Panochthus subintermedius was originally named by Castellanos in 1933, without any diagnosis and no type material designated. In 1936, he briefly described and designated a holotype for this species and subsequently, in 1942, completed the description, but a diagnosis was still lacking. Some authors have considered this species as nomem nudum, but others have accepted its validity since 1942. In this contribution we propose that Castellanos's 1936 paper is the valid nameestablishing publication for this species. The holotype includes a large portion of dorsal carapace, the caudal tube, and remains of postcranial skeleton, belonging to a single specimen from the Ensenadan Stage/Age (early-middle Pleistocene) of Buenos Aires, Argentina. In contrast to the original description, new observations of the holotype reveal that the superficial surface of the dorsal carapace osteoderms is ornamented with small polygonal figures without a principal one. This ornamentation differs from that of P. intermedius Lydekker (the only species accepted up to now for the Ensenadan), with a central figure in most of its osteoderms. The caudal tube of P. subintermedius differs from those of the Bonaerian-Lujanian species (middle late Pleistocene-early Holocene), in having a sharper distal end, one apical dorsal figure, and a higher number of central figures along the entire dorsal surface. No caudal tube associated with the carapace of P. intermedius is known. Accordingly, P. subintermedius can be clearly distinguished from other Panochthini species by a unique combination of carapace and caudal tube characters. This new combination of characters provides more information on this taxon and other species of Panochthini for future studies in the interrelationships of Glyptodontia. KeywordsGlyptodontia Á Panochthini Á Panochthus Á Ensenadan Á Argentina Á South America Kurzfassung 1933 benannte Castellanos Panochthus subintermedius ohne eine Diagnose zu machen oder Typusmaterial festzulegen. Im Jahr 1936 folgten vom selben Autor eine kurze Beschreibung und die Definition des Holotypus (MACN-Pv 5130). Später, im Jahre 1942, schloss Castellanos die Beschreibung ab ohne eine Diagnose zu stellen. Einige Autoren betrachten diese Art als nomen nudum, während andere ihre Gültigkeit seit 1942 akzeptieren. In diesem Beitrag plädieren wir dafür, die Gültigkeit der Artbezeichnung Castellanos (1936) anzuerkennen. Der Holotypus umfasst einen großen Teil des dorsalen Panzers, der kaudalen Knochenscheide und einige Postcranialelemente von einem einzigen Exemplar aus der Ensenada-Stufe (frühes Mittel-Pleistozän) von Buenos Aires (Argentinien). Im Gegensatz zu der ursprünglichen Beschreibung weisen neue Beobachtungen am Holotypus kleine Polygone ohne Zentralstruktur auf den Osteodermen an der dorsalen Oberfläche des Panzers auf. Diese Ornamentierung unterscheidet sich von P. intermedius (LYDEKKER), die bis heute einzige bekannte Art aus dem Ensenadan, indem diese eine Zentralstruktur in den meisten Osteodermen aufweist. Die kaudalen Knochenscheiden von P. ...
RESUMENPanochthus es uno de los géneros de gliptodóntidos de mayores dimensiones y más ampliamente registrado en el Pleistoceno del sur de América del Sur. Una reciente revisión demostró que alberga seis especies distribuidas cronológicamente de la siguiente manera: P. intermedius y P. subintermedius (Pleistoceno tempranoPleistoceno medio, Ensenadense); P. tuberculatus y P. frenzelianus tienen sus biocrones limitados al Pleistoceno medio-Pleistoceno tardío (Bonaerense-Lujanense), mientras que P. greslebini y P. jaguaribensis solo pueden referirse al Pleistoceno sensu lato. En la presente contribución se da a conocer el registro más antiguo de Panochthus, representado por el material MMP 5171, procedente del Plioceno tardío (Aloformación Playa Los Lobos, Formación Chapadmalal; Chapadmalalense; Biozona de Paraglyptodon chapalmalensis) de la localidad de Mar del Plata, Buenos Aires, Argentina. El material consiste en un gran fragmento de coraza dorsal y en varios trozos de osteodermos asociados, asignables a una especie indeterminada de Panochthus. Uno de los caracteres más significativos es la presencia, a nivel de la superficie expuesta de los osteodermos, de figuritas que siguen un evidente patrón reticular, solo observable en Panochthus. Desde el punto de vista bioestratigráfico, es llamativa la ausencia de registros de Panochthus en la Edad Marplatense (Plioceno tardío-Pleistoceno temprano).Palabras clave: Panochthus; Chapadmalalense; Plioceno; Pleistoceno; Argentina ABSTRACTPanochthus is one of the largest sized and most frequently recorded genera of Pleistocene South American Glyptodontidae. A recent taxonomic revision shows that the genus includes six species: P. intermedius and P. subintermedius (early Pleistocene-middle Pleistocene), P. tuberculatus and P. frenzelianus (middle Pleistocene-late Pleistocene), whereas P. greslebini and P. jaguaribensis only can be referred to the Pleistocene sensu lato. In this contribution the oldest record of the genus Panochthus (MMP 5171) is presented and described. The remains came from the late Pliocene (Playa Los lobos Aloformation, Chapadmalal Formation; Chapadmalalan; Paraglyptodon chapalmalensis Biozone) of the Mar del Plata, Buenos Aires province, Argentina. The material is represented by a considerable fragment of dorsal carapace and some associated osteoderms, which are assignable to an indeterminate species of Panochthus. One of the most significant characters in the exposed surface of the osteoderms is the presence of a clear "reticular" pattern, a character only observed in Panochthus. From a biostratigraphic viewpoint, it is remarkable the absence of records of Panochthus in the Marplatan Age/Stage (late Pliocene-early Pleistocene).
Revision of the genus Nopachtus Ameghino and Phlyctaenopyga Cabrera (Xenarthra, Glyptodontidae, Hoplophorinae) from the late Miocene and Pliocene of Argentina. This work presents the first formal diagnosis for two genera of Hoplophorinae glyptodons, Nopachtus and Phlyctaenopyga, as well as for the species they incluye. In addition, a new species of Nopachtus is recognized for the Montehermosan, and a new combination is proposed: Phlyctaenopyga trouessarti. Precise geographical and stratigraphic provenance is provided for all the analyzed taxa. The most significant differences between Phlyctaenopyga and Nopachtus lie in the osteoderms, especially in the degree of convexity of the central figures and the number of peripheral figures that surround them. Although the central figure is convex in both genera, it is more "bulbous"/ "bubble-shaped" in Phlyctaenopyga compared to Nopachtus. Lastly, in Phlyctaenopyga the peripheral figures are arranged in two or three rows, with 18 to 23 figures in the first row. In the genus Nopachtus there are never more than two rows peripheral figures, and the first one comprises 12 figures.Key words: Hoplophorinae, Nopachtus, Phlyctaenopyga, Mio-Pliocene, Argentina.Resumen: En esta contribución se presentan por primera vez diagnosis formales de dos géneros de gliptodontes Hoplophorinae, Nopachtus y Phlyctaenopyga, así como de las especies que incluyen. Se reconoce además, para el Montehermosense, una nueva especie de Nopachtus y se plantea una nueva combinación: Phlyctaenopyga trouessarti. Asimismo, se precisa la procedencia geográfica y estratigráfica de los taxones aquí analizados. En este sentido, las diferencias más significativas entre Phlyctaenopyga y Nopachtus se encuentran a nivel de los osteodermos, principalmente en el grado de convexidad de la figura central y al observar el número de figuritas periféricas que rodean a ésta. Si bien en ambos géneros la figura central es convexa, en Phlyctaenopyga es más "ampollada" que en Nopachtus. Por último, en el caso de Phlyctaenopyga, las figuritas periféricas están dispuestas en dos o tres hileras, presentando la primera de 18 a 23 figuritas. En el género Nopachtus nunca hay más de dos hileras y la primera, presenta 12 figuritas periféricas.
Panochthus and Glyptodon are the Pleistocene Glyptodontidae having the greatest range of latitudinal distribution and elevation in South America. The most recent revisions of Panochthus recognized its high taxonomic diversification mainly distributed in the Chaco-Pampean region of Argentina, Uruguay, southern Bolivia and southern and north-eastern Brazil, while the Andean records are poorly known. This contribution aims: (a) to describe a new species of Panochthus from the Pleistocene of the surroundings of Potosi (Bolivia), which represents one of the highest known elevation records for fossil Xenarthra; (b) to carry out a phylogenetic analysis in order to test its location in Panochthus and relationship to some allied genera; (c) to discuss some palaeobiogeographical and morphological implications. The results show that, in agreement with previous studies, Panochthus is a natural group, being Propanochthus the sister taxa. This conclusion agrees, at least in part, with the original interpretation of Burmeister, who recognized Pr. bullifer as belonging to Panochthus. The genera Nopachtus and Phlyctaenopyga are more closely related to some 'Plohophorini' than to the clade Propanochthus + Panochthus. Within Panochthus, this new species occupies a relatively basal position as a sister taxon of the clade composed of P. tuberculatus, P. intermedius, and P. greslebini.
-REDESCRIPTION AND DESIGNATION OF A NEOTYPE OF PANOCHTHUS TUBERCULATUS (OWEN) (MAMMALIA, CINGULATA, GLYPTODONTIDAE). We design a neotype for Panochthus tuberculatus (Owen), given that the holotype is missing. A diagnosis and detailed description of the neotype is provided. Glyptodon tuberculatus is the type species of Panochthus Burmeister, one of the genera of giant Pleistocene glyptodonts. P. tuberculatus is recorded in the Bonaerean (late middle Pleistocene) and Lujanian (thus far only for the late Pleistocene lapse of this age) of Argentina, Uruguay, Brazil, Paraguay and, with doubts, Bolivia. Firstly, the species was recognized on the basis of two fragments of dorsal armor; this type material (two syntypes) must be considered as lost, given that it has not been found in the collections of British Museum Natural History, where it was deposited. It is essential that material assigned to P. tuberculatus be made available, to establish the validity of each of the 19 species referred to this genus. The selected material is the complete specimen MLP 16-29, from the Bonaerean of Tapalqué (Buenos Aires Province, Argentina). The specimen of P. tuberculatus MLP 16-29 fulfills all the conditions required by the International Code of Zoological Nomenclature and the designed neotype satisfies all the required subsections. The conclusions are: (i) the specimen MLP 16-29, consisting of nearly complete skeleton and armor of a glyptodontid, until now referred to P. morenoi, becomes the neotype of P. tuberculatus; and (ii) consequently, P. morenoi (sensu Ameghino, 1889), is a synonym of P. tuberculatus.
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