quinta-feira, novembro 05, 2009

Diversidade de pegadas do Jurássico Superior de Portugal

Portugal tem uma incrível diversidade de pegadas de dinossauro. Neste artigo publicado na revista Lethaia, divulgamos mais umas pegadas, que incluem várias de saurópode, terópode, estegossauro. Algumas têm marcas da pele ou mesmo da inserção da garra no dedo.
A de terópode é enorme, sendo uma das maiores pegadas de um dinossauro carnívoro do Jurássico.

O Mateus, J Milàn (2009) A diverse Upper Jurassic dinosaur ichnofauna from central-west Portugal Lethaia 10.1111/j.1502-3931.2009.00190.x:
Abstract: A newly discovered dinosaur track-assemblage from the Upper Jurassic Lourinhã Formation (Lusitanian Basin, central-west Portugal), comprises medium- to large-sized sauropod tracks with well-preserved impressions of soft tissue anatomy, stegosaur tracks and tracks from medium- to large-sized theropods. The 400-m-thick Lourinhã Formation consists of mostly aluvial sediments, deposited during the early rifting of the Atlantic Ocean in the Kimmeridgian and Tithonian. The stratigraphic succession shows several shifts between flood-plain mud and fluvial sands that favour preservation and fossilization of tracks. The studied track-assemblage is found preserved as natural casts on the underside of a thin bivalve-rich carbonate bed near the Tithonian–Kimmeridgian boundary. The diversity of the tracks from the new track assemblage is compared with similar faunas from the Upper Jurassic of Asturias, Spain and the Middle Jurassic Yorkshire Coast of England. The Portuguese record of Upper Jurassic dinosaur body fossils show close similarity to the track fauna from the Lourinhã Formation.


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