First record of the ichnogenus Phycodes in the Middle Ordovician of the Toledon Mounts (Central Iberian Zone, Spain)
Aasta | 2016 |
---|---|
Ajakiri | Boletín de la Real Sociedad Española de Historia Natural. Sección Geológica |
Köide | 110 |
Leheküljed | 8-23 |
Tüüp | artikkel ajakirjas |
Keel | hispaania |
Id | 24090 |
Abstrakt
Phycodes noha Mikuláš, a horizontal flabellate burrow system so far restricted to the lutitic facies of the Lower Ordovician of the Czech Republic and the Middle Ordovician of Portugal, is recorded for the first time in Spain. The Spanish specimens show a complete morphological transition from typical fan-shaped passages forming a compact subtriangular body in plan view, to rarer bilateral forms ending in fanlike arrangement. The studied material comes from the lower Oretanian shales (ca. basal middle Darriwilian) outcropping at the Cuesta de Valderuelo section, west of Navas de Estena (Ciudad Real province). The morphological study concluded that Phycodes canelensis, a composite form described from the lower Oretanian beds in Portugal, could be better considered as a junior synonym of P. noha. Its description is based on incomplete specimens lacking the generating tube and stuffed with faecal pellets (Tomaculum problematicum), only hypothetically produced by the tracemaker of Phycodes. The discovery of Phycodes noha in Spain increases the very low ichnodiversity of the Middle Ordovician shales from the Central Iberian Zone of the Iberian Massif.