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Ishigaki S.,Hayashibara Museum of Natural science | Lockley M.G.,University of Colorado at Denver
Historical Biology

Two theropod trackways with alternating long-short pace lengths and a didactyl theropod trackway were discovered from Ait Blal tracksite situated in central High Atlas Mountains, Morocco. They are described here together with other tridactyl and tetradactyl footprints. The track-bearing bed belongs to the Lower Jurassic (Pliensbachian) Aganane Formation. One of the theropod trackways with alternating pace lengths indicates locomotion by a limping dinosaur. In this trackway, the pathological irregularities in the morphology of right footprints suggest that the trackmaker had injured its right foot. Another trackway with alternating pace lengths suggests the accidental problem while walking of theropod trackmaker. The morphology of the didactyl theropod trackway may be attributable to a dromaeosaurid or dromaeosaurid-like trackmaker whose body fossil remains have not been reported from the Jurassic. If the trackmaker of the didactyl prints was a dromaeosaurid, the discovery supports the idea that dromaeosaurid dinosaurs had early origins and also are ancestral to birds. © 2010 Taylor & Francis. Source

Hone D.,University College Dublin | Tsuihiji T.,National Museum of Nature and Science | Watabe M.,Hayashibara Museum of Natural science | Tsogtbaatr K.,Mongolian Academy of science
Palaeogeography, Palaeoclimatology, Palaeoecology

Stomach contents preserved in fossil specimens provide direct evidence for the diet of extinct animals. Such exceptional fossils remain rare for predatory non-avian dinosaurs and each can add significantly to our understanding of trophic interactions between various taxa. Here we present evidence for the dromaeosaurid theropod Velociraptor scavenging on the carcass of an azhdarchid pterosaur, with a long bone of the pterosaur being found as gut contents of the dinosaur. Despite previous inferences of dromaeosaurs as hyper-predators, scavenging appears to have been an important part of their ecology. © 2012 Elsevier B.V. Source

Hone D.W.E.,Institute of Vertebrate Palaeontology and Palaeoanthropology | Watabe M.,Hayashibara Museum of Natural science
Acta Palaeontologica Polonica

Feeding traces for carnivorous theropod dinosaurs are typically rare but can provide important evidence of prey choice and mode of feeding. Here we report a humerus of the hadrosaurine Saurolophus which was heavily damaged from feeding attributed to the giant tyrannosaurine Tarbosaurus. The bone shows multiple bites made in three distinctive styles termed "punctures", "drag marks" and "bite-and-drag marks". The distribution of these bites suggest that the animal was actively selecting which biting style to use based on which part of the bone was being engaged. The lack of damage to the rest of the otherwise complete and articulated hadrosaur strongly implies that this was a scavenging event, the first reported for a tyrannosaurid, and not feeding at a kill site. Source

Belvedere M.,University of Padua | Dyke G.,University College Dublin | Hadri M.,University Mohamad V | Ishigaki S.,Hayashibara Museum of Natural science
Gondwana Research

We revise a famous set of fossil footprints that were described in the mid-1980s from the Middle Jurassic (Bathonian) of Morocco and that have often been considered to be an early record for Mesozoic birds. If correct, these tracks are the oldest records of birds from Gondwana and would have critical biogeographic and palaeobiological implications. The oldest skeletal fossils of avians are from the Late Jurassic of Germany (Laurasia). Thus, these important historical footprints are re-described and re-examined and new analyses are carried out on the additional tracks that also occur on the surface but that have never been described before. All the tracks on the surface show the same morphological characteristics, though their size is variable, and are compared here to known dinosaur and bird ichnotaxa. We used a laser scanner to generate a 3D digital model of the slab; this new approach allowed detailed descriptions of the specimens, the identification of new footprints on the surface, and the conclusion that they were likely left by non-avian dinosaurs (rather than birds). We show the potential of this new approach to the study of fossil footprints and trackways; high-resolution imaging and laser scanning add new information fundamental for a revision of the criteria for distinguishing between closely-related vertebrate groups, in this case dinosaurs and birds. © 2010 International Association for Gondwana Research. Source

Belvedere M.,University of Padua | Mietto P.,University of Padua | Ishigaki S.,Hayashibara Museum of Natural science
Geological Quarterly

The Late Jurassic Iouaridène tracksite has been studied for decades and is well-known for the reference trackway of Breviparopus taghbaloutensis. These siliciclastic flood-plain deposits bear probably more than 1500 tracks, and at least 21 trampled levels: they yield tracks of medium to very large sauropods, possible stegosaurs and theropods. The first accurate description of the footprint association made by biped trackmakers is proposed herein. More than six hundred footprints and more than a hundred trackways has been mapped and anaiysed; this led to the definition of four tridactyl and two tetradactyl morphotypes, mainly produced by small to very large theropods, while probable small ornithopod tracks are also present. The bipedal footprint association is dominated by medium-large theropods, which are also the most abundant type. The taxonomical attribution of the morphotypes is made difficult by the poor preservation of many specimens. Furthermore, for the most abundant theropod tracks, those with "megalosaurian" affinity, there is also a complex ichnotaxonomical situaiion, that makes the attributions yet more chalienging; however, it was possible to recognize the great affinity of the tridactyl specimens with the Megalosauripus tracks from the Iberian Peninsula and North America. Three-dimensional models were generated from the moulds of the best-preserved specimens to render a more detailed description and for easier access to the specimens. Source

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