Tracking late jurassic ornithopods in the lusitanian basin of Portugal : Ichnotaxonomic implications

The Sociedade de História Natural in Torres Vedras, Portugal houses an extensive collection of as yet undescribed dinosaur tracks with ornithopod affinities. They have been collected from different Late Jurassic (Kimmeridgian-Tithonian) geological formations (Praia de Amoreira-Porto Novo, Alcobaça, Sobral, and Freixial) that outcrop along the Portuguese coast, and belong to two different sub-basins of the Lusitanian Basin (the Consolação and Turcifal sub-basins). Three main morphotypes can be distinguished on the basis of size, mesaxony and the morphology of the metatarsophalangeal pad impression. The minute to small-sized morphotype is similar to the Anomoepus-like tracks identified in other Late Jurassic areas. The small to medium-sized morphotype resembles the Late Jurassic-Early Cretaceous ichnotaxon Dinehichnus, already known in the Lusitanian Basin. Interestingly, these two morphotypes can be distinguished qualitatively (slightly different size, metatarsophalangeal pad impression and digit morphology) but are nevertheless difficult to discriminate by quantitatively analysing their length-width ratio and mesaxony. The third morphotype is considered a large ornithopod footprint belonging to the ichnofamily Iguanodontipodidae. This ichnofamily is typical for Cretaceous tracksites but the new material suggests that it might also be present in the Late Jurassic. The three morphotypes show a negative correlation between size and mesaxony, so the smaller tracks show the stronger mesaxony, and the larger ones weaker mesaxony. The Upper Jurassic ornithopod record from the Lusitanian Basin has yielded both small and medium-sized ornithopod remains, mainly iguanodontians such as dryosaurids and ankylopollexians, which are the main candidates to be the trackmakers

Costa, Alfredo Augusto Machado e

UID/HIS/04209/2013publishersversionpublishe

Between history and contemporaneous geology : revisiting a "classical" (geo) site from the Upper Cretaceous of Portugal

The history of geology intends to research biographies, ideas and controversies that have contributed to the epistemological building of knowledge, and to the products of fieldwork and laboratory investigation, and related written production on geosciences. A transversal research of all these elements allows revealing itineraries, outcrops and sites where pioneer studies have been done.Many of them still exist nowadays and are suitable for teaching and outreach activities of geoscientific literacy. An excellent example of this close link between history of geology and geoheritage can be explored in the “classical” outcrops of Salmanha (Figueira da Foz,West Central Portugal), where highly fossiliferous Upper Cretaceous carbonate units have been studied since the mid 19th century. Extensively described by Paul Choffat, from 1886 onwards, its stratigraphic sections and Cenomanian-Turonian faunas were major contributions for the scientific knowledge of that time, and can still be used as a source of information for modern workers and as an important resource for teaching and touristic activities

A mina de carvão do Cabo Mondego e a paleontologia portuguesa

Resumo de comunicação apresentada nas jornadas realizadas na Batalha - Porto de Mós, de 11 a 13 de Setembro de 201

Minas de carvão e pegadas de dinossáurios : o exemplo do Cabo Mondego

Resumo de comunicação apresentada nas jornadas realizadas na Batalha - Porto de Mós, de 11 a 13 de Setembro de 201

A mina de carvão do Cabo Mondego : 200 anos de exploração

Resumo de comunicação apresentada nas jornadas realizadas na Batalha - Porto de Mós, de 11 a 13 de Setembro de 201

Ichnological evidence of Megalosaurid Dinosaurs crossing Middle Jurassic tidal flats

A new dinosaur tracksite in the Vale de Meios quarry (Serra de Aire Formation, Bathonian, Portugal) preserves more than 700 theropod tracks. They are organized in at least 80 unidirectional trackways arranged in a bimodal orientation pattern (W/NW and E/SE). Quantitative and qualitative comparisons reveal that the large tridactyl, elongated and asymmetric tracks resemble the typical Late JurassicEarly Cretaceous Megalosauripus ichnogenus in all morphometric parameters. Few of the numerous tracks are preserved as elite tracks while the rest are preserved as different gradients of modified true tracks according to water content, erosive factors, radial fractures and internal overtrack formations. Taphonomical determinations are consistent with paleoenvironmental observations that indicate an inter-tidal flat located at the margin of a coastal barrier. The Megalosauripus tracks represent the oldest occurrence of this ichnotaxon and are attributed to large megalosaurid dinosaurs. Their occurrence in Vale de Meios tidal flat represents the unique paleoethological evidence of megalosaurids moving towards the lagoon, most likley during the low tide periods with feeding purposes