Formacion Campo Chico, una increible ventana a la flora y fauna fosil del Devonico (Givetiano-Frasniano) en la Sierra de Perija, Venezuela

In this study, we present a review of the stratigraphy and paleontological remains discovered during the last years in the Campo Chico Formation (Devonian), Sierra de Perija, Venezuela. The Campo Chico Formation is composed of grey/white, sandstones and conglomerates, interbedded with mudstones and some thin localized coals. The formation is interpreted as a marginal continental cycle with some marine influence towards the top. The thickness of the Campo Chico Formation is about 450 meters. Campo Chico Formation was dated based upon miospore assemblages as middle Givetian-middle Frasnian. The fossil fauna has provided the first Devonian record for Venezuela, of three major fish groups: antiarch, placoderms, and dipnoans, with endemic elements of Gondwana affinities. The floral fossil, dominated by lycophytes, is the most diverse of mid-late Devonian age from Gondwana, and closely resemble the eastern North America (Euramerica). Plotting the Sierra de Perija and New York floral occurrences onto the more recent palaeocontinental reconstructions for the Late Devonian, shows that the two localities were located in a warm temperate belt, between Gondwana and Euramerica. A narrow marine barrier separating the two continents is postulated for Campo Chico time.