Taxonomy of limnic Ostracoda (Crustacea) from the Quiricó Formation, Lower Cretaceous, São Francisco basin, Minas Gerais State, Southeast Brazil

Abstract

The present work presents a detailed taxonomic study on Ostracoda from the Quiricó Formation, Areado Group, São Francisco Basin, Brazil. The samples were collected from three outcrops in the Minas Gerais State: Tereza Farm (João Pinheiro Municipality), and from the banks of the São José and Quiricó creeks (Presidente Olegário Municipality). Sixteen ostracode species were recovered: Harbinia alta, Harbinia aff. H. angulata, Harbinia aff. H. crepata, Harbinia aff. H. salitrensis, Harbinia symmetrica, Brasacypris fulfaroi, Brasacypris ovum, Cypridea conjugata, Cypridea hystrix, Cypridea infima, Cypridea jequiensis, Neuquenocypris (Protoneuquenocypris) antiqua, Penthesilenula martinsi, Penthesilenula pintoi new species, Alicenula longiformis new species, and Timiriasevia sanfranciscanensis new species. With the recovery of well-preserved specimens, it was possible to observe new characteristics in Brasacypris ovum, Cypridea conjugata, C. hystrix, and C. infima, and propose emendments to them. Additionally, three new species are described: Penthesilenula pintoi n. sp., Alicenula longiformis, n. sp., and Timiriasevia sanfranciscanensis n. sp. To date, the genus Timiriasevia had not been recorded in strata from Brazil. Also, Darwinula martinsi is reassigned to the genus Penthesilenula. Several species herein recorded are also found in other Brazilian continental basins, as well as in African and Argentinian basins, contributing to the knowledge of Brazilian Cretaceous continental deposits.

The genus Cypridea (Crustacea, Ostracoda) and the age of the Quiricó Formation, SE Brazil: a critical review

“…In the SE Brazil, Moura & Praça (1985) and Moura (1987) provided a biostratigraphic framework of the Lower Cretaceous non-marine sequence in the Campos Basin. Other studies on non-marine Cretaceous ostracods in Brazil have been published more recently, some dealing with Cypridea species, of which I highlight Dias-Brito et al (2001), Coimbra et al (2002), Do Carmo et al (2004, 2008, 2013, Sousa et al (2018), and Leite et al (2018). Poporat & Colin (2012) reviewed the Early Cretaceous ostracod biozonation of Brazil and western Africa.…”

“…Barbosa (1965), Barbosa et al (1970Barbosa et al ( , 1997 and Delicio et al (1998) registered some non-marine ostracods in the Quiricó Formation. More detailed analyses on this paleolacustrine unit of the Sanfranciscana Basin, however, were carried out by Do Carmo et al (2004) and Leite et al (2018). In the former, 15 species were identified from 11 outcrop samples in João Pinheiro and Carmo do Paranaíba municipalities, Minas Gerais State, although most species remained in open nomenclature, including Cypridea sp.…”

“…1 recorded in one sample as poorly preserved carapaces. Leite et al (2018) sampled three outcrops, one in João Pinheiro and the other two in the Presidente Olegário municipalities, Minas Gerais State. Although they analyzed 168 samples, recovered only 16 species, most of which were not previously registered by Do Carmo et al (2004).…”

“…Amaral et al (2019) did not consider the remaining 11 species of Do Carmo et al (2004), probably because they were left in open nomenclature. Although the manuscript of Amaral et al was submitted in June 2019 and published online in September of the same year, they were clearly unaware of the work of Leite et al (2018). Leite at al.…”

“…Although the manuscript of Amaral et al was submitted in June 2019 and published online in September of the same year, they were clearly unaware of the work of Leite et al (2018). Leite at al. (2018) identified four species of Cypridea: C. hystrix Krömmelbein, 1962, C. conjugata Krömmelbein & Weber, 1971, C. infima Krömmelbein & Weber, 1971, and C. jequiensis Krömmelbein and Weber, 1971.…”