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Brachyplatystom a promagdalena, new species, a fossil goliath catfish (Siluriformes: Pimelodidae) from the Miocene of Colombia, South America
Journal article   Open access

Brachyplatystom a promagdalena, new species, a fossil goliath catfish (Siluriformes: Pimelodidae) from the Miocene of Colombia, South America

John G. Lundberg
Neotropical Ichthyology, v 3(4), pp 597-605
01 Dec 2005
url
http://www.scielo.br/pdf/ni/v3n4/v3n4a17.pdfView
Published, Version of Record (VoR) Open
url
https://doi.org/10.1590/S1679-62252005000400017View
Published, Version of Record (VoR) Open

Abstract

ZOOLOGY
A fossil Weberian complex of a large pimelodid catfish from the middle Miocene La Venta fauna of central Colombia originally identified as Brachyplatystoma sp. is described as a new, extinct species. Brachyplatystoma promagdalena, new species, is diagnosed by three autapomorphic characters: fifth centrum with a massive midventral expansion containing deep cavities and heavy ridges; first and compound centra contribute to a pair of prominent anterolateral processes before the ventral ends of the ossa suspensoria; and compound centrum with an anteriorly concave low ridge crossing its ventral surface posterior to aortic canal foramen. Brachyplatystoma promagdalena is compared to modern congeneric species and placed in the subgenus Malacobagrus with B. filamentosum, B. capapretum and B. rousseauxii. This group is characterized by synapomorphies of the texture and form of the first vertebra; texture and form of the dorsal side of the fourth transverse process; and presence of a bony gas bladder platform on the ventral side of the fourth transverse process. Today Brachyplatystoma ranges widely across the lowland Orinoco and Amazon and some river basins of the Guianas. The genus does not occur west or north of the Andes or Venezuelan coastal ranges. The Miocene species of Brachyplatystoma signals the former large river and biotic connection between the paleo-Amazonas-Orinoco system and central Colombia, a region now drained by the río Magdalena. Other fossils of aquatic vertebrates from the La Venta fauna show this same biogeographic relationship.

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