[PaleoMammalogy • 2024] Parutaetus oliveirai • Revealing the Diversity of Paleogene Cingulates from Brazil: A New Species of Parutaetus (Cingulata: Chlamyphoridae: Euphractinae) in the Guabirotuba Formation (middle–late Eocene)

Parutaetus oliveirai

 Klimeck, Ciancio, Sedor & Kerber, 2024

 DOI: doi.org/10.1080/02724634.2024.2403581  

  Researchgate.net/publication/384656990

 x.com/KerberLeonardo

Art by Márcio L. Castro.

ABSTRACT

Parutaetus is an early-diverging Euphractinae cingulate that inhabited South America during the middle Eocene–early Oligocene. Four species are known: P. chicoensis, P. clusus, P. chilensis, and P. punaensis. Here, we describe a new species of this genus from Guabirotuba Formation (middle-upper Eocene of Brazil). The osteoderms differ from other species of the genus by presenting: (i) more surface glandular and piliferous foramina; (ii) the articulation surface of the area between the osteoderms is flat and full of pronounced, round, and anastomosed projections forming serrated external and medial edges with a median projection (indentations); and (iii) larger size than other species of the genus. In combination, this suite of traits is not present in other species of the genus. The increase in the number of surface glandular and piliferous foramina may be associated with the global cooling that occurred during the middle–late Eocene that affected the South American fauna. Finally, the new species expands the knowledge about the diversity of taxa that inhabited southeast South America during the Paleogene.

External views of the fixed osteoderms of Parutaetus oliveirai.

 Hypothetical artistic reconstruction of Parutaetus oliveirai in the middle-late Eocene of Brazil.

Art by Márcio L. Castro.

 Parutaetus oliveirai

Tabata D. F. Klimeck, Martín R. Ciancio, Fernando A. Sedor and Leonardo Kerber. 2024. Revealing the Diversity of Paleogene Cingulates from Brazil: A New Species of Parutaetus (Euphractinae) in the Guabirotuba Formation (middle–late Eocene). Journal of Vertebrate Paleontology. 44(1);  e2403581. DOI: doi.org/10.1080/02724634.2024.2403581  

  Researchgate.net/publication/384656990_Revealing_the_diversity_of_Paleogene_cingulates_from_Brazil_a_new_species_of_Parutaetus_in_the_Guabirotuba_Formation

 x.com/KerberLeonardo/status/1844710941260173615

[PaleoMammalogy • 2024] Large-sized Mammalian Coprolite containing Ground Sloth Osteoderms from the Upper Pleistocene Touro Passo Formation of Brazil

in Jacob, Diniz, Kerber, Dentzien-Dias et Francischini, 2024.

DOI: 10.1016/j.jsames.2023.104715  

Artwork: Júlia d'Oliveira twitter.com/tupandactylus

Abstract

Coprolites provide information about the presence, diet, and feeding behavior of the producer, besides the trophic relationships between extinct taxa and the regional paleoclimatic context where these organisms lived. Here, we present a paleobiological and paleoecological investigation of a Late Pleistocene carnivore coprolite found in southern Brazil (Touro Passo Formation, Rio Grande do Sul). Our analyses include morphological and morphometric approaches employing scanning electron microscopy, energy-dispersive X-ray spectroscopy, and CT-scanning. The analyzed coprolite is cylindrical, measuring 180 mm in length and 40 mm maximum in diameter, and contains a high proportion of phosphorus and calcium. Interestingly, it presents a large quantity of 102 osteoderms attributed to a Pleistocene ground sloth (Mylodontidae indet.). The size and contents of the coprolite suggest that it was produced by a large carnivorous animal comparable to representatives of Smilodon or another large carnivore mammal. The structure of the osteoderms resembles the morphological pattern found in Mylodontidae, but they are smaller than those described for adult individuals, suggesting that the coprolite producer possibly fed on a juvenile ground sloth. Palynological analysis was also performed, and the low pollen content indicates accidental consumption of plants or pollen, through the viscera of the prey or with the ingestion of water. These paleoenvironmental data suggest that the coprolite producer may have inhabited floodplain regions near river courses, where the coprolite was deposited. These results help to understand the ecological dynamics during the Late Pleistocene of South America.

Coprolite producer

The coprolite MCP-5176-PV was evidently produced by a carnivore, given its cylindrical morphology, whitish-gray color, and phosphatic composition. Moreover, the producer, which ingested (at least) the osteoderm-bearing portion of a giant sloth skin, was of a considerable size, based on its feces large dimensions.

Animals from the Late Pleistocene of South America that were big enough to produce the coprolite MCP-5176-PV include mammals (mainly canids, felids, and ursids) and crocodilians (e.g., ...

Conclusions: 

This study reveals new evidence on the food chain dynamics in the Late Pleistocene of southern Brazil. The coprolite described here was produced by a large carnivorous animal, probably a felid comparable in size to Smilodon populator, Panthera onca, and Puma concolor. This animal fed on a ground sloth, as revealed by the presence of more than 102 osteoderms in the coprolite. These ossicles are regarded as Mylodontidae osteoderms, but smaller than those associated with adult ground sloths, ...

