bodied predators (>2.5 tons) on northern continents during the Late Cretaceous were tyrannosaurid dinosaurs. We show that their most conspicuous functional specializations--a proportionately large skull, incisiform premaxillary teeth, expanded jaw-closing musculature, diminutive forelimbs, and hindlimbs with cursorial proportions--were present in a new, small-bodied, basal tyrannosauroid from Lower Cretaceous rocks in northeastern China. These specializations, which were later scaled up in Late Cretaceous tyrannosaurids with body masses approaching 100 times greater, drove the most dominant radiation of macropredators of the Mesozoic.

The gene encoding PTEN is one of the most frequently mutated tumor suppressor-encoding genes in human cancer. While PTEN's function in tumor suppression is well established, its relationship to anti-microbial immunity remains unknown. Here we found a pivotal role for PTEN in the induction of type I interferon, the hallmark of antiviral innate immunity, that was independent of the pathway of the kinases PI(3)K and Akt. PTEN controlled the import of IRF3, a master transcription factor responsible for IFN-β production, into the nucleus. We further identified a PTEN-controlled negative phosphorylation site at Ser97 of IRF3 and found that release from this negative regulation via the phosphatase activity of PTEN was essential for the activation of IRF3 and its import into the nucleus. Our study identifies crosstalk between PTEN and IRF3 in tumor suppression and innate immunity.

An evolutionary trend of decreasing size is present along the line to birds in coelurosaurian theropod evolution, but size increases are seen in many coelurosaurian subgroups, in which large forms are less bird-like. Here we report on a new non-avian dinosaur, Gigantoraptor erlianensis, gen. et sp. nov., from the Late Cretaceous Iren Dabasu Formation of Nei Mongol, China. Although it has a body mass of about 1,400 kg, a phylogenetic analysis positions this new taxon within the Oviraptorosauria, a group of small, feathered theropods rarely exceeding 40 kg in body mass. A histological analysis suggests that Gigantoraptor gained this size by a growth rate considerably faster than large North American tyrannosaurs such as Albertosaurus and Gorgosaurus. Gigantoraptor possesses several salient features previously unknown in any other dinosaur and its hind limb bone scaling and proportions are significantly different from those of other coelurosaurs, thus increasing the morphological diversity among dinosaurs. Most significantly, the gigantic Gigantoraptor shows many bird-like features absent in its smaller oviraptorosaurian relatives, unlike the evolutionary trend seen in many other coelurosaurian subgroups.