Oliveira Paulo V, Ribeiro Ana Maria, Oliveira Edison V, Viana Maria Somália S
Programa de Pos-Graduacao em Geociencias, Universidade Federal de Pernambuco, Recife, PE, Brasil.
Museu de Ciencias Naturais, Fundacao Zoobotanica do Rio Grande do Sul, Porto Alegre, RS, Brasil.
An Acad Bras Cienc. 2014 Mar;86(1):147-58. doi: 10.1590/0001-3765201420120029. Epub 2013 Dec 1.
This paper deals with xenarthrans osteoderms assigned to Dasypus aff. D. novemcinctus, Euphractus sexcinctus and Cabassous sp. The material was collected in subsurface, from 0.10 to 0.60 m in the Urso Fóssil Cave, Parque Nacional de Ubajara, State of Ceará, northeastern Brazil. The ages of sediment samples from levels 4 and 5 (depths of 0.40 and 0.50 m) were determined by thermoluminescence technique, and indicated ages of 8,000 and 8,200 years BP for each layer respectively. The presence in these layers of early Holocene xenarthrans taxa can contribute to the understanding of the biotic evolution of the northwest region of Ceará during the last 10,000 years. Two of the three identified taxa still occur in the region: Dasypus novemcinctus and Euphractus sexcinctus. The Dasypodidae fauna here reported includes animals with generalist feeding habits and current wide geographical distribution. It is suggested, therefore, that the climatic and environmental conditions in the early Holocene were very similar the actual ones, and that the absence of Cabassous may be conditioned to other factors, such as anthropogenic action and loss of habitat by fragmentation of the vegetation.
本文研究了归类于达斯ypus aff. D. novemcinctus、Euphractus sexcinctus和Cabassous sp.的贫齿目动物的骨板。这些材料是在巴西东北部塞阿拉州乌巴雅拉国家公园乌尔索化石洞穴地下0.10至0.60米处采集的。通过热释光技术测定了第4层和第5层（深度分别为0.40米和0.50米）沉积物样本的年龄，结果表明每层的年龄分别为距今8000年和8200年。这些全新世早期贫齿目动物类群在这些层中的存在有助于了解塞阿拉州西北地区过去10000年的生物进化。已识别的三个类群中有两个仍存在于该地区：九带犰狳（Dasypus novemcinctus）和六带犰狳（Euphractus sexcinctus）。这里报道的犰狳科动物群包括具有广泛食性和当前广泛地理分布的动物。因此，有人认为全新世早期的气候和环境条件与现在非常相似，而Cabassous的消失可能受其他因素制约，如人为活动和植被破碎导致的栖息地丧失。
