Revision of the genus Protaxius (Decapoda, Axiidea, Axiidae), with description of a new species from the Lower Cretaceous of west-central Argentina

2021 ◽  
pp. 105053
Author(s):  
A. Mariel Andrada ◽  
Darío G. Lazo ◽  
Graciela S. Bressan ◽  
M. Beatriz Aguirre-Urreta
2020 ◽  
Vol 94 (4) ◽  
pp. 716-733
Author(s):  
Darío G. Lazo ◽  
Graciela S. Bressan ◽  
Ernesto Schwarz ◽  
Gonzalo D. Veiga

AbstractTwo new isocrinids are described from the Lower Cretaceous Agrio Formation of the Neuquén Basin, west-central Argentina. Isocrinus (Chladocrinus) covuncoensis new species is based on several beautifully preserved specimens from Valanginian beds of the Pilmatué Member. It is characterized by a small size, multiramose crown with six arm divisions, 240 arm tips, mostly isotomous branching, seven (or rarely eight) secundibrachials, smooth and stout column, short noditaxis, and pentalobate columnals. The species occurs in a 30 m thick interval of cross-bedded sandstones and mixed clastic-carbonate sediments that represent the migration of large, tidally influenced, subaqueous dunes developed in the offshore. Sudden burial of crinoids that dwelled on the dune toes and interdunes, possibly by the acceleration of the lee face migration, provided the exceptional preservation of specimens and thus this finding can be considered as a local crinoid Konservat Lagerstätte. Isocrinus (Chladocrinus) pehuenchensis new species is described from a single articulated specimen preserved in a silty calcareous concretion collected from a late Hauterivian concretion level of the Agua de la Mula Member. It is characterized by isotomous branching, eight or nine secundibrachials (IIBr), slender column ornamented with medial ridge of fine tubercles, interradius acuminated with fine tubercles on its tip, short noditaxis, and pentastellate columnals. It is associated with low-energy fall-out deposits in the offshore. The excellent state of preservation was due to an early cementation process by carbonate that enhanced lithification around the specimen.UUID: http://zoobank.org/4763ae70-9d0a-4015-b1c9-6a7ceeedfb1a


2014 ◽  
Vol 88 (6) ◽  
pp. 1222-1239 ◽  
Author(s):  
Cecilia S. Cataldo

The gastropod fauna of the Lower Cretaceous of the Argentinian Neuquén Basin contains three aporrhaid species.Protohemichenopus neuquensisCamacho, 1953 is the most abundant, longest-lived, and most geographically widespread of the aporrhaids of this basin, and its protoconch and early teleoconch whorls were unknown until now. The new speciesDimorphosoma weaverifeatures convex to subtly angular spire whorls with opisthocyrt collabral ribs that are more prominent towards the mid-whorl, a bicarinate last whorl with small rounded nodes on the adapical carina, a simple, falcate labral wing which is more or less rectangular proximally and tapering and curving towards its distal end, and a short, straight rostrum.Tylostoma jaworskiiWeaver, 1931 is now placed inHarpagodes, and other previous, scattered, coeval records of this genus in the basin are now recognized as part of this single species. It is believed that whereasH. jaworskiipreferred shallower-water carbonate settings of low to moderate energy,P. neuquensisandD. weaverifavored siliciclastic to mixed clastic-carbonate environments, in deeper waters. In spite of its endemic elements, this aporrhaid association depicts a predominantly Tethyan influence.


2013 ◽  
Vol 94 (1) ◽  
pp. 231-240 ◽  
Author(s):  
Ulyses F. J. Pardiñas ◽  
Pablo Teta ◽  
Damián Voglino ◽  
Fernando J. Fernández

2021 ◽  
pp. 1-9
Author(s):  
Mateo Daniel Monferran ◽  
Flaviana Jorge de Lima ◽  
Alexander Wilhelm Armin Kellner ◽  
Juliana Manso Sayão ◽  
Edilson Bezerra Santos Filho ◽  
...  

2017 ◽  
Vol 91 (4) ◽  
pp. 1200-1214 ◽  
Author(s):  
Peihong JIN ◽  
Teng MAO ◽  
Junling DONG ◽  
Zixi WANG ◽  
Mingxuan SUN ◽  
...  

Zootaxa ◽  
2016 ◽  
Vol 4200 (2) ◽  
pp. 327 ◽  
Author(s):  
PEDRO S. R. ROMANO

Pelomedusoides is the most diverse clade of side-necked turtles and there is an extensive fossil record (de Broin, 1988; Lapparent de Broin, 2000; Gaffney et al., 2006, 2011) that dates back at least to the Barremian (Lower Cretaceous) (Romano et al., 2014). Its large fossil record evidences a greater diversity in the past, particularly at the end of the Mesozoic, and exhibits a good sampling of species that are represented by skull material (Gaffney et al., 2006, 2011). As a consequence, the most complete and recent phylogenetic hypotheses for this clade (e.g. Romano et al., 2014; Cadena, 2015) are based on matrices comprising a great amount of cranial characters derived largely from Gaffney et al. (2006, 2011). In addition, it is well established that shell characters show a lot of phenotypic plasticity, even in the fossil species (Romano, 2008; Gaffney et al., 2006, 2011). In most cases it consequently is not justified to rely on “diagnostic features” of poorly informative shell-only material for describing a new species. Because of that, most authors remark new morphotypes in the literature when such aberrant specimens are recovered, but do not make any nomenclatural act by proposing a new yet poorly supported species (e.g. Romano et al., 2013; Ferreira & Langer, 2013; Menegazzo et al., 2015). Unfortunately, such a supposedly new bothremydid turtle (Pleurodira: Bothremydidae) from the Early Paleocene of Brazil was recently described based on poorly diagnostic remains (Carvalho et al., 2016; hereafter CGB, for the authors initials) and a correction of this unfounded nomenclatural act is required. In addition I present some comments on shell only material from Brazil in order to guide splitter-taxonomists to stop describing poorly preserved fossil specimens as new species. 


Zootaxa ◽  
2020 ◽  
Vol 4763 (4) ◽  
pp. 593-599
Author(s):  
CLAUDIA HEMP

A new Stenampyx, S. viridiflavum n. sp., is described from Tanzania. Stenampyx was monotypic and known from Central to West African forests. As with the genus Pseudotomias Hemp, the newly described species in Stenampyx shows a close relationship to the Central and East African forest fauna. 


Ameghiniana ◽  
2020 ◽  
Vol 57 (6) ◽  
Author(s):  
Maria E. P. Batista ◽  
Lutz Kunzmann ◽  
Artur A. Sá ◽  
Antônio Á. F. Saraiva ◽  
Maria I. B. Loiola

Sign in / Sign up

Export Citation Format

Share Document