Monday, April 27, 2020

[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 dimartinoigen. 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

 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

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