A new species of Scirrotherium Edmund & Theodor, 1997 (Xenarthra, Cingulata, Pampatheriidae) from the late Miocene of South America

Abstract

Góis, F., Scillato-Yané, G.J., Carlini, A.A. & Guilherme, E. 2013. A new species of Scirrotherium Edmund & Theodor, 1997 (Xenarthra, Cingulata, Pampatheriidae) from the late Miocene of South America. Alcheringa 37, 175–186. ISSN 0311-5518.

A new species of Scirrotherium Edmund & Theodor (Pampatheriidae) is described: S. carinatum. This genus was previously represented by a single species, S. hondaensis Edmund & Theodor, 1997, recorded from the middle Miocene (Laventan) of Colombia. Pampathere remains are common in the ‘Conglomerado osífero’ (late Miocene) of the Ituzaingó Formation in the Paraná River cliffs of Entre Ríos, Chubut (Argentina) and Acre (Brazil). All of them were referred to Kraglievichia paranense, and they are mostly osteoderms. However, only a few of these specimens are strictly consistent with that species. The new species described herein differs from S. hondaensis in having very thin osteoderms with more elaborate ornamentation. The movable band (or imbricate) osteoderms have a sculptured exposed surface and a single transverse row of anterior foramina; the lateral margins are wider and also bear foramina, and the longitudinal central elevation is long and proximally wide, and forms a posteriorly raised crest. This elevation is delimited by a fairly broad and shallow depression on each side, separating the marginal elevation from the longitudinal central one. The exposed surfaces of fixed (or fused) osteoderms bear large and deep anterior foramina, the longitudinal central elevation and delimiting depressions are very pronounced. This new species increases the known diversity of the pampatheres from the ‘Conglomerado osífero’. Additionally, a new nomenclatural scheme for Pampatheriidae osteoderms is proposed.

Flávio Góis [goisf@fcnym]unlp.edu.ar], Gustavo Juan Scillato-Yané [[email protected]], Alfredo Armando Carlini [[email protected]], Departamento Científico Paleontología Vertebrados, Museo de La Plata, Paseo del Bosque, s/n, 1900, La Plata, Buenos Aires, Argentina and CONICET; Edson Guilherme [[email protected]], Universidade Federal do Acre, Laboratório de Pesquisas Paleontológicas (LPP), BR 364, Km 04, 69.915-900. Rio Branco, AC, Brazil. Received 11.5.2012; revised 31.7.2012; accepted 4.9.2012 .

本文描述了Scirrotherium Edmund & Theodor (Pampatheriidae)的一个新种: S. carinatum。该属在此之前仅由一个种所代表: S. hondaensis Edmund & Theodor, 1997, 记录于哥伦比亚的中新世中部 (Laventan)。在Entre Ríos的Paraná河悬崖、Chubut (阿根廷) 和Acre(巴西)的Ituzaingó组的“Conglomeradoosífero”(中新世晚期) 中pampathere的残留体比较常见, 大多数是骨皮。然而, 仅一些标本与那个种严格一致。所描述的新种与S. hondaensis的区别在于: 它的骨皮很薄, 并有更精致的装饰; 覆瓦状骨皮具有刻蚀的出露面及一横排前椎间孔; 侧缘较宽并具椎间孔; 纵向中部高台长且近中心处宽, 形成一后部抬高的脊突。这个高台的两侧以较宽且浅的凹陷为界, 将边缘高台和纵向中部高台分开。固定骨皮的出露面具有大而深的前椎间孔, 纵向中部高台和两侧凹陷非常显著。该新种增大了Conglomeradoosífero中的pampathere 的已知分异度。另外, 我们还提出了Pampatheriidae骨皮的新命名规则。

Key words:

• Scirrotherium sp. nov.
• Ituzaingó Formation
• Entre Ríos
• Puerto Madryn Formation
• Chubut
• Solimões Formation
• Acre

Acknowledgements

The authors wish to thank A.A. Kramarz and J.C. Fernicola from MACN, and M.A. Reguero from MLP for facilitating access to collections under their care. We also want to thank L.R. González Ruiz, for the photographs of the holotype of S. hondaensis deposited in UCMP, and for fruitful comments about Peltephilidae; D. Brandoni, for his helpful comments; E.C. Holanda, C.C. Morgan and N. Nuñez Otaño, for their help with the interpretation of statistical results, and M. Sosa, for the illustrations. Finally, S. McLoughlin (Editor in Chief) and C. Mosto are thanked for help with the English version and M. Ubilla and an anonymous reviewer for suggestions that improved the quality of this paper.