Middle Ordovician (Darriwilian) linguliform and craniiform brachiopods from the Precordillera (Cuyania Terrane) of west-central Argentina

Abstract

Middle Ordovician lingulacean, trematid, and craniid brachiopods are described and illustrated for the first time from the uppermost part of San Juan Formation limestones of the Precordillera Basin, west-central Argentina. Sampled beds fall within theAhtiella argentinabrachiopod Zone, which, according to associated conodonts, is of early-mid Darriwilian age. The fauna consists of the linguloideansGlossella cuyanican. sp. andLingulasma? sp., the discinoideanTrematissp., the siphonotretidChilcatreta tubulatan. gen. n. sp., and a conical shell that is referred provisionally to the order Craniida. The linguliforms from the Cuyania (Precordillera) terrane, although still poorly known, display close similarities to those inhabiting low-to-intermediate latitude palaeocontinents, particularly Laurentia and Baltica, in accordance with evidence from rhynchonelliform brachiopods.

Unusual pitted Ordovician brachiopods from the East Baltic: the significance of coarsely pitted ornamentations in linguliforms

“…The pattern of coarse pitting in Foveola ivari is quite similar to that described in an unnamed species referred to Trematis from the Darriwilian of Argentina (Lavié & Benedetto , fig. 4.1–4.6), but the interior characters of that species are unknown.…”

“…indet. from the Darriwilian Precordillera (Cuyania Terrane), Argentina (Lavié & Benedetto , p. 1074); Obolidae, gen. et sp., Katian Chair of Kildare Limestone, County Kildare, Northern Ireland (McClean , p. 18); Foveola ivari sp. nov.…”

“…Some Darriwilian records referred to the discinoid Trematis, but lacking clear evidence of the distinctive ventral valve and preserved interiors (e.g. Lavié & Benedetto , fig. 4:1–6) may potentially also represent Foveola .…”

The strophomenide brachiopodAhtiellaÖpik in the Ordovician of Gondwana and the early history of the plectambonitoids

“…Depositional environments evolved from tidal flats, shoals, shallow subtidal settings, and restricted subtidal settings during the Cambrian−early Tremadocian, to open shelf settings by late Tremadocian-Darriwilian times (Cañas, 1999; Keller, 1999, 2012; Gómez and Astini, 2015). The carbonate succession referred to the San Juan Formation consists of ~350 m of burrowed skeletal wackestones and packstones capped by a 25−30 m thick interval of mid-outer ramp nodular limestones bearing a rich benthic fauna dominated by rhynchonelliform brachiopods and sponges, with trilobites, bryozoans, gastropods, crinoids, and linguliforms as secondary components (Carrera, 2003; Waisfeld et al, 2003; Sorrentino et al, 2009; Carrera and Ernst, 2010; Lavié and Benedetto, 2016) (Fig. 4).…”

First evidence of Lower–?Middle Ordovician (Floian–?Dapingian) brachiopods from the Peruvian Altiplano and their paleogeographical significance

“…The Celtic signature of the Puna–Famatinian assemblages was also supported by multivariate analysis (Benedetto, 2004; Benedetto et al, 2009). Faunal exchange among the Central Andean Basin (comprising the Altiplano/Puna, the Cordillera Oriental, and the Subandean Ranges), the Famatina Basin, and the Cuyania Terrane (Precordillera) likely started during the late Floian–Dapingian, slightly before the estimated time for docking of the Cuyania Terrane against Gondwana (Benedetto, 2004; Lavié and Benedetto, 2016, 2019). At that time, the separation of this terrane from the main continent could have been small enough to facilitate fluid faunal exchange (Benedetto, 2004; Lavié and Benedetto, 2016, 2019).…”