Sharks (Neoselachii) and palynomorphs from Mendoza (Argentina): new evidence of the Late Cretaceous Atlantic marine transgression
2013; Taylor & Francis; Volume: 38; Issue: 2 Linguagem: Inglês
10.1080/03115518.2014.849027
ISSN1752-0754
AutoresMercedes B. Prámparo, Alberto Luis Cione, Bernardo González Riga,
Tópico(s)Fish biology, ecology, and behavior
ResumoAbstractPrámparo, M.B., Cione, A.L. & Gonzalez Riga, B., 2013. Sharks (Neoselachii) and palynomorphs from Mendoza (Argentina): new evidence of the Late Cretaceous Atlantic marine transgression. Alcheringa 38, 000–000. ISSN 0311–5518.Neoselachian (modern shark) teeth and palynomorphs have been recovered from the Late Cretaceous Jagüel Formation in the Province of Mendoza, Argentina. The fossiliferous beds were deposited during the Atlantic transgression that covered northern Patagonia and other parts of South America from the Maastrichtian to the Danian. Teeth of several lamniform sharks are attributed to the anacoracid Squalicorax pristodontus and cf. Serratolamna serrata of indeterminate familial affinity. These taxa became extinct at the end of the Cretaceous and confirm the late Maastrichtian age previously assigned to the Jagüel Formation in this northwestern part of the Neuquén Basin. For the first time, the selachian faunas are described together with algae and dispersed organic matter assemblages (palynofacies), revealing new elements of the neritic biota leading up to the Cretaceous–Paleogene (K–Pg) mass extinction in South America. The palynoflora consists exclusively of the prasinophyte algae Tasmanites, Cymatiosphaera and Pterospermella, indicative of stratified saline waters. Dispersed organic components in the profile (mainly opaque equidimensional phytoclasts and prasinophytes) are consistent with an inner neritic environment, with evidence (a great variety of particle sizes, lath-shaped phytoclasts increasing slightly in number and decreasing number of marine components) of slightly more nearshore conditions towards the upper part of the profile. These marine biotas confirm the presence of an epeiric sea over northern Patagonia, which extended westwards to the volcanic arc on the western flank of the Andean Cordillera in Mendoza.Mercedes B. Prámparo [mprampar@mendoza-conicet.gov.ar], IANIGLA-CONICET, CCT-Mendoza. Avda. R. Leal s/n, Parque Gral. San Martín, (5500) Mendoza, Argentina; Alberto Luis Cione [acione@museo.fcnym.unlp.edu.ar], División Paleontología de Vertebrados. Museo de La Plata. 1900 La Plata, Argentina; Bernardo González Riga [bgonriga@mendoza-conicet.gov.ar] IANIGLA-CONICET, CCT, Mendoza. Avda. R. Leal s/n, Parque Gral. San Martín, (5500) and ICB, Universidad Nacional de Cuyo, Argentina. Received 28.5.2013, revised 17.9.2013, accepted 24.9.2013.现代鲨鱼Neoselachian 的牙齿和孢粉采自阿根廷Mendoza省晚白垩世Jagüel组。含化石地层沉积于大西洋海侵期间。该海侵从Maastrichtian阶至Danian阶期间覆盖Patagonia北部及南美其它地区。若干lamniform鲨鱼牙齿归属于anacoracid Squalicorax pristodontus和cf. Serratolamna serrate, 其科级亲缘关系不确定。这些物种灭绝于白垩纪末, 确证时代为Maastrichtian阶晚期, 而以前被认为是Neuquén盆地西南部的Jagüel组。通过首次对selachian动物群和藻类及分散的有机物质组合(孢粉相)的综合描述 , 揭示了近白垩纪 – 早第三纪(K -PG)生物大灭绝时南美浅海生物的新分子。孢粉植物群专门由prasinophyte藻类Tasmanites , Cymatiosphaera和Pterospermella 组成, 指示分层盐水水域。剖面中分散的有机成分(主要是不透明等维植物碎屑和藻类)与内浅海环境相一致, 剖面上半部分有证据(多种颗粒大小, 板条状植物碎屑数量略微增加和海洋分子数量的减少)指示稍近岸环境。这些海洋生物群证实了在Patagonia北部陆表海的存在, 它向西延伸到Mendoza安第斯山脉西侧的火山弧。Key words: Neoselachiishark teethPrasinophytesorganic matter assemblagesLate Cretaceoussouthern MendozaArgentina AcknowledgementsThe authors are indebted to Dr S. McLoughlin, V. Bowman and an anonymous reviewer, whose comments and critical observations considerably improved this contribution. Our work was partially supported by CONICET (PIP 713/09 to B. González Riga and M.B. Prámparo), Universidad Nacional de Cuyo (06/M044 to B. González Riga) and Agencia Nacional de Promoción Científica y Tecnológica (PICT 2006-913 to A.L. Cione). We are also grateful to the Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales (Mendoza) for their laboratory (M.A. Moschetti) and field support and to Rafael Bottero for his collaboration in the composition of Figure 1. The authors are grateful to Erik Marsh (USA) for reviewing the English version of the text.
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