Author 1. Pardo Cristian Author 2. Taboada Arturo Author 3. Taboada César Author 4. Pagani Alejandra

1. PENNSYLVANIAN BRACHIOPODS FROM EL IMPERIAL FORMATION (SAN
RAFAEL BASIN) MENDOZA, ARGENTINA: TAXONOMY, BIOSTRATIGRAPHY
AND BIO-CHRONOLOGICAL CORRELATION
PARDO, C.1, TABOADA, A.1, TABOADA, C.2, & PAGANI, A.2
1. Centro de investigación Esquel de Montaña y Estepa Patagónicas (CIEMEP) CONICET-UNPSJB, Roca 780, Esquel (U9200), Chubut, Argentina. Laboratorio de
Investigaciones en Evolución y Biodiversidad (LIEB), Facultad de Ciencias Naturales y Ciencias de la Salud (FCNyCS), Sede Esquel, Edificio de Aulas, km 16.5,
Esquel (U9200). pardocr22@gmail.com - taboadaart@gmail.com
2. CONICET-Museo Paleontológico Egidio Feruglio (MEF), Avenida Fontana N°140, Trelew (U9100GYO) Chubut, Argentina. ctaboada@mef.org.ar -
apagani@mef.org.ar

2.  Key localities where the El Imperial Formation cropping out1, Quebrada de La
Horqueta/Puesto Pantanito2, Cañón del Atuel3, Arroyo del Imperial4. Lower and upper
members are recognized at El Imperial Formation
 Intrabasinal bio-chronological correlation beetwen key sections.
Lower Member included Glacigenico and Cabecera del Cañón
Members of Cañón del Atuel
Modified from Taboada (2014)

3. TSAIII FAUNA
Moscovian
pTS FAUNA
early Late Bashkirian
Arroyo del Imperial Cañón del Atuel
Buxtonia cf. riojanae1-3
Streptorhynchus inaequiornatus4-6
Spiriferellina? sp.7
Septosyringothyris (Precosyringothyris)
feruglioi? 8-9
Septosyringothyris (Precosyringothyris) aff.
jaguelensis10-12
Saltospirifer guevarai13-15
Pericospira sp.16-18
Coolkilella aredesi1-4
Calytrixia piersoni5-7
Costatumulus sp.8-9
Oehlertella annae10-12
Orbiculoidea saltensis13-15
Septosyringothyris? sp.16-17
Argentiella cf. stappenbecki18
Taxonomic determination

4.  The Tivertonia-Streptorhynchus Biozone
can be subdivided in three
assemblages from base to top (pTS, T-
S and TSAIII)
 The set of index species that
characterized each assemblage are
discriminated including transitional
elements from each one to another
 Geographical distribution of each
assemblage is not homogeneous
across the central-western Argentina
 pTS and TSAIII are recognized in
Calingasta-Uspallata, Río Blanco and
San Rafael basins while T-S s.s. can be
only recognized in Paganzo and Río
Blanco basins
 A diachronic condition is clear
between the pTS and T-S faunas,
although any significant
biochronological discrimination could
be appreciated between T-S and
TSAIII groupings
Multivariated Statistical Analysis
Jaccard similarity index

5. Bio-chronostratigraphic correlation scheme of key litostratigraphic units and biozones CONCLUSIONS
 A new marine fauna
(TSAIII) at Cañón del
Atuel is reported
 Fossil-remains at
Arroyo del Imperial and
Quebrada de La
Horqueta belong to a
single fauna (pTS)
 Statistical analysis
support faunal
relationship between
the pTS (older) and
TSAIII (younger)
faunas to their relative
T - S fauna
 Bio-chronostratigraphic
scheme for the central-
western upper
Paleozoic Argentine
basins is updatedModified from Taboada (2014)