Morphological Abnormalities and Dwarfism in Maastrichtian Foraminifera from the Cárdenas Formation, Valles–San Luis Potosí Platform, Mexico: evidence of paleoenvironmental stress

Abstract

During the early Maastrichtian an assemblage rich in large foraminifera, mostly composed of orbitoidal foraminifera, developed in the shallow-water deposits of the Cárdenas Formation (Valles-San Luis Potosí Platform, Mexico). Among them, the most abundant is Lepidorbitoides minima, some of which display a morphologically abnormal test consisting of polyvalent forms, conical tests and budding, which could be induced by abrupt changes in environmental factors. The occurrence of the abnormalities preceded the demise of this species and of all the larger foraminiferal association in the upper part of the Gansserina gansseri Zone (early Maastrichtian). The abnormalities could be induced by environmental stress, probably related to interplay of different events such as increased terrigenous input and the transition to deeper facies due to Laramide tectonic instability before the K/P boundary.A late Maastrichtian community of dwarfed planktic foraminifera composed of Trinitella scotti Brönnimann, Plummerita reicheli Brönnimann, Rugoglobigerina cf. macrocephala Brönnimann, Rugoglobigerina hexacamerata Brönnimann, Heterohelix punctulata (Cushman), Pseudoguembelina costulata (Cushman), Pseudotextularia intermedia de Klasz, Globigerinelloides asperus Bolli, Guembelitria cretacea Cushman, Rugoglobigerina rugosa (Plummer), Rugotruncana sp., Globotruncanita stuarti (de Lapparent), and Globotruncana arca (Cushman) developed in the upper part of the sequence. This uncommon morphology could also be related to the highly stressed paleoenvironmental conditions related to global climatic change and local tectonic activity. Associated with this planktic assemblage is a deeper-water dwarfed benthic foraminiferal community composed of Gyroidinoides nitidus (Reuss), Coryphostoma incrassata (Reuss), Pseudouvigerina plummerae Cushman, P. cretacea Cushman, Bolivina cretosa Cushman, Planulina texana Cushman and Cibicides harperi (Sandidge).Keywords: Abnormal foraminifera tests, Lepidorbitoides minima, dwarfed planktic foraminfera, Maastrichtian, Cárdenas Formation, Valles-San Luis Potosí Platform. ResumenDurante el Maastrichtiano temprano una asociación rica en macroforaminíferos compuesta principalmente de formas orbitoidales, se desarrolló en los depósitos de agua somera de la Formación Cárdenas (Plataforma Valles-San Luis Potosí, México

Morphological abnormalities of planktonic foraminiferal tests in the SW Pacific Ocean over the last 550ky

“…The few reports of planktonic species displaying test malformations spans a wide range of time and are mostly derived from the fossil record (e.g. Coccioni and Luciani, 2006;Luciani et al 2010;Rossignol et al, 2011;Omaña et al, 2012;Weinkauf et al, 2014). Malformations and aberrant morphologies have been observed in extinct Cretaceous morphospecies from the Southern Mediterranean region (Verga and Premoli Silva, 2002;Coccioni and Luciani, 2006) and Mexico (Omaña et al, 2012), in middle Eocene subbottinids from Northern Italy (Luciani et al, 2010) and in the Miocene species Mutabella mirabilis from the tropical Pacific, Indian…”

“…Geslin et al, 2002;Le Cadre et al, 2003;Wall-Palmer et al, 2011;Haynert and Schönfeld, 2014), oxygen depletion (e.g. Debenay et al, 2009;Luciani et al, 2010;Geslin et al, 2014), increased terrigenous input (Omaña et al, 2012), nutrification (e.g. Rossignol et al, 2011) and hydrodynamic damages (Stouff et al, 1999;Geslin et al, 2000).…”

Blooms of aberrant planktic foraminifera across the K/Pg boundary in the Western Tethys: causes and evolutionary implications

“…80% of the total volume of Deccan Traps emissions) ended at or near the K/Pg boundary, spanning the last 280 Kyr of the Maastrichtian. Deccan-induced global warming and cooling episodes at the late Maastrichtian seem to be responsible for dwarfing episodes in some planktic foraminiferal species (Keller and Abramovich 2009; Omaña et al 2012; Petersen et al 2016), migrations (Olsson et al 2001), and regional assemblage changes (Keller 2003), however, without a significant decrease in global planktic foraminiferal diversity (Arenillas et al 2000a,b). After the K/Pg boundary, small species began to appear following a model of “explosive” adaptive radiation (Smit 1982; Brinkhuis and Zachariasse 1988; Arenillas et al 2002, 2004).…”

Marginal marine trace fossils from the Cárdenas Formation (Maastrichtian), Rayón municipality, San Luis Potosí, Central Mexico

“…Myers (1968) divided the Cárdenas Formation into three informal members (lower, middle, and upper) and proposed three biostratigraphic units based on its invertebrate body fossil assemblages (Durania ojanchalensis, Arcostrea aguilerae, and Tampsia floriformis Zones). The Cárdenas Formation overlies the El Abra (Myers, 1968;Omaña et al, 2012) and Tamasopo formations (Santamaría-Orozco et al, 1990;Omaña et al, 2012), and it is unconformably overlain by the Tabaco Formation (Myers, 1968;López-Ramos, 1980;Schafhauser et al, 2007). Our study area is located at Amoladeras, southwest of Rayón municipality, on the southeastern of San Luis Potosí ( Figure 1; 14Q 424779 E -2410072 N).…”

“…Biogenic structures in subaqueous regimes are primarily controlled by substrate consistency, sediment grain size, energy conditions, water turbidity and salinity, depositional rates, oxygenation levels, and temperature (Ekdale & Mason, 1988;MacEachern et al, 2012), and are considered good indicators of sedimentary environments (MacEachern et al, 2012). The Cárdenas Formation is a very rich fossiliferous unit and its diverse faunal assemblages have been studied by several authors, most of them focused on echinoderms (Marín-Ávila, 2012;Myers, 1968;Navarro-Moctezuma, 2004), corals (Navarro-Moctezuma, 2004;Baron-Szabo et al, 2006), brachiopods (Myers, 1968;Pérez-Martínez, 2010), foraminifers (Carrillo-Bravo, 1971;Caus et al, 2002;Omaña et al, 2008Omaña et al, , 2012, crustaceans (Vega et al, 1995), ostracods (Caus et al, 2002), rudists (Oviedo-García, 2005;Pons et al, 2013;Schafhauser et al, 2003), and ammonites (Ifrim et al, 2005). Previous works on ichnology of the Cárdenas Formation (Zimbrón-Uresti & Alvarado-Valdez, 2015;Zimbrón-Uresti, 2016) reported Thalassinoides, Skolitos, and Ophiomorpha from La Calzada locality, Ciudad del Maíz Municipality, San Luis Potosí State.…”