Pistas fósiles y dubiofósiles del Ediacárico y Cámbrico del Anticlinal de Alcudia, Espa?a

摘要

The fossil record of the Ediacaran—Cambrian transition in Spain provides potentially useful information to understand this critical episode in the history of life on Earth. In the present work, new findings of trace fossils and dubiofossils are described from the upper Ediacaran and lowermost Cambrian of the Alcudian unit in the Alcudia Anticline, at the southern margin of the Central Iberian Zone (valle de Alcudia, Iberian Massif, Spain). Two new trace fossil sites are described from the Upper Alcudian subunit and assigned to the Fortunian stage (lower Cambrian, Terreneuvian series) and to the regional Lower Corduban substage. They contain examples of arthropod-like scratches ( Monomorphichnus lineatus ), small bilobed trails (similar to Archaeonassa ), an inclined burrow with spreite (may be a teichichnid), and long unbranched burrows with very fine transversal structure (probably the ventral surface of Psammichnites ). Torrowangea aff. rosei and possible body fossils of late Ediacaran age are described from the Lower Alcudian subunit, including a disc resembling a frond holdfast and a diamond-shaped complex structure with no known equivalents.