Abstract The subterranean rodent Ctenomys is the single living representative of the family Ctenomyidae, and the most diverse genus within Hystricomorpha. Its fossil record begins in the late Pliocene and shows an increase in diversity since the Pleistocene. Here we describe a new middle-sized Ctenomys species from a large cranial sample collected at the archaeological site Quebrada del Real 1 in the high plains of the Pampa de Achala (Cordoba, Argentina). For this goal, we analyzed the cranial and mandibular shape variation through a geometric morphometric approach, and performed a comparative morphological analysis in the context of the living Ctenomys. The new species is characterized by having a wide rostrum with a deep rostral fossa, strong temporal fossa in the frontal, upper incisors strongly procumbent and with grooved enamel, and mandible with low corpus, long procumbent diastema and descending masseteric crest. A phylogenetic analysis demonstrated its close affinity with Ctenomys osvaldoreigi, an extant species from a nearby area. The new species represents the first notice of an extinct Ctenomys species from the Holocene. Given its peculiar morphology, the extinction of this species would have resulted in significant loss of morphological diversity, thus constraining the current boundaries of variation of the genus. The last record of the new species occurs in a period characterized by marked extinction of small mammals in southern South America mainly due to anthropogenic causes.

中文翻译：

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阿根廷中部全新世地下啮齿动物Ctenomys（Rodentia，Ctenomyidae）的一新奇种

摘要 地下啮齿动物 Ctenomys 是 Ctenomyidae 科的唯一活代表，也是 Hystricomorpha 中最多样化的属。它的化石记录始于上新世晚期，并显示自更新世以来多样性有所增加。在这里，我们描述了一种新的中型 Ctenomys 物种，该物种来自在 Pampa de Achala（阿根廷科尔多瓦）高平原的考古遗址 Quebrada del Real 1 收集的大型颅骨样本。为此，我们通过几何形态测量方法分析了颅骨和下颌骨的形状变化，并在活体 Ctenomys 的背景下进行了比较形态学分析。新种的特点是喙宽，喙窝深，额颞窝强，上切牙强烈前倾，釉质有凹槽，下颌骨体低，长卧位间隙和下降的咬肌嵴。系统发育分析表明它与来自附近地区的现存物种 Ctenomys osvaldoreigi 密切相关。这个新物种代表了全新世灭绝的 Ctenomys 物种的第一个通知。鉴于其独特的形态，该种的灭绝将导致形态多样性的显着丧失，从而限制了目前该属变异的边界。新物种的最后记录发生在南美洲南部小型哺乳动物明显灭绝的时期，主要是由于人为原因。来自附近地区的现存物种。这个新物种代表了全新世灭绝的 Ctenomys 物种的第一个通知。鉴于其独特的形态，该种的灭绝将导致形态多样性的显着丧失，从而限制了目前该属变异的边界。新物种的最后记录发生在南美洲南部小型哺乳动物明显灭绝的时期，主要是由于人为原因。来自附近地区的现存物种。这个新物种代表了全新世灭绝的 Ctenomys 物种的第一个通知。鉴于其独特的形态，该种的灭绝将导致形态多样性的显着丧失，从而限制了目前该属变异的边界。新物种的最后记录发生在南美洲南部小型哺乳动物明显灭绝的时期，主要是由于人为原因。