Taxonomy and bathymetric distribution of the outer neritic/upper bathyal ostracodes (Crustacea: Ostracoda) from the southernmost Brazilian continental margin

Abstract

Sixty-five ostracode species belonging to 41 genera and 17 families were recorded in the outer shelf and upper slope off Rio Grande do Sul and Santa Catarina states, southernmost Brazil, between 100 and 586 m water depth interval. The ostracode occurrences are hypothesized to be influenced by both, the coastal waters and the Antarctic Intermediate Water (AAIW). The taxonomy of some species of Bradleya Hornibrook, 1952, Legitimocythere Coles & Whatley, 1989 and Henryhowella Puri, 1957 previously described in the same study area is revised. Bradleya gaucha sp. nov., Legitimocythere megapotamica sp. nov., Apatihowella acelos sp. nov., Apatihowella capitulum sp. nov., Apatihowella besnardi sp. nov., Apatihowella convexa sp. nov., and Aversovalva tomcronini sp. nov. are herein proposed. Trachyleberis aorata Bergue & Coimbra, 2008 is reassigned to the genus Legitimocythere and Bradleya pseudonormani Ramos et al., 2009 has its diagnosis emended. Bythocypris praerenis Brandão, 2008 is considered a junior synonym of Bythocypris kyamos Whatley et al., 1998a. Apatihowella Jellinek & Swanson, 2003 and Legitimocythere species have well-defined bathymetric distributions and are potential paleoceanographic markers for the Quaternary in the Southern Brazilian Margin.

Climatically induced changes in late Quaternary bathyal ostracod assemblages of the Camamu Basin, Brazil

“…An analogous pattern has been observed in other oceanic regions as, for instance, in the Arctic Ocean, where major climatic transitions in the mid-to-late Quaternary are correlated to foraminifera and ostracods turnovers (Cronin et al 2014). Bergue et al (2017) discussed a possible correlation between the MIS and the occurrences of some ostracod species in bathyal regions off Brazil and southeast of the USA, based on the finding that Aversovalva tomcronini Bergue et al 2016, Bythocypris kyamos Whatley et al 1998 and Saida ionia are restricted to MIS 1. Occurrences of other species in the Campos Basin (Southeastern Brazilian Margin) also demonstrated paleoclimatic influence, particularly decreased diversity during MIS 2 (LGM) (Bergue et al 2017).…”

“…These asemblages are particularly prone to be influenced by changes in the thermocline depth, and most of their species have limited geographic occurrence. Examples: Aversovalva tomcronini, Bradleya gaucha Bergue et al 2016, Cytherella pleistocenica Bergue et al 2007, Eucythere macerata Coimbra 2008, Krithe coimbrai Do Carmo andSanguinetti 1999, and Krithe gnoma Do Carmo and Sanguinetti 1999.…”

Paleoenvironmental significance of Benthic Foraminifera and Ostracoda from the late Quaternary of the Ceará Basin, Brazilian Equatorial Margin

“…Mat.) characterizes a typical bathyal environment, as observed in previous studies (e.g., Dingle et al 1990, Bergue et al 2006, 2016, Brandão 2010, Yasuhara et al 2013, Maia et al 2021. This is the first study on deep-sea ostracods from the Brazilian Equatorial Margin, but the paucity of material prevents detailed comparison with other studies in the Brazilian Margin.…”

Provinciality of Ostracoda (Crustacea) in the Northeastern and Eastern Brazilian shelves based on neontological and paleontological analyses

“…The Argentinian Province (with two subprovinces in Brazilian territory) of Ramos (1998) added to the confirmation of a Transitional Zone and the delimitation of the new Brazilian Province, is supported on the 104 samples herein analyzed and on previous studies of the taxonomy and distribution of neritic ostracods along the Brazilian shelf, as follows: Coimbra & Ornellas (1989), Ramos (1994Ramos ( , 1996, Coimbra et al (1994Coimbra et al ( , 1995Coimbra et al ( , 1999Coimbra et al ( a,b, 2004, Fauth & Coimbra (1998), Coimbra & Fauth (2002), Coimbra & Carreño (2002), Bergue & Coimbra (2002), Coimbra & Carmo (2002), Machado & Drozinski, (2002), Coimbra & Bergue (2003), Aiello et al (2004), Ramos et al ( , 2012Ramos et al ( , 2014, Sartori & Coimbra (2010), Bergue et al (2016), and Luz & Coimbra (2015).…”

“…Their faunal survey inspired many other taxonomic and zoogeographical studies, which resulted in the description of taxa typical of warm or temperate waters and a better understanding of the distribution patterns of the Brazilian benthonic shelf ostracods (e.g. Purper & Ornellas, 1987a,b, 1989Coimbra & Ornellas, 1986Ramos, 1994Ramos, , 1996Coimbra et al, 1994Coimbra et al, , 1995Coimbra et al, , 1999aCoimbra et al, ,b, 2004Coimbra et al, , 2020Fauth & Coimbra, 1998;Carmo & Sanguinetti, 1999;Ramos et al, 1999Ramos et al, , 2004Ramos et al, , 2012Ramos et al, , 2014Coimbra & Fauth, 2002;Coimbra & Carreño, 2002;Coimbra & Carmo, 2002;Bergue & Coimbra, 2002;Machado & Drozinsnki, 2002;Coimbra & Bergue, 2003;Aiello et al, 2004;Machado et al, 2005;Luz & Coimbra, 2015;Bergue et al, 2016;Coimbra & Morais, 2016;Morais & Coimbra, 2019).…”