A new Middle Devonian chitinozoan assemblage from northern Iberia

Chitinozoans were recovered from the Naranco, Huergas and Gustalapiedra formations of northern Spain, which yielded a diverse assemblage including 29 taxa in 9 named genera. The deposits are of early Givetian age, a time when Iberia was isolated from large continents as part of the Armorican Terrane Assemblage. The formations studied here consist of a large clastic unit interrupting carbonate deposition, with large limestone formations positioned above and below the formations analyzed here. This clastic unit includes the Kačák Event, an important global extinction event associated with anoxia in the marine realm. In this paper, the relatively well-preserved chitinozoan assemblage is described and considered from a biogeographical and stratigraphical perspective. The chitinozoan community was deposited in a short space of time and includes various taxa not previously known from the Middle Devonian, though the assemblage as a whole is attributable to the period. Only moderate similarity is seen with assemblages reported from Laurussia and Gondwana, with a slight bias towards the latter. This report adds to our knowledge of chitinozoan paleobiogeography and to other recent studies of Middle Devonian palynology in northern Iberia.