New bivalve genus from the Early Jurassic of Neuquén Basin, Argentina, and its bearing on the Cuspidariidae (Poromyida) fossil record

2018 ◽  
Vol 93 (1) ◽  
pp. 25-36
Author(s):  
Susana E. Damborenea

AbstractThe new endemic genus Neuquemya, from Pliensbachian deposits in west-central Argentina, is here described and tentatively referred to the Cuspidariidae on account of its shell characters. The new species Neuquemya leanzaorum has a thin, inflated shell, rounded anteriorly and rostrate posteriorly, with a narrow posterodorsal gape and opisthogyrous umbones. The hinge region bears small cardinal tubercles. The shell is ornamented by commarginal (anterior) and radial (posterior) sculpture, whereas the rostrum is smooth. The general and detailed characters of the shell are thus very similar to those of living cuspidariids. Cuspidariids are extremely specialized bivalves with special features related to their carnivorous habit. Their fossil record is scarce, and their phylogeny is poorly understood. Because a few key shell characters and all soft body features of the new genus are unavailable, the alternative possibility that his taxon could be a remarkable example of a homoeomorphic shell cannot be dismissed. If actually a cuspidariid, Neuquemya n. gen. becomes the oldest known member of the family ca. 100 Myr older than the Late Cretaceous records unequivocally accepted and supports the argument that the origin of the group is much older than its known fossil record. The possible relationships of the new genus with other poorly known Mesozoic genera are discussed. Although septibranchs in general and cuspidariids in particular are now conspicuous elements of deep-sea faunas, this new genus inhabited nearshore environments of the Neuquén Basin.UUID: http://zoobank.org/8adbd45b-c9c6-4f57-bcfc-c13e5f9182eb

2015 ◽  
Vol 89 (2) ◽  
pp. 331-345 ◽  
Author(s):  
S. Mariel Ferrari ◽  
Susana E. Damborenea ◽  
Miguel O. Manceñido ◽  
Miguel Griffin

AbstractTrochotomidae is a small but distinctive extinct family of pleurotomarioidean gastropods characterized by trochiform shells with an elliptical trema. Two new species of trochotomids are described from Pliensbachian deposits in the Neuquén Basin, Argentina. The new genus-group namePlacotomais proposed to replace the pre-occupied nameDiscotomaHaber non Mulsant. The record ofTrochotoma(Trochotoma)protonotialisnew species andTrochotoma(Placotoma)neuquensisnew species in the early Jurassic of Argentina extends the paleobiogeographical distribution of the genus (and the family) to the Southern Hemisphere. The new taxa reported here represent a component of the pleurotomarioidean adaptive radiation that took place in the Tethyan region during the earliest Jurassic. They are related to local patch coral reefs of shallow, open-marine paleoenvironments, agreeing with the known habitat of most species of this family. The group was well represented in the Tethyan region during the Mesozoic, especially during the Jurassic, and the new species represent its southernmost occurrence.


2021 ◽  
Vol 740 ◽  
Author(s):  
Álvaro García-Herrero ◽  
Patricia Esquete ◽  
Marina R. Cunha

The Tanaidacea are ubiquitous and amongst the most abundant taxa in the deep sea. However, their diversity in submarine canyons remains largely unknown. Here, two new species and a new genus of Paratanaoidea are described. Paranarthrura cousteaui sp. nov. is distinguished by the combination of the following characters: post-cheliped sclerites not fused, presence of one seta in the maxilliped endite, one long midventral seta in cheliped, one penicillate seta in the basis of pereopods 4–6, uropod endopod bi-articulated and uropod exopod shorter than endopod article 1. This species was found at the upper reaches of three Portuguese canyons, Cascais, Setúbal and Nazaré Canyons, and the adjacent open slope, between 897 and 1001 m water depths. Tirana vallis gen. et sp. nov. presents a combination of the characters that define the other two genera of Paranarthrurellidae, Paranarthrurella and Armatognathia, but also unique characters within the family: the antenna, cheliped and uropod are more elongate than the rest of the species; the pereopods 4–6 carpus spines reach at least half of the length of the propodus and the propodus of pereopods 4–6 have ramified subdistal spines. This species was found at the middle reaches of Setúbal Canyon (3214–3219 m water depth).


2010 ◽  
Vol 84 (2) ◽  
pp. 197-215 ◽  
Author(s):  
Craig S. Scott

Cyriacotheriidae are a family of unusual small-bodied pantodonts known from the Paleocene of the Western Interior of North America. Cyriacotheriids possess a suite of dental characters similar to that of pantodonts (e.g., molar dilambdodonty, lingual molar hypoconulids), as well as several divergent features (e.g., molarized premolars, strong molar conules) that have been interpreted as “dermopteran-like.” the unusual combination of pantodont and dermopteran-like characters, combined with a limited fossil record, has made attempts at understanding the broader relationships of Cyriacotheriidae difficult. This paper reports on a new genus and two new species of cyriacotheriids from the Paleocene of Alberta, Canada, with both species significantly older than those of the only previously described cyriacotheriid, Cyriacotherium. Collectively, the dentitions of these new taxa exhibit derived characters seen in Cyriacotherium (e.g., robust molar conules, strong molar dilambdodonty) in addition to a number of plesiomorphies seen in more basal pantodonts (e.g., conspicuous molar entoconids, deep premolar ectoflexus) and, importantly, posterior premolars that are weakly molariform and non-dilambdodont. A phylogenetic analysis of the new cyriacotheriid, basal pantodonts, dermopterans, and dermopteran-like eutherians resulted in Cyriacotheriidae nesting within a monophyletic Pantodonta. the results strengthen previous hypotheses regarding the pantodont affinities of the family, and suggest that the dermopteran-like features seen in the more derived Cyriacotherium were acquired convergently. Although the discovery of new cyriacotheriids sheds light on the evolutionary history of the family, it cannot resolve the ongoing questions of pantodont origins; nonetheless, their discovery in strata of early Paleocene age indicates that significant parts of the evolutionary history of Cyriacotheriidae, and North American pantodonts more generally, have yet to be discovered.


1997 ◽  
Vol 71 (3) ◽  
pp. 479-484 ◽  
Author(s):  
M. S. Fernández

A large ichthyosaur from the Early Tithonian (Late Jurassic) of the Neuquén province, Argentina, represents a new genus and species, Caypullisaurus bonapartei, within the family Ichthyosauridae. The holotype is the most complete skeleton of a mature ichthyosaur known to date from the Jurassic of South America. In comparison with other Late Jurassic ichthyosaurs, the new taxon shares a long and slender rostrum, degenerate dentition in adults, and the enlargement of the orbit with Ophthalmosaurus. Unlike Ophthalmosaurus, the forefin of Caypullisaurus has four major digits composed of tightly packed, polygonal phalanges, and pre- and post-axial accessory digits. Caypullisaurus demonstrates that ichthyosaurs were more diverse during the Late Jurassic than thought previously.


1999 ◽  
Vol 73 (4) ◽  
pp. 677-681 ◽  
Author(s):  
Marta S. Fernández

A large ichthyosaur from the Los Molles Formation (Early Bajocian) of the Neuquén Basin, Northwestern Patagonia, Argentina, represents a new genus and species,Mollesaurus periallus.The holotype ofM. periallusnew species represents, along with the type ofChacaicosaurus cayithat was found at the same locality, the only diagnostic ichthyosaur specimens from the Aalenian-Bathonian interval.


Zootaxa ◽  
2021 ◽  
Vol 4933 (1) ◽  
pp. 63-97
Author(s):  
M. CARMEN COBO ◽  
KEVIN M. KOCOT

So far, of the 292 known species of solenogasters (Mollusca, Aplacophora), 62 belong to the clade Pholidoskepia Salvini-Plawen, 1978. Of these, only two have an abyssal distribution (3500–6000 m depth). Among Pholidoskepia, Dondersiidae Simroth, 1893 is the most diverse family. This study contributes to the knowledge of this family with the description of one new genus and six new species from the abyssal South Atlantic Ocean: Dondersia ? foraminosa sp. n., Nematomenia divae sp. n., Nematomenia brasiliensis sp. n., Nematomenia ? guineana sp. n., Helluoherpia vieiralaneroi sp. n. and Inopinatamenia (gen. n.) calamitosa sp. n. Specimens were collected during DIVA (Latitudinal Gradients of Deep-Sea BioDIVersity in the Atlantic Ocean) expeditions in the Guinea (DIVA 2 Me 63/2, 2005) and Brazil (DIVA 3 Me 79/1, 2008) Basins. Specimens were characterized based primarily on the sclerites and internal anatomy, which was studied using histology. The importance of the radula and mantle sclerites for taxonomy is emphasized. Amended diagnoses for the family and some genera within this family are provided. This contribution increases the described diversity of Dondersiidae to ten genera and 38 species and highlights the need for more study of solenogasters in the deep sea. 


2004 ◽  
Vol 78 (6) ◽  
pp. 1187-1191 ◽  
Author(s):  
Erle G. Kauffman ◽  
Héctor A. Leanza

The lower Cretaceous strata of the Neuquén Basin of Argentina are richly fossiliferous and characterized by diverse, primarily normal marine, molluscan-dominated faunas containing many interesting taxa. Among these, in the Lower Hauterivian part of the Agrio Formation at Cerro Mesa (Fig. 1), are diverse, coarsely ornate trigoniid bivalves of the genus Steinmanella Crickmay, 1930, and a new genus and species of ornate Mytilidae (Nodomytilus trigonimimus). The new taxon appears to be convergent in its surface sculpture on the Austral Gondwanian trigoniid Steinmanella transitoria (Steinmann, 1881). This may represent a rare case of convergence, or even mimicry, in the fossil record. The trigoniids have relatively low predation levels among bivalves (Kauffman, personal observation on fossil and recent populations). Convergence on the trigoniid morphotype could have been an adaptive advantage to frequently predated Mytilidae. The new taxon is described herein and compared to co-occurring Steinmanella.


Zootaxa ◽  
2003 ◽  
Vol 282 (1) ◽  
pp. 1 ◽  
Author(s):  
JÜRGEN GUERRERO-KOMMRITZ

A new genus, Portaratrum n. gen. and two new species, one from the Atlantic Ocean and one from the Pacific Ocean are described. The new genus is characterized by a downwardly directed pleonal spur, cheliped basis fused to the cephalothorax, biramous uropods, pars molaris blunt with several terminal spinules. At present the genus is assigned to the family Colletteidae. Both species were collected from depths exceeding 4000 m.


Zootaxa ◽  
2021 ◽  
Vol 4903 (4) ◽  
pp. 542-562
Author(s):  
TANIA NARA BEZERRA ◽  
ELLEN PAPE ◽  
FREIJA HAUQUIER ◽  
ANN VANREUSEL

Erebusssau nom. nov. was originally described by Bussau, (1993) in his PhD thesis “Taxonomische und ökologische Untersuchungen an Nematoden des Peru-Beckens” but the name assigned was already in use, becoming an invalid name. Based on male specimens recovered from the Clarion-Clipperton Fracture Zone, we propose a new replacement nomen for the genus and describe a new species, also adding information about juveniles. Erebussau nom. nov. differs from all other Meyliidae genera by its peculiar offset head. Erebussau profundus sp. nov. differs from Erebussau tenebricosus nom. nov., comb. nov. by its larger size, the presence of pre- and post-cloacal supplements and the shape of the spicules. We also describe a new genus of the family Desmoscolecidae, Odetenema gesarae gen. nov., sp. nov. with an updated key to the genera of the subfamily Tricominae. Odetenema gen. nov. differs from the described Desmoscolecidae genera mainly in terms of the cuticle annulation pattern and the unique end ring with two tubular outlets. Erebussau tenebricosus, E. profundus sp. nov. and Odetenema gesarae gen. nov., sp. nov. have so far only been reported from deep-sea areas where polymetallic nodules are present. 


Zootaxa ◽  
2010 ◽  
Vol 2533 (1) ◽  
pp. 36 ◽  
Author(s):  
SALİH DOĞAN ◽  
GÜLDEM DÖNEL

A new genus, Cryptofavognathus is proposed for two species, Cryptofavognathus afyonensis (Koç & Akyol, 2004) comb. nov. and C. anatolicus sp. nov. The adult female and male of C. anatolicus sp. nov. collected from moss and a bird’s nest are herein described and figured.


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