ORIGIN OF THE WHITE SHARK CARCHARODON (LAMNIFORMES: LAMNIDAE) BASED ON RECALIBRATION OF THE UPPER NEOGENE PISCO FORMATION OF PERU
ORIGIN OF THE WHITE SHARK CARCHARODON (LAMNIFORMES: LAMNIDAE) BASED ON RECALIBRATION OF THE UPPER NEOGENE PISCO FORMATION OF PERU
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DOI：
10.1111/j.1475-4983.2012.01201.x
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发表时间：
2012-11-01
期刊：
影响因子：
2.6
通讯作者：
Salas-Gismondi, Rodolfo
中科院分区：
文献类型：
--
作者：
Ehret, Dana J.;Macfadden, Bruce J.;Salas-Gismondi, Rodolfo
白色鲨鱼的分类学起源是一个备受争议的话题。这项研究中提出的新化石证据表明，该属起源于宽齿的“鲭鲨”，Carcharodon（Cosmopolitodus）hastalis，并包括新种C。hubbelli sp. nov. -一个分类单元，展示了C. hastalis和Carcharodon carpelas。来自皮斯科组的标本清楚地表明了现代C. carpellas和化石C.哈斯塔利斯。字符诊断为C。腕骨包括存在齿锯齿和对称的第一上前齿，其在齿排中是最大的，而那些指示C. hastalis包括近中倾斜的第三前（中间）齿。我们还提供了一个重新校准的关键化石层内的皮斯科组，秘鲁使用锆石U-Pb测年和锶比同位素分析。绝对年龄的重新标定表明，胡氏真齿鲨Carcharodon hubbelli sp. nov.的年龄为晚中新世（6-8 Ma）。本研究以新近系皮斯科组的标定为基础，修正和阐明了板鲨的演化。
The taxonomic origin of the white shark, Carcharodon, is a highly debated subject. New fossil evidence presented in this study suggests that the genus is derived from the broad-toothed 'mako', Carcharodon (Cosmopolitodus) hastalis, and includes the new species C. hubbelli sp. nov. - a taxon that demonstrates a transition between C. hastalis and Carcharodon carcharias. Specimens from the Pisco Formation clearly demonstrate an evolutionary mosaic of characters of both recent C. carcharias and fossil C. hastalis. Characters diagnostic to C. carcharias include the presence tooth serrations and a symmetrical first upper anterior tooth that is the largest in the tooth row, while those indicative of C. hastalis include a mesially slanted third anterior (intermediate) tooth. We also provide a recalibration of critical fossil horizons within the Pisco Formation, Peru using zircon U-Pb dating and strontium-ratio isotopic analysis. The recalibration of the absolute dates suggests that Carcharodon hubbelli sp. nov. is Late Miocene (6-8 Ma) in age. This research revises and elucidates lamnid shark evolution based on the calibration of the Neogene Pisco Formation.