Late Floian conodonts are recorded from a thin limestone lens intercalated in the lower part of the San José Formation
at the Carcel Puncco section (Inambari River), Eastern Cordillera of Peru. The conodont association
includes Gothodus costulatus LINDSTRÖM, Protopanderodus rectus (LINDSTRÖM), Drepanoistodus basiovalis
(SERGEEVA), Drepanoistodus forceps (LINDSTRÖM), Drepanodus arcuatus PANDER, Trapezognathus diprion (LINDSTRÖM),
Erraticodon patu COOPER, and Ansella cf. jemtlandica (LÖFGREN). This species association can be
assigned to the upper part of the well-documented Oepikodus evae Zone. It is the northernmost conodont record
of late Floian age in South America. This study updates the preliminary data presented in 2001 from this fossil
locality, and it has important consequences for the paleogeographic reconstruction of the Peruvian part of the
Central Andean Basin. In accordance with trilobites and brachiopods documented for the same strata, the conodont
association represents a relatively cold-shallow-water platform environment. The record of late Floian
conodonts towards the middle part of the San José Formation shows that the base of this unit in the studied section
is considerably older than other sections of the distribution area, where its lowermost part is dated as early
Darriwilian by the record of graptolites from the Undulograptus austrodentatus graptolite Zone. The diachronous
initiation of the marine sedimentation makes the lower part of the Carcel Puncco shales penecontemporaneous
with the volcanigenic rocks related with the Arequipa Massif, which transitionally underlie the San José
Formation in other places of the Altiplano and the Eastern Cordillera of Peru.
This research work has been funded by the AECI (Spanish
Agency for International Cooperation) and the Research Group
on Perigondwanan Precambrian and Paleozoic of the Universidad
Complutense (Madrid, Spain). José Cárdenas (Universidad
Nacional San Antonio Abad, Cuzco, Peru) and Dr. Enrique Díaz
Martínez (Spanish Geological Survey-IGME, Madrid) are
thanked for valuable assistance during the expeditions of 2002
and 2004. Guillermo L. Albanesi thanks especially the CONICET
and ANPCyT (FONCyT), Argentina, for continuous support of
his conodont studies. The referees of this paper, Svend Stouge
(Copenhagen, Denmark), Stig M. Bergström (Columbus, Ohio,
USA), and Yong Yi Zhen (Sydney, Australia), are greatly
acknowledged for their recommendations in order to improve the
final version. This paper is a contribution to the IGCP project 503.
Peer reviewed