New dinosaur tracksites from the Middle Jurassic of Madagascar: ichnotaxonomical, behavioural and palaeoenvironmental implications

摘要: Abstract:  New dinosaur tracksites are described from the Bajocian–Bathonian Bemaraha Formation of western Madagascar. Two track-bearing surfaces can be followed over a distance at least 4 km, suggesting existence hitherto unrecognized megatracksite. The track assemblage is theropod dominated, but sauropod tracks also occur one site. Qualitative and quantitative analysis abundant material suggests that most, if not all, footprints attributable to single trackmaker referred Kayentapus isp. Although this ichnogenus, originally Lower Jurassic North America, has never been recorded Gondwana nor Middle Jurassic, morphology strongly attribution. Palaeogeographical, sedimentological ichnological data suggest formed in an intertidal supratidal setting where coastline influenced preferred walking direction animals.