We describe a well-preserved pelvis from the Maastrichtian S^anpetru Formation of the Hat¸ eg Basin in Romania. The fossil closely resembles the pelvis of Gargantuavis philoinos from the Ibero-Armorican Peninsula, but differs in a smaller size and a few morphological features. It constitutes the first record of Gargantuavis outside the Ibero-Armorican Island and is more complete than any of the previously known Gargantuavis pelves. The new fossil allows the recognition of characteristics previously unknown for Gargantuavis. These include the presence of large supratrochanteric processes, the absence of a widened midsection of the synsacrum (which indicates the absence of a glycogen body), and the absence of fusion between the pelvic bones at the level of the acetabulum. The latter two features suggest that Gargantuavis is not closely related to the Ornithurae and the taxon may even fall outside the Ornithothoraces, the clade including Enantiornithes and Ornithuromorpha. Recognition of Gargantuavis in the fauna of the Hat¸ eg Island is of particular significance, because various theropods have been described from the Upper Cretaceous of Romania. The Romanian pelvis is of similar size to Elopteryx nopcsai, which was described as avian and is based on hindlimb elements, and it also shows some similarities to the pelvis of the unusual theropod Balaur bondoc. The new fossil furthermore disproves the hypothesis that the flight capabilities of Gargantuavis were lost in an insular environment of the Ibero-Armorican Island, and raises the possibility that Gargantuavis, Elopteryx, and Balaur belong to a distinctive theropod clade of the Late Cretaceous European archipelago.
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RBINS Staff Publications 2018
Across the globe, there are millions of in-stream structures that fragment the world'’s river networks, acting as barriers that can impede the movements of fish. Designing effective solutions to accommodate fish communities requires information about the swimming abilities and behaviours of all species. This should account for different swimming modes, abilities, behaviours, and niches. We investigated the swimming speeds of nine migratory New Zealand species to assess both inter- and intraspecies variation. We then calculated maximum traversable speeds for culverts of a given length, based on the endurance abilities of our lowest performing species (Galaxias maculatus). Our findings reveal significant inter- and intraspecies variation in swimming speeds. Among the species studied, Galaxias brevipinnis, Galaxias argenteus, and Galaxias postvectis were the strongest swimmers. In contrast, Galaxias maculatus was one of the weakest swimmers. Body length positively correlated with Umax indicating that fish passage barriers select against the weakest swimming species, as well as smaller individuals within a species. Maximum water speeds in a culvert must be lower than 0.3 m s−-1, the previously assumed standard rule-of-thumb for New Zealand, to provide adequate passage for a high proportion of a weak-swimming indicator species (Galaxias maculatus). Synthesis and applications: . Previous maximum traversable water speeds for fish passage designs have been based on average swimming ability, but this approach only enables fish that are better than the average swimmers of their species to overcome barriers. This study highlights the importance of evidence-based designs for successful fish passage solutions to account for the ability of all fish. By considering differences between and within species, rather than assuming a “‘one-size-fits-all” ’ approach we can develop more effective passage solutions that better preserve fish communities.
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RBINS Staff Publications 2024