Thândara Jacob, Débora Diniz, Leonardo Kerber, Paula Dentzien-Dias and Heitor Francischini. 2024. A Large-sized Mammalian Coprolite containing Ground Sloth Osteoderms from the Upper Pleistocene Touro Passo Formation of Brazil. Journal of South American Earth Sciences. 133, 104715. DOI: 10.1016/j.jsames.2023.104715

 twitter.com/tupandactylus/status/1731726812797972855

[PaleoMammalogy • 2023] Plohophorus avellaneda • A New Species of Plohophorus Ameghino (Cingulata: Glyptodontidae) from the latest Pliocene–earliest Pleistocene of the Pampean Region (Argentina): the Last Survivor of A Neogene Lineage

Plohophorus avellaneda

 Quiñones, Cuadrelli, Reyes, Luna, Poiré & Zurita, 2023

DOI: 10.1080/14772019.2023.2246963 

 twitter.com/JournalSystPal

 

Abstract

Within xenarthrans, two large groups are recognized, Pilosa (anteaters and sloths) and Cingulata (armoured xenarthrans). The latter contains Glyptodontidae, one of the most bizarre and enigmatic groups of animals that ever lived. Recent phylogenetic proposals show an early Miocene divergence into two clades, one of northern origin (Glyptodontinae) and the other with its oldest records in the early–middle Miocene of southern South America, which groups most of the recognized diversity. Although knowledge of the ‘austral clade’ has increased recently, several taxa need urgent taxonomic and phylogenetic studies to understand their evolutionary history. One case is represented by the ‘Plohophorini’, a tribe that traditionally included several genera (Plohophorus, Pseudoplohophorus, Phlyctaenopyga, Stromaphorus and Stromaphoropsis), from the late Miocene–Pliocene of the Pampean and North-Western regions of Argentina, and Uruguay. A new and terminal species of Plohophorus, Plohophorus avellaneda sp. nov., coming from the El Polvorín Formation (Pampean region of Argentina) is here reported and described, and represents the first case of a Neogene genus of glyptodont crossing the Plio–Pleistocene boundary (c. 2.53 Ma). In addition, the palaeohistological analysis on the osteoderms (the first for ‘Plohophorini’) reveals some characters not observed in other glyptodonts, highlighting its potential phylogenetic importance. The phylogenetic analysis corroborates that the well-characterized species of ‘Plohophorini’ of Uruguay and the Pampean region of Argentina (‘eastern Plohophorini’) constitute a natural group within the austral clade, since both species of Plohophorus (P. avellaneda + P. figuratus) cluster together, and are the sister taxa of Ps. absolutus + Ps. benvenutti. Along the evolutionary history of Plohophorini an increase in body mass is observed, reaching its maximum with P. avellaneda sp. nov. (c. 471 ka). Despite the high frequency of late Pliocene records, Plohophorini disappear completely from the fossil record during the Pleistocene, suggesting that this character was negatively selected.

 

Keywords: glyptodonts, evolutionary history, ‘austral clade’, morphology, palaeohistology

Plohophorus avellaneda sp. nov.

 

Sofía Inés Quiñones, Francisco Cuadrelli, Martin de los Reyes, Carlos Alberto Luna, Daniel Gustavo Poiré and Alfredo Eduardo Zurita. 2023. A New Species of Plohophorus Ameghino (Cingulata, Glyptodontidae) from the latest Pliocene–earliest Pleistocene of the Pampean Region (Argentina): the Last Survivor of A Neogene Lineage. Journal of Systematic Palaeontology. 21(1); 2246963. DOI: 10.1080/14772019.2023.2246963

  twitter.com/JournalSystPal/status/1707723605323243971

[PaleoMammalogy • 2022] Spinal Fracture reveals An Accident Episode in Eremotherium laurillardi (Xenarthra, Megatheriidae) shedding light on the Formation of A Fossil Assemblage

 Eremotherium laurillardi  Lund, 1842

in de S. Barbosa, de Araújo-Júnior, ... et Oliveira, 2022. 

DOI 10.1038/s41598-022-08107-1

Artwork by Júlia d’Oliveira.  twitter.com/tupandactylus

Abstract

The Toca das Onças cave is one of the most important Quaternary mammal deposits of Brazil. Two different hypotheses have been proposed to explain the preservation mode of its skeletal remains: either the animals climbed down into the cave, or it could have functioned as a natural trap. Evaluation of pathological modifications on three articulated vertebrae of a single adult giant ground sloth Eremotherium laurillardi reveals a particular type of bone fracture caused by compressive force on the vertebral column, which split the vertebral bodies in the sagittal plane. This diagnosis suggests that the animal accidentally fell into the cave, in accordance with the second hypothesis proposed to the incorporation mode of skeletal remains into the cave.

Artistic reconstruction of the suggested fall of the individual Eremotherium laurillardi into the cave.

Artwork by Júlia d’Oliveira.

Eremotherium laurillardi Lund 1842

Fernando H. de S. Barbosa, Hermínio I. de Araújo-Júnior, Isadora da Costa, André Vieira de Araújo and Edison Vicente Oliveira. 2022. Spinal Fracture reveals An Accident Episode in Eremotherium laurillardi shedding light on the Formation of A Fossil Assemblage. Scientific Reports. 12: 4119. DOI 10.1038/s41598-022-08107-1

 twitter.com/tupandactylus/status/1501532787056250882

[PaleoMammalogy • 2020] Chlamyphractus dimartinoi • A New Fairy Armadillo (Cingulata, Chlamyphorinae) from the upper Miocene of Argentina: First Fossil Record of the most Enigmatic Xenarthra

Right hemimandibles of fossil and extant chlamyphorines.
 A-C, Chlamyphractus dimartinoi, gen. et sp. nov., MMH-CH-87-7-100.  D-F, Chlamyphorus truncatus, CD-UNNE 1048.  G-I, Calyptophractus retusus, CML 03080. 

Chlamyphractus dimartinoi

Barasoain, Tomassini, Zurita,  Montalvo & Superina, 2020

 DOI: 10.1080/02724634.2019.1716778 

 Reconstruction by P. Cuaranta.

ABSTRACT

Recent molecular analyses suggest that the evolutionary history of Cingulata (Xenarthra) could be more complex than believed previously. An ancient divergence was proposed for armadillos, recognizing two large monophyletic groups: Dasypodidae (including Dasypodinae) and Chlamyphoridae (including Euphractinae, Tolypeutinae, and Chlamyphorinae). Extant Chlamyphorinae (fairy armadillos) are among the most bizarre, elusive, and unknown mammals of the world. Here, we report the first accurate fossil record of this enigmatic xenarthran from the upper Miocene of the Argentine Pampas in southern South America, which represents a new genus and species (Chlamyphractus dimartinoi, gen. et sp. nov.). The phylogenetic analysis reflects the monophyly of the chlamyphorines. It is well supported by several unambiguous synapomorphies and includes the new fossil taxon as a sister group of the two extant species. This new taxon represents the most basal lineage among Chlamyphorinae and increases its diversity. The morphology of the forelimb suggests that it would have been a good digger, although, unlike extant species, it would not have had ‘fully’ subterranean habits.

FIGURE 2. Right hemimandibles of fossil and extant chlamyphorines.
A-C, Chlamyphractus dimartinoi, gen. et sp. nov., MMH-CH-87-7-100: A, labial view showing the angle between the horizontal and the vertical rami; B, lingual view; C, occlusal view.
 D-F, Chlamyphorus truncatus, CD-UNNE 1048: D, labial view showing the angle between the horizontal and the vertical rami; E, lingual view; F, occlusal view.
G-I, Calyptophractus retusus, CML 03080: G, labial view showing the angle between the horizontal and the vertical rami; H, lingual view; I, occlusal view.

SYSTEMATIC PALEONTOLOGY

Magnorder XENARTHRA Cope, 1889

Order CINGULATA Illiger, 1811

Family CHLAMYPHORIDAE Pocock, 1924

Subfamily CHLAMYPHORINAE Bonaparte, 1850

CHLAMYPHRACTUS, gen. nov.

Etymology— Chlamyphractus, from the Ancient Greek, Chlamy (alternative form of Chlamydo, meaning cloak, mantle) and phractus (derived from phraktos, meaning fortified, armored). It is a combination of names, considering the morphological resemblance to both extant genera of fairy armadillos (Chlamyphorus and Calyptophractus).

CHLAMYPHRACTUS DIMARTINOI, sp. nov.

Etymology— dimartinoi, in tribute to the late Vicente Di Martino, who carried out field work in the Arroyo Chasicó locality for many years and collected the specimen studied herein.

FIGURE 6. Rump plates of fossil and extant chlamyphorines.
A-C, Chlamyphractus dimartinoi, gen. et sp. nov., MMH-CH-87-7-100. Note the last band of fixed osteoderms fused to the rump plate. The features of these osteoderms are similar to the other isolated fixed osteoderms. A, posterior view; B, dorsal view; C, small fragments (lower margin?).
D, E, Chlamyphorus truncatus: D, bony surface, UNS-CTS1; E, surface covered by the keratinous coat, CD-UNNE 1048.
F, G, Calyptophractus retusus: F, bony surface, MACN 36874; G, surface covered by the keratinous coat, MACN 4110.

FIGURE 10. Reconstruction of Chlamyphractus dimartinoi, gen. et sp. nov., from the upper Miocene of the Argentine Pampas.

 drawn by P. Cuaranta.

Daniel Barasoain, Rodrigo L. Tomassini, Alfredo E. Zurita,Claudia I. Montalvo and Mariella Superina. 2020. A New Fairy Armadillo (Cingulata, Chlamyphorinae) from the upper Miocene of Argentina: First Fossil Record of the most Enigmatic Xenarthra. Journal of Vertebrate Paleontology. 39(5); e1716778. DOI 10.1080/02724634.2019.1716778

Researchgate.net/publication/340420667_A_new_fairy_armadillo_from_the_upper_Miocene_of_Argentina

9 millones de años: Identifican el primer fósil de “pichiciego” similar a los “topos” y descubierto en la laguna de Chasicó en los ´70

todoprovincial.com/9-millones-de-anos-identifican-el-primer-fosil-de-pichiciego-similares-a-los-topos-descubierto-en-la-laguna-de-chasico-en-los-70

[PaleoMammalogy • 2020] Cranial Anatomy and Paleoneurology of the Extinct Sloth Catonyx tarijensis (Xenarthra, Mylodontidae) From the Late Pleistocene of Oruro, Southwestern Bolivia

Catonyx tarijensis (Gervais & Ameghino, 1880)

in Boscaini, Iurino, Quispe, et al., 2020.

DOI: 10.3389/fevo.2020.00069 

Artwork by Dawid A. Iurino. facebook.com/DawidAdamIurino

Extinct scelidotheriine sloths are among the most peculiar fossil mammals from South America. In recent decades, the external cranial anatomy of Pleistocene scelidotheres such as Scelidotherium, Catonyx, and Valgipes has been the subject of numerous studies, but their endocranial anatomy remains almost completely unknown. Today, computed tomographic (CT) scanning methodologies permit the exploration of previously inaccessible anatomical areas through a completely non-destructive process. For this reason, we undertook an analysis of the external and internal cranial anatomy of Catonyx tarijensis from the late Pleistocene of the Department of Oruro, in southwestern Bolivia. One particularly well-preserved specimen allowed detailed observation of all the main cranial osteological features, including the ear region and an almost complete hyoid apparatus, previously unknown for this taxon. Moreover, CT-scanning and subsequent elaboration of digital models of this specimen allowed observation of the brain cavity and cranial sinuses, and reconstruction of the trajectory of the main cranial nerves for the first time in an extinct scelidotheriine sloth. Additionally, we recovered the first three-dimensional reconstructions of the nasal cavity and the turbinates of an extinct sloth. In contrast to the usual depiction, the combined information from the external and internal anatomy suggests reduced lingual protrusion in Catonyx tarijensis, or at least a consistently more limited protrusion of the tongue in comparison with other mylodontid sloths such as Glossotherium robustum. The new morphological information recovered from this extinct sloth is compared with the available information for both extant and extinct forms, providing insights in the paleobiology of the extinct species. The present study reveals the importance of applying these novel non-destructive techniques to elucidate the evolutionary history of sloths.

Keywords: Xenarthra, scelidotheriine sloth, Catonyx tarijensis, skull, anatomy, endocast, hyoid apparatus

FIGURE 1: Map of the locality in which the remains of Catonyx tarijensis MNHN-Bol V 13364 have been recovered. Circles: cities; Star: fossil locality.

Systematic Paleontology

XENARTHRA (Cope, 1889)

PILOSA (Flower, 1883)

FOLIVORA (Delsuc et al., 2001)

MYLODONTIDAE (Gill, 1872)

SCELIDOTHERIINAE (Ameghino, 1904)

Catonyx (Ameghino, 1891)

Catonyx tarijensis (Gervais and Ameghino, 1880)

Holotype: MNHN.F.TAR1260, skull and mandible from the Pleistocene of Tarija Valley (southern Bolivia).

Distribution: Pleistocene deposits of Bolivia, Argentina and Uruguay (McDonald and Perea, 2002; Corona et al., 2013; MiñoBoilini, 2016). 

FIGURE 7: Hypothetical life reconstruction of Catonyx tarijensis showing its inferred feeding behavior. The reconstruction is based on the skull MNHN-Bol V 13364 from the Pleistocene of Oruro (Bolivian Altiplano).

Artwork by Dawid A. Iurino.

 facebook.com/DawidAdamIurino

Conclusions: 

We report novel data on the external and internal cranial anatomy of the scelidotheriine sloth Catonyx tarijensis, further extending knowledge on the cranial morphology of South American extinct sloths. This discovery, from late Pleistocene deposits of the Department of Oruro (southwestern Bolivia), allowed us to extend the paleobiogeographic range of C. tarijensis to more northern latitudes, as well as to the high altitudes of the Bolivian Altiplano.

The specimen described in the present study, a particularly well-preserved skull with associated mandible and hyoid apparatus, corresponds to a subadult individual of Catonyx tarijensis. Combined information from the external and the internal anatomy, obtained through CT-scanning followed by digital modeling techniques, allowed us to analyze several anatomical regions that were unknown for this taxon.

Among these, the ear region, the nasopharyngeal area and the hyoid elements revealed several phylogenetically and functionally informative features. Digital models permitted observations of the brain cavity, neurovascular grooves and cranial sinuses, and comparisons of these features with other Pleistocene mylodontids.

The information presented in this report confirms previous hypotheses on inferred modes of food intake among extinct scelidotheriine sloths. According to the data now available, C. tarijensis was likely a browsing species, which tore vegetation mainly using its strong lips, rather than the tongue. This habit was probably common among Scelidotheriinae and contrasts with that present in its sister clade, Mylodontinae, whose members were predominantly grazing species with smaller lips and more strongly protruding tongues.

The present study represents a further step in assembling broader morphological comparisons of digital endocranial models among extinct sloths, and emphasizes the importance of applying these new methodologies for understanding the evolution of this mammalian group.

Alberto Boscaini, Dawid A. Iurino, Bernardino Mamani Quispe, Rubén Andrade Flores, Raffaele Sardella, François Pujos and Timothy J. Gaudin. 2020. Cranial Anatomy and Paleoneurology of the Extinct Sloth Catonyx tarijensis (Xenarthra, Mylodontidae) From the Late Pleistocene of Oruro, Southwestern Bolivia. Front. Ecol. Evol.  DOI: 10.3389/fevo.2020.00069  

facebook.com/DawidAdamIurino/posts/3137621356282776

[Mammalogy • 2019] Palaeoproteomics resolves Sloth relationships

In the tree, going clockwise from left: extinct West Indian sloth (Acratocnus), extant three-toed sloth or ai (Bradypus), and extant two-toed sloth or unau (Choloepus).
From left to right on the ground are representative giant ground sloths: Mylodon (South America), Megalonyx (North America), and Megatherium (South America).
According to new molecular studies, Bradypus is most closely related to a group that includes Megalonyx and Megatherium. Choloepus is related to Mylodon, but Acratocnus and its West Indian kin represent a separate branch that is distinct from that of all other sloths. 

Human for scale: 1.8.5 m.

Illustration: Jorge Blanco 

in Presslee, Slater, Pujos, et al., 2019. 
  DOI: 10.1038/s41559-019-0909-z

Abstract

The living tree sloths Choloepus and Bradypus are the only remaining members of Folivora, a major xenarthran radiation that occupied a wide range of habitats in many parts of the western hemisphere during the Cenozoic, including both continents and the West Indies. Ancient DNA evidence has played only a minor role in folivoran systematics, as most sloths lived in places not conducive to genomic preservation. Here we utilize collagen sequence information, both separately and in combination with published mitochondrial DNA evidence, to assess the relationships of tree sloths and their extinct relatives. Results from phylogenetic analysis of these datasets differ substantially from morphology-based concepts: Choloepus groups with Mylodontidae, not Megalonychidae; Bradypus and Megalonyx pair together as megatherioids, while monophyletic Antillean sloths may be sister to all other folivorans. Divergence estimates are consistent with fossil evidence for mid-Cenozoic presence of sloths in the West Indies and an early Miocene radiation in South America.

In the tree, going clockwise from left: extinct West Indian sloth (Acratocnus), extant three-toed sloth or ai (Bradypus), and extant two-toed sloth or unau (Choloepus). From left to right on the ground are representative giant ground sloths: Mylodon (South America), Megalonyx (North America), and Megatherium (South America). According to new molecular studies, Bradypus is most closely related to a group that includes Megalonyx and Megatherium. Choloepus is related to Mylodon, but Acratocnus and its West Indian kin represent a separate branch that is distinct from that of all other sloths. Human for scale: 1.8.5 m (6 ft 1 in). Illustration: Jorge Blanco.

Samantha Presslee, Graham J. Slater, François Pujos, Analía M. Forasiepi, Roman Fischer, Kelly Molloy, Meaghan Mackie, Jesper V. Olsen, Alejandro Kramarz, Matías Taglioretti, Fernando Scaglia, Maximiliano Lezcano, José Luis Lanata, John Southon, Robert Feranec, Jonathan Bloch, Adam Hajduk, Fabiana M. Martin, Rodolfo Salas Gismondi, Marcelo Reguero, Christian de Muizon, Alex Greenwood, Brian T. Chait, Kirsty Penkman, Matthew Collins and Ross D. E. MacPhee. 2019. Palaeoproteomics resolves Sloth relationships. Nature Ecology & Evolution. DOI: 10.1038/s41559-019-0909-z

New research shakes up the sloth family tree phys.org/news/2019-06-sloth-family-tree.html via @physorg_com

 twitter.com/freddelsuc/status/1136656399038107649

[PaleoMammalogy • 2018] Neoglyptatelus uruguayensis • A New Species of Neoglyptatelus (Xenarthra, Cingulata) from the Late Miocene of Uruguay Provides New Insights on the Evolution of the Dorsal Armor in Cingulates

Neoglyptatelus uruguayensis 

Fernicola, Rinderknecht, Jones, Vizcaíno & Porpino, 2018

DOI: 10.5710/AMGH.02.12.2017.3150 
 twitter.com/Ameghiniana

Abstract

The genus Neoglyptatelus Carlini, Vizcaíno and Scillato-Yané has been considered a member of Glyptatelinae, a group encompassing the purportedly basal-most glyptodonts. It is up to now represented by two species from Colombia: Neoglyptatelus originalis Carlini, Vizcaíno and Scillato-Yané, from the middle Miocene (a carapace fragment, isolated osteoderms and postcranial bones), and Neoglyptatelus sincelejanus Villarroel and Clavijo, from the middle or late Miocene (a partial carapace and a caudal armor). More scarce material assigned to this genus was recovered from the late Miocene of Uruguay and Brazil. In this article, we describe a new species, Neoglyptatelus uruguayensis, from the late Miocene Camacho Formation, Uruguay, based on an almost complete carapace and several postcranial bones. We conducted a phylogenetic analysis based on 167 morphological characters (23 new ones and 144 from previous analysis) scored for 19 taxa, encompassing some of the best known glyptodontid genera, one pampathere and four armadillos (including the enigmatic genus Pachyarmatherium Downing and White). In the most parsimonious tree that was obtained, Neoglyptatelus forms a clade with Pachyarmatherium (Pachyarmatheriidae), which is the sister group of the glyptodonts + pampatheres clade; consequently, it is not a glyptodont, as previously believed. This result, together with the known stratigraphic and geographic distribution of Neoglyptatelus and Pachyarmatherium, suggests that this new cingulate clade originated in South America and that Pachyarmatherium reached North America during the Plio—Pleistocene. The carapace of Neoglyptatelus and Pachyarmatherium comprises pelvic and scapular shields overlapping each other without separate intervening transverse mobile bands, an arrangement that differentiates both genera from the remaining cingulates.

Keywords: Carapace, Movement, Pachyarmatheriidae, Glyptatelinae, Phylogeny, Caparazón, Movimiento, Pachyarmatheriidae, Glyptatelinae, Filogenia

Figure 2. Complete specimen of the holotype of Neoglyptatelus uruguayensis (MHNM 1642).
1, dorsal view; 2, lateral view; 3, life reconstruction.

Scale bar= 50 mm.

SYSTEMATIC PALEONTOLOGY 

Order CINGULATA Illiger, 1811

Family PACHYARMATHERIIDAE new rank 

Type genus. Pachyarmatherium Downing and White, 1995.

Genus NEOGLYPTATELUS Carlini, Vizcaíno, and Scillato-Yané, 1997

Type species. Neoglyptatelus originalis Carlini, Vizcaíno, and ScillatoYané, 1997

Neoglyptatelus uruguayensis sp. nov.

Derivation of name. uruguayensis; from Uruguay, to emphasize its geographic provenance.

 Juan C. Fernicola, Andrés Rinderknecht, Washington Jones, Sergio F. Vizcaíno and Kleberson Porpino. 2018. A New Species of Neoglyptatelus (Mammalia, Xenarthra, Cingulata) from the Late Miocene of Uruguay Provides New Insights on the Evolution of the Dorsal Armor in Cingulates [UNA NUEVA ESPECIE DE NEOGLYPTATELUS (MAMMALIA, XENARTHRA, CINGULATA) DEL MIOCENO TARDÍO DE URUGUAY PROPORCIONA NUEVAS PERSPECTIVAS SOBRE LA EVOLUCIÓN DEL CAPARAZÓN DORSAL EN LOS CINGULADOS]. Ameghiniana. 55(3):233-252. DOI: 10.5710/AMGH.02.12.2017.3150

 twitter.com/Ameghiniana/status/1032306918990249984

facebook.com/Ameghiniana/photos/2120901014837479

Resumen: El género Neoglyptatelus Carlini, Vizcaíno and Scillato-Yané ha sido considerado un miembro de los Glyptatelinae, un grupo que supuestamente incluye a los gliptodontes basales. Actualmente, está representado por dos especies halladas en Colombia: Neoglyptatelus originalis Carlini, Vizcaíno and Scillato-Yané, del Mioceno medio (fragmento de caparazón, osteodermos aislados y elementos postcraneanos) y Neoglyptatelus sincelejanus Villarroel y Clavijo del Mioceno medio o tardío (parte de un caparazón y coraza caudal). Osteodermos aislados asignados a este género fueron recuperados en el Mioceno tardío de Uruguay y Brasil. En este trabajo, nosotros describimos una nueva especie, Neoglyptatelus uruguayensis, del Mioceno tardío de la Formación Camacho, Uruguay, a base de una coraza casi completa y distintos elementos postcraneanos. Nuestro estudio filogenético se sustenta en 167 caracteres óseos (23 nuevos y 144 utilizados previamente) relevados en 19 taxones, que incluyen los géneros de gliptodontes mejor conocidos, un pampaterio y cuatro armadillos, incluyendo Pachyarmatherium Downing y White. En el árbol más parsimonioso obtenido Neoglyptatelus forma con Pachyarmatherium un clado (Pachyarmatheriidae) hermano del grupo formado por pampaterios + gliptodontes, por lo cual no es un gliptodonte como se sostenía previamente. Este resultado, junto al conocimiento estratigráfico y geográfico de Neoglyptatelus y Pachyarmatherium, sugiere que los Pachyarmatheriidae se habrían originado en América del Sur y que durante el Plio—Pleistoceno Pachyarmatherium arribó a América del Norte. El caparazón de Neoglyptatelus y Pachyarmatherium contiene un escudo escapular y otro pélvico que solapan directamente entre sí, sin mediar bandas movibles transversas; este arreglo morfológico es único entre los cingulados.

[PaleoMammalogy • 2018] Evolutionary Adaptation to Aquatic Lifestyle in Extinct Sloths Thalassocnus Can Lead to Systemic Alteration of Bone Structure

Thalassocnus carolomartini McDonald & Muizon, 2002

 Amson, Billet & de Muizon, 2018

 DOI: 10.1098/rspb.2018.0270

Illustration: Oliver Demuth   twitter.com/OliverDemuth 

Abstract 

Through phenotypic plasticity, bones can change in structure and morphology, in response to physiological and biomechanical influences over the course of individual life. Changes in bones also occur in evolution as functional adaptations to the environment. In this study, we report on the evolution of bone mass increase (BMI) that occurred in the postcranium and skull of extinct aquatic sloths. Although non-pathological BMI in postcranial skeleton has been known in aquatic mammals, we here document general BMI in the skull for the first time. We present evidence of thickening of the nasal turbinates, nasal septum and cribriform plate, further thickening of the frontals, and infilling of sinus spaces by compact bone in the late and more aquatic species of the extinct sloth Thalassocnus. Systemic bone mass increase occurred among the successively more aquatic species of Thalassocnus, as an evolutionary adaptation to the lineage's changing environment. The newly documented pachyostotic turbinates appear to have conferred little or no functional advantage and are here hypothesized as a correlation with or consequence of the systemic BMI among Thalassocnus species. This could, in turn, be consistent with a genetic accommodation of a physiological adjustment to a change of environment.

Keywords: bone mass increase, evolutionary adaptation, phenotypic plasticity, physiological adjustment, Thalassocnus, turbinates

Conclusion: 

Systemic bone structure alteration, formerly known exclusively as a physiological adjustment, was here evidenced to have been retained as an evolutionary adaptation thanks to the outstandingly detailed (both in terms of geological age and anatomy) and early-stage record of a land-to-sea transition in the extinct sloth Thalassocnus. This new result is consistent with a macroevolutionary process of selection on environmentally induced variation of phenotypic plasticity [Gause, 1942; Sultan, 2017]. In other words, the systemic alteration of the highly plastic bone structure that gradually evolved among the species of Thalassocnus may represent an example of a macroevolutionary transition from a phenotypic accommodation (to an environmental change) to a genetic accommodation. In the context of the so-called extended (evolutionary) synthesis, Pigliucci [2010] points out the difficulty of uncovering such examples, which are required to corroborate the hypothesis that phenotypic plasticity has an important macroevolutionary role.

The precise mechanism causing an adjustment (over the course of an individual's life) of bone structure in response to life in water is not understood. However, one can speculate that the shift of a terrestrial animal to an aquatic environment involves an increase in exercise intensity, which was shown to induce BMI [Lieberman, 1996; Biewener & Bertram, 1994]. There does not seem to be a clear influence of swimming on the bone mass of athletes [Gómez-Bruton, et al., 2013] (but differences in other physical activities probably prevent a direct correlation assessment in humans [Gómez-Bruton, et al., 2016]). However, rats that were swim-trained during growth have a greater overall bone mineral content and bone surface than the sedentary controls [McVeigh, et al., 2010] (but bone mineral density did not differ; and see [Bourrin, et al., 1992] for the opposite effect of endurance swim training on trabecular bone). It is noteworthy, however, that swim-trained animals do not necessarily experience a greater overall exercise intensity, as they were found to voluntarily run less outside the experimental exercise than control and running groups [McVeigh, et al., 2010]. Furthermore, bone structure at locations not directly influenced by locomotion, such as the cranial vault, does not seem to have been investigated in swim-trained animals.

The lack of a similarly detailed fossil record in other ancestrally terrestrial tetrapods adapted to an aquatic lifestyle prevented drawing such a conclusion in their respective cases, but a similar process might have occurred during the evolutionary history of at least some of them. BMI is probably the most widespread lifestyle adaptation among aquatic tetrapods. This suggests that genetic accommodation of a trait subject to physiological adjustment such as bone structure alteration might have played an important role in great evolutionary transitions, of which the secondary adaptations of tetrapods to an aquatic lifestyle is an iconic example.

Eli Amson, Guillaume Billet and Christian de Muizon. 2018. Evolutionary Adaptation to Aquatic Lifestyle in Extinct Sloths Can Lead to Systemic Alteration of Bone Structure.  Proc. R. Soc. B. 285: 20180270. DOI: 10.1098/rspb.2018.0270

  

The paper about the crazy pachyosteosclerosis in the skull of the marine sloth #Thalassocnus was published this morning in @RSocPublishing Proceedings B: doi.org/10.1098/rspb.2018.0270 …, to which I contributed my art. It was a pleasure to work with authors. #PaleoArt #SciArt

 twitter.com/OliverDemuth/status/994134938344620032
 facebook.com/photo.php?fbid=10211011701159876 

[Mammalogy • 2018] Taxonomic Review of the Genus Cyclopes Gray, 1821 (Xenarthra: Pilosa), with the Revalidation and Description of New Species

silky anteater  Cyclopes didactylus

photo: Quinten Questel  commons.wikimedia.org

Miranda, Casali, Perini, et al. 2018.    DOI:  10.1093/zoolinnean/zlx079 

Abstract

The taxonomy of Cyclopes didactylus is marked by a confusing history of new names, with few or no references to types, and new subspecies without any verified geographic correspondence. Here, we review the taxonomy of the genus Cyclopes using an integrative approach that combines morphological, morphometric and molecular data. We, therefore, aim to clarify many issues concerning the taxonomy, distribution and conservation status of the valid taxa and describe new previously unrecognized species for the genus. We examined a total of 287 specimens of Cyclopes, including skins and skulls, housed in 20 natural history collections and 33 samples for molecular analyses. Based on evidence provided by molecular phylogenetics using mitochondrial and nuclear DNA, allied with coalescent species delimitation analyses, diagnostic characters of the skull, colour patterns and structures of pelage, we suggest that the genus Cyclopes comprises at least seven species. Four previous species designations are considered valid here: Cyclopes didactylus (Linnaeus, 1758); Cyclopes ida Thomas, 1900; Cyclopes catellus Thomas, 1928; and Cyclopes dorsalis (Gray, 1865). In addition, three new species are described. The results presented here have large implications for the conservation status and management practices of silky anteaters.

Family Cyclopedidae

Genus Cyclopes Gray, 1821

Cyclopes didactylus (Linnaeus, 1758)

Cyclopes ida Thomas, 1900

Cyclopes dorsalis (Gray, 1865)

Cyclopes catellus Thomas, 1928

Cyclopes thomasi sp. nov.

Etymology: The specific name honours Michael Rogers Oldfield Thomas, in recognition of his extensive contribution to mammalogy, and specifically to the taxonomy of Cyclopes.

Cyclopes rufus sp. nov.

Etymology: The specific name rufus (meaning ‘red’ in Latin) refers to the reddish tone of the dorsal coloration of this species.

Cyclopes xinguensis sp. nov.

Etymology: The specific epithet xinguensis refers to the type locality of this species in Vitória do Xingu, Pará, Brazil. Xingu is an indigenous word meaning good and clean water.

The silky anteater (Cyclopes didactylus) 

photo: Quinten Questel/CC 3.0/Wikimedia Commons 

 commons.wikimedia.org 

Flávia R Miranda, Daniel M Casali, Fernando A Perini, Fabio A Machado and Fabrício R Santos. 2018. Taxonomic Review of the Genus Cyclopes Gray, 1821 (Xenarthra: Pilosa), with the Revalidation and Description of New Species.  Zoological Journal of the Linnean Society. zlx079.  DOI:  10.1093/zoolinnean/zlx079 
ResearchGate.net/publication/321733059_Taxonomic_review_of_the_genus_Cyclopes_Xenarthra_Pilosa_with_the_revalidation_and_description_of_new_species

ResearchGate.net/publication/273239016_Cyclopes_didactylus_Pilosa_Cyclopedidae

Brazilian researchers uncover 6 new species of silky anteater
 eurekalert.org/e/84qs via @EurekAlert

 Cientistas brasileiros descobrem seis novas espécies de tamanduás-anões -   ciencia.estadao.com.br/noticias/geral,cientistas-brasileiros-descobrem-seis-novas-especies-de-tamanduas-anoes,70002115814  @estadao

[PaleoMammalogy • 2017] Xibalbaonyx oviceps • A New Megalonychid Ground Sloth (Folivora, Xenarthra) from the Late Pleistocene of the Yucatán Peninsula, Mexico, and Its Paleobiogeographic Significance

Xibalbaonyx oviceps 

Stinnesbeck, Frey, Olguín, Stinnesbeck, Zell, Mallison, González, Núñez, Morlet, Mata, Sanvicente, Hering & Sandoval, 2017.

 DOI: 10.1007/s12542-017-0349-5 

Abstract

Here we describe a new genus and species of giant ground sloth, Xibalbaonyx oviceps (Megalonychidae, Xenarthra), from the drowned cave system of the northeastern Yucatán Peninsula. The specimen is Late Pleistocene in age and was discovered in the Zapote sinkhole (cenote) near Puerto Morelos in the Mexican state of Quintana Roo. Xibalbaonyx oviceps differs significantly from all hitherto known Megalonychidae including those from the Greater Antilles and South America. The new taxon suggests a local Caribbean radiation of ground sloths during the Late Pleistocene, which is consistent with the dispersal of the group along a Mexican corridor.

Keywords: Ground sloths, Pleistocene, Yucatán Peninsula, Mexico 

Systematic palaeontology

Superorder Xenarthra Cope, 1889

Order Pilosa Flower, 1883

Superfamily Megatherioidea Gray, 1821

Family Megalonychidae Gervais, 1855

Diagnosis of the family. Xibalbaonyx oviceps is identified as a member of Megalonychidae based on the following features: dorsal contour of skull evenly convex in lateral view. The glenoid fossa is mediolaterally widened, its posterior surface smooth and the fossa is well separated from the porus acusticus. The lateral plate of the entotympanic is thin with a medial expansion and weak participation in the floor of the tympanic cavity. The paroccipital process is well developed (Patterson et al. 1992; Gaudin 1995, 2004; McDonald et al. 2013b).

Fig. 4: Xibalbaonyx oviceps (Za2014-01) skull in lateral view (left side). 

Fig. 3: Xibalbaonyx oviceps in situ within the Zapote cenote; Skull and mandible (Za2014-01, -05)

Xibalbaonyx oviceps gen. et sp. nov.

Etymology. For the genus: Xibalbá = Maya for “underground” or “place of fear,” dedicated to the cave divers who dive into the “underworld,” the cenotes, and collect the fossils under risky conditions, but also in honor of the Yucatán Peninsula, which is also called the Maya region; “őνυξ” (onyx) = Greek for “claw” or “finger nail;” for the species: oviceps from ovum = Latin for “egg” and caput = “head,” “egghead,” referring to the regularly domed skull roof of the specimen.

Stratigraphic and geographic distribution. The Cenote Zapote 16 Q 0486971 UTM 2305968, Ruta de los Cenotes Puerto Morelos Quintana Roo, Mexico. Late Pleistocene and/or Early Holocene (9.305 ± 35 14C bp, 10.647–10.305 cal bp).

.....

 Conclusions: 

The well-preserved skull and mandible of a ground sloth discovered in the Zapote cenote Cave near Puerto Morelos on the northeastern Yucatán Peninsula of Mexico is here described as a new genus and species of Megalonychidae. The individual, here named Xibalbaonyx oviceps, has a dental formula of 5/4 including a greatly enlarged caniniform tooth of triangular cross-section. This caniniform is separated by a long diastema from the molariform tooth rows in both the lower and upper jaw. The molariform teeth show oval, rounded rectangular to reniform (McDonald et al. 2013b) occlusal shapes with transverse crests. All teeth except for the upper caniniforms, show striations and apicobasal sulci that may be expressed as shallow grooves or deep sulci. The ascending process of the jugal is longer than the descending and middle process of the jugal. The pterygoids are inflated. The glenoid fossa is transversally widened. The skull is elongated and narrow, with a nasional impression on the nasals. The temporal lines are widely separated and do not form a sagittal crest. The skull is narrow and gracile compared that of other Megalonychidae of similar size, such as Megalonyx or Ahytherium. The Zapote ground sloth was a subadult individual, based on the degree of suture fusion in the skull, faint temporal lines and the condition of the occlusion faces of the molariforms. To present knowledge Xibalbaonyx appears to have been endemic on the Yucatán Peninsula, suggesting a local microevolution on this karst desert during the Late Pleistocene.

Sarah R. Stinnesbeck, Eberhard Frey, Jerónimo Avíles Olguín, Wolfgang Stinnesbeck, Patrick Zell, Heinrich Mallison, Arturo González González, Eugenio Aceves Núñez, Adriana Velázquez Morlet, Alejandro Terrazas Mata, Martha Benavente Sanvicente, Fabio Hering and Carmen Rojas Sandoval. 2017. Xibalbaonyx oviceps, A New Megalonychid Ground Sloth (Folivora, Xenarthra) from the Late Pleistocene of the Yucatán Peninsula, Mexico, and Its Paleobiogeographic Significance. PalZ [Paläontologische Zeitschrift]. 91(2); 245–271.   DOI: 10.1007/s12542-017-0349-5

ResearchGate.net/publication/317185046_Xibalbaonyx_oviceps_a_new_megalonychid_ground_sloth_Folivora_Xenarthra_from_the_Late_Pleistocene_of_the_Yucatan_Peninsula_Mexico_and_its_paleobiogeographic_significance

Ancient species of giant sloth discovered in Mexico  ctv.news/M8rqjqN

Tízezer éve élt óriáslajhár maradványaira bukkantak Mexikóban http://www.origo.hu/tudomany/20170817-archeologia-tizezer-eve-elt-oriaslajhar-maradvanyaira-bukkantak-mexikoban.html

Kurzfassung: Die Unterwasserhöhlen auf der nordöstlichen Halbinsel Yukatan zeigen eine artenreiche Ansammlung von Großsäugern aus dem späten Pleistozän und frühen Holozän. Hier beschreiben wir die neue Gattung und Art eines Riesenfaultiers, Xibalbaonyx oviceps (Megalonychidae, Xenarthra), aus der Zapote Doline (Cenote) in der Nähe von Puerto Morelos im mexikanischen Bundesstaat Quintana Roo. Das Exemplar unterscheidet sich signifikant von allen bisher dokumentierten Megalonychidae einschließlich derjenigen von den Großen Antillen und aus Südamerika. Das neue Taxon deutet auf eine lokale karibische Radiation von Bodenfaultieren währen des Spätpleistozäns hin, die mit der Ausbreitung der Gruppe entlang des mexikanischen Korridors übereinstimmt.

Schlüsselwörter: Bodenfaultiere Pleistozän Yukatan Halbinsel Mexiko