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New Palaeontology refs - including Ornitholestes forelimbs




PHIL SENTER (2006). FORELIMB FUNCTION IN ORNITHOLESTES HERMANNI OSBORN (DINOSAURIA, THEROPODA) . Palaeontology 49: 1029-1034.


Abstract: Ornitholestes hermanni is a Late Jurassic theropod dinosaur from North America. This kinematic study of Ornitholestes uses manual manipulations of forelimb casts to determine range of motion. The manual phalanges of the O. hermanni holotype, previously unidentified, are here identified as phalanges I-1, I-2 (ungual), II-2 and II-3 (ungual). At all represented manual joints, hyperextensibility is small or absent, whereas flexion is strong, as in most other theropods. The elbow can be strongly flexed beyond a right angle. When data on range of forelimb motion in Ornitholestes are added to such data from other theropods, high elbow flexion is present in maniraptoriform coelurosaurs but not in basal theropods. Forelimb functions requiring strong elbow flexion (such as holding objects to the chest, or tucking the forearms in for their protection or to reduce wind resistance or heat loss) were therefore available to maniraptoriform coelurosaurs but not to basal theropods.



NADIA B. FRÖBISCH and JÖRG FRÖBISCH (2006) A NEW BASAL PTEROSAUR GENUS FROM THE UPPER TRIASSIC OF THE NORTHERN CALCAREOUS ALPS OF SWITZERLAND. Palaeontology 49: 1081-1090

Abstract: A lower jaw with multicusped teeth and a number of unique characteristics was discovered in an extensive exposure of the Upper Triassic Kössen Formation in the Northern Calcareous Alps. The ramus of the jaw is high and dominated by a row of large, oval foramina that lies parallel to the tooth row. In addition, the anterior portion of the dentary exhibits a large number of nutritive foramina and small pits, which might indicate an association with a soft tissue structure and/or the presence of a keratinous cover of that area during life. All elements of the jaw are thin-walled and hollow, possibly pneumatic. Two teeth are preserved within the dentary. One is tricuspid and the other bears four cuSPS. The teeth are noticeably small in comparison with the overall size of the ramus, being only one-third of the height of the ramus. The teeth show a strong similarity to those of the well-known basal pterosaur genus Eudimorphodon, whose jaw morphology, however, clearly differs from the specimen described in this study. The dentition and the pneumatic bone structure make an assignment to the Pterosauria plausible. Based on the great number of distinct morphological characters the specimen is described as Caviramus schesaplanensis gen. et sp. nov.




E. E. MAXWELL and M. W. CALDWELL (2006). A NEW GENUS OF ICHTHYOSAUR FROM THE LOWER CRETACEOUS OF WESTERN CANADA. 1043-1052


Abstract: A new fauna of Lower Cretaceous (Albian) ichthyosaurs, which includes at least one new genus and species, was recovered from deposits of the Loon River Formation at Hay River, Northwest Territories, Canada. All Cretaceous ichthyosaurs have been referred to a single genus, Platypterygius. The Loon River Formation material, however, does not satisfy the diagnosis for Platypterygius, and it is distinctive enough to warrant the erection of a new genus and species of ichthyosaur. Maiaspondylus lindoei gen. et sp. nov. is distinguished from other ichthyosaurs by an extensive overlapping contact of the jugal and the maxilla; marginal teeth with smooth crowns, fluted cementum, lingual curvature and implantation in a dental groove; and humerus with isomorphic proximal and distal ends, featuring three distal articular facets in which the medial articular facet is smaller than the lateral facets. The holotype and referred material is described here, and the relationship of Maiaspondylus to other ophthalmosaurs is discussed.