THE AGE AND PROVENANCE OF “ESCHRICHTIUS” CEPHALUS COPE (MAMMALIA: CETACEA)
THE AGE AND PROVENANCE OF “ESCHRICHTIUS” CEPHALUS COPE (MAMMALIA: CETACEA)
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“ESCRICHTIUS”CEPHALUS COPE 的年龄和来源（哺乳动物：鲸类）
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
L. Edwards
中科院分区：
文献类型：
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作者：
R. Weems;L. Edwards
1867 年，爱德华·D·科普 (Edward D. Cope) 描述了鲸鱼化石“Eschrichtius” cephalus。他详细列出了原始材料，包括“两块前上颌骨的相当一部分”、下颌支、寰椎、第三、第四、第五和第七颈椎、尾椎、肱骨、桡骨（最初在科普中被确定为尺骨）。 1867a），两个腕骨和一个指骨（Cope，1867b）。后来，Cope (1890) 推测出许多据称来自同一标本的个体元素，包括先前未描述过的听泡，并提供了该物种的很大程度上推测性的骨骼修复，通过阴影表明骨骼的哪些元素实际上是从类型材料中已知的。这些阴影元素包括一个额外的指骨（不属于目前费城自然科学院的模型材料）和早期描述中未列举的头骨的一些部分（犁骨的一部分和右侧鳞状骨的一部分）。奇怪的是，阴影元素不包括前面在类型材料中列出的寰椎或尾椎。阴影部分是第四到第七个颈椎，而不是最初报道的第三、第四、第五和第七个颈椎，这表明 Cope 在 1890 年改变了他关于第三个颈椎存在而第六个颈椎不存在的想法。在首次描述该物种 20 多年后，Cope 将“E.”cephalus 转移到鲸齿兽属（Cope，1890、1896）。 Hay (1902, 1930) 和 Case (1904) 随后遵循了这一通用分配。该类型材料于 1914 年 8 月 13 日（即科普去世 17 年后）获得费城自然科学院目录编号 ANSP 12691 和 ANSP 12692。它可能是多年前提交给学院的，但没有关于这笔交易的准确信息。第二天，8 月 14 日，在没有任何解释的情况下，额外的颈椎被添加到型号材料中，并给出目录号 ANSP 12693。此后大约六周，即 1914 年 9 月 24 日，另外九块椎骨（未标记为类型）被添加到学院的“E.”cephalus 收藏中，目录号为 ANSP 12941。该材料沉寂了数十年，直到 Kellogg（1968a），在卡尔弗特组须鲸的概要中，在其最初的命名组合 Eschrichtius cephalus Cope 下再次对其进行了讨论。凯洛格表示，几乎可以肯定该物种不属于 Eschrichtius 属；相反，它属于鲸鱼目或与鲸鱼非常接近的已灭绝属。尽管有这样的声明，家乐氏并没有选择改变该物种的通用分配。 Kellogg (1968a) 认为以下材料构成模式标本：ANSP 12691，右下颌骨和左下颌骨后端在冠突水平后被破坏，两个不完整的前上颌骨，一部分上颌骨，一部分犁骨槽，部分鳞骨，左肱骨，左桡骨，两个腕骨和一个指骨； ANSP 12692，第四至第七颈椎（Spamer 等人，1995：267 将其列为第三至第六颈椎）； ANSP 12941，半块寰椎、三块腰椎和两块尾椎（Spamer 等人，1995：267 指出，该批次最初包括九块椎骨）。尽管费城自然科学院于 1914 年将一根轴椎骨 (ANSP 12693) 编入 E. cephalus Cope 类型的一部分，但 Kellogg (1968a) 认识到该标本是 Eschrichtius leptocentrus Cope 的类型 (1867b:147)；它现在被列为失踪（Spamer et al., 1995:267）。 Kellogg (1968a) 绘制的左肱骨是 ANSP 12691 批号的一部分，现在也被列为缺失（Spamer 等人，1995）。 Kellogg (1968a) 指出，由 Cope (1890) 绘制并指定为“E.” cephalus 的鼓泡是存放在美国自然历史博物馆 (AMNH 9846) 的标本，但他没有给出做出这一主张的理由。 AMNH 9846 的目录卡表明该标本来自 Cope 收藏（AMNH 于 1895 年获得），并引用了 Cope (1890) 中的人物，说明了所谓的“E.”cephalus 的大泡（Christopher A. Norris，美国自然历史博物馆，个人通讯，2006 年 5 月）。显然这张目录卡是家乐氏信息的来源。由于自然科学院的“E.”cephalus原始材料不包括鼓泡（Spamer等，1995：266），因此没有理由怀疑该图形标本是AMNH 9846。凯洛格认为该鼓泡太小，不属于“E.”cephalus的模式标本，因此将其排除在该分类单元之外。他的这一观点基于以下事实：一种较小的鲸鱼 Diorocetus hiatus，其鼓泡与 AMNH 9846 一样宽和长。然而，在随后对 Diorocetus hiatus 的描述中，Kellogg (1968b:142) 指出，Pelocetus calvertensis 的头骨比 Diorocetus hiatus 的头骨大得多，但它的头骨要小得多。鼓膜大疱。因此，在鼓室动物中，鼓泡长度和头骨长度之间不存在简单的异速生长关系。因此，科普将该标本归为“Eschrichtius”cephalus 的说法不能被草率地驳回。然而，事实上，这个水泡既没有在最初的描述中被提及，也没有被费城自然科学院的原始材料所收录，这使得它与“E.”cephalus 的联系值得怀疑。尽管 ANSP 目录将批次 12691、批次 12692 和（错误的）标本 12693 列为头颈巨蜥的模式材料，但目录并未说明批次 12941 中的九块椎骨是该模式的一部分（Spamer 等，1995：267）。除了编目为 ANSP 12692 的四个后颈椎外，Cope (1867b) de 通讯作者。 《古脊椎动物学杂志》27(3):752–756，2007 年 9 月 © 2007 年古脊椎动物学会
A fossil balaenopterid whale, ‘Eschrichtius’ cephalus, was described by Edward D. Cope in 1867. He itemized the original material as consisting of “a considerable portion of both premaxillary bones,” the mandibular rami, the atlas, third, fourth, fifth, and seventh cervical vertebrae, a caudal vertebra, humerus, radius (initially identified as an ulna in Cope, 1867a), two carpals, and one phalanx (Cope, 1867b). Later, Cope (1890) figured a number of individual elements purportedly from this same specimen, including an auditory bulla not previously described, and offered a largely speculative skeletal restoration of the species that indicated by shading which elements of the skeleton were actually known from the type material. These shaded elements included an additional phalanx (not among the type material at the Academy of Natural Sciences of Philadelphia at the present time) and some portions of the skull not enumerated in the earlier description (part of the vomer and part of the right squamosal). Curiously, the shaded elements do not include the atlas vertebra or caudal vertebra listed earlier among the type material. The shaded cervicals are the fourth through seventh, rather than the third, fourth, fifth, and seventh as initially reported, which indicates that Cope had changed his mind by 1890 about the third cervical being present and the sixth cervical being absent. More than 20 years after his initial description of this species, Cope transferred ‘E.’ cephalus to the genus Cetotherium (Cope, 1890, 1896). This generic assignment subsequently was followed by Hay (1902, 1930) and Case (1904). The type material received Academy of Natural Sciences of Philadelphia catalog numbers ANSP 12691 and ANSP 12692 on 13 August 1914, 17 years after Cope’s death. It was probably submitted to the Academy many years earlier, but no precise information about this transaction is known. The next day, 14 August, an additional cervical vertebra was added to the type material without explanation and given catalogue number ANSP 12693. About six weeks thereafter, on 24 September 1914, nine more vertebrae (not labeled as type) were added to the Academy’s collection of ‘E.’ cephalus under catalogue number ANSP 12941. The material languished for many decades until Kellogg (1968a), in a synopsis of Calvert Formation baleen whales, discussed it again under its original nomenclatural combination of Eschrichtius cephalus Cope. Kellogg stated that the species almost certainly did not pertain to the genus Eschrichtius; instead, it belonged to Balaenoptera or an extinct genus very close to Balaenoptera. Despite this statement, Kellogg did not choose to change the generic assignment of the species. Kellogg (1968a) considered the following material to constitute the type specimen: ANSP 12691, right and left mandibles with posterior ends destroyed behind level of coronoid processes, both incomplete premaxillary bones, a portion of the maxillary, a portion of the vomerine trough, portions of both squamosals, left humerus, left radius, two carpals, and one phalanx; ANSP 12692, the fourth through seventh cervical vertebrae (Spamer et al., 1995:267 list these as the third through the sixth cervicals); and ANSP 12941, one half of an atlas vertebra, three lumbar vertebrae, and two caudal vertebrae (Spamer et al., 1995:267 state that this lot originally included nine vertebrae). Although the Academy of Natural Sciences of Philadelphia in 1914 catalogued an axis vertebra (ANSP 12693) as part of the type of E. cephalus Cope, Kellogg (1968a) recognized that this specimen instead was the type of Eschrichtius leptocentrus Cope (1867b:147); it is now listed as missing (Spamer et al., 1995:267). The left humerus figured by Kellogg (1968a), which was part of lot ANSP 12691, also now is listed as missing (Spamer et al., 1995). Kellogg (1968a) stated that the tympanic bulla figured by Cope (1890) and assigned by him to ‘E.’ cephalus is a specimen reposited in the American Museum of Natural History (AMNH 9846), but he gave no reason for making this assertion. The catalogue card for AMNH 9846 states that the specimen came from the Cope collection (acquired by AMNH in 1895) and cites the figure in Cope (1890) illustrating the alleged bulla of ‘E.’ cephalus (Christopher A. Norris, American Museum of Natural History, pers. comm., May, 2006). Apparently this catalogue card was the source of Kellogg’s information. Since the original material of ‘E.’ cephalus at the Academy of Natural Sciences does not include a tympanