A Middle-Late Devonian fish fauna from the Sierra de Perijá, western Venezuela, South America

Abstract

A new Devonian fossil fish fauna from the region of Caiio Colorado between the Rio Palmar and Rio Socuy, Sierra de Perijh, Venezuela, comes from two localities and several horizons within the Campo Chico Formation, dated on plants and spores as Givetian-Frasnian in age. Placoderms are most common, with the antiarch Bothriolepis perija n. sp., showing affinity with species from the Aztec fish fauna of Victoria Land, Antarctica. A second antiarch, Venezuelepis mingui n.g. nsp., is also closely related to an Antarctic species, which is reassigned to this new genus. Fragmentary remains of a phyllolepid placoderm show similarity to the genus Austrophyllolepis from southeastern Australia. Chondrichthyan spines are provisionally referred to the Antarctilamnidae, and acanthodian remains include spines of the widespread taxon Muchueracunthus. Osteichthyans are represented by osteolepid and dipnoan scales and teeth, and scales lacking cosmine which may belong to another major taxon. This fauna has provided the first Devonian record from South America of three major fish groups: antiarch and phyllolepid placoderms, and dipnoans. These are widely distributed on most other continents. Although invertebrates and plants from the same sequence closely resemble those of eastern North America, the endemic elements in the fish fauna indicate Gondwana affinities. Phyllolepid placoderms are common in Givetian-Frasnian strata of Australia and Antarctica, but are only known from the Famennian in the Northern Hemisphere. The new phyllolepid occurrence extends their range across the northern margin of Palaeozoic Gondwana. The age and affinities of this new fish fauna are consistent with a model of biotic dispersal between Gondwana and Euramerica at or near the Frasnian-Famennian boundary. A narrow marine barrier separating northern and southern continental landmasses is indicated, in contrast to the wide equatorial ocean for the Late Devonian postulated from palaeomagnetic data.Key words: Fishes, Placodermi, Chondrichthyes, Osteichthyes, Acanthodii, Devonian, Venezuela. ZusammenfassungEs wird eine neue devonische Fischfauna aus dem Gebiet zwischen Caiio Colorado und Rio Socuy, Sierra de Perija, beschrieben. Die Funde stammen aus zwei Lokalitaten und mehreren Horizonten innerhalb der Campo Chico Formation, die auf Grundlage von Untersuchungen der Pflanzen-und Sporenfunde dem Zeitabschnitt Givetium-Frasnium zugeordnet werden. Placodermen sind durch den Antiarchen Bothriolepis periju n. sp. haufig vertreten. Sie sind mit Arten der Aztec-Fischfauna von Viktoria Land, Antarktis, verwandt. Ein zweiter Antiarche, der Venezuelepis ningui n. g. n. sp. ist eng mit einer Spezies aus der Antarktis verwandt, die ebenfalls dieser neuen Gattung zugeschrieben wird. Fragmentarische Reste eines phyllolepiden Placodermen weisen Ahnlichkeiten mit der Gattung Austrophyllolepis aus dem Siidosten Australiens auf. Wirbel eines Chondrichthyer werden vorlaufig den Antarctilamnidae zugeschrieben. Acanthodir-Reste schlieBen das weitverbreitete Taxon Muchae...

Chapter 9

“…Early and Middle Devonian brachiopod associations of northern South America show common elements with southern North America and are included in the Eastern Americas Realm (Barrett, 1985) or Appalachian Province (Boucot, 1985). However, Devonian fossil fish from the Perijá and Floresta deposits indicate a connec-tion with Laurussia but still present elements in common with Gondwana (Burrow et al, 2003;Janvier & Villarroel, 2000;Young & Moody, 2002a).…”

“…The Cuche Formation correlates with the Frasnian age Campo Chico Formation (Harvey, 1999) at the serranía de Perijá (Colombia-Venezuela border). The Campo Chico Formation yields a Phyllolepid fish fauna composed of Gondwanan and Laurussian elements (Young & Moody, 2002a, 2002b.…”

Volume 1

“…The Cuche Formation correlates with the Frasnian age Campo Chico Formation (Harvey, 1999) at the serranía de Perijá (Colombia-Venezuela border). The Campo Chico Formation yields a Phyllolepid fish fauna composed of Gondwanan and Laurussian elements (Young & Moody, 2002a, 2002b.…”

“…Early and Middle Devonian brachiopod associations of northern South America show common elements with southern North America and are included in the Eastern Americas Realm (Barrett, 1985) or Appalachian Province (Boucot, 1985). However, Devonian fossil fish from the Perijá and Floresta deposits indicate a connec-tion with Laurussia but still present elements in common with Gondwana (Burrow et al, 2003;Janvier & Villarroel, 2000;Young & Moody, 2002a).…”

Formación Campo Chico, Una Increíble Ventana a La Flora Y Fauna Fósil Del Devónico (Givetiano–frasniano) en La Sierra De Perijá, Venezuela

“…y Young et al (2000), discutieron los descubrimientos de plantas y vertebrados devónicos en la Formación Campo Chico y sus posibles implicaciones para el contacto Gondwana-Euroamérica. Posteriormente Young y Moody (2002), publicaron una descripción detallada de los peces fósiles encontrados en dicha formación, y discutieron las consideraciones filogenéticas de dichos fósiles.…”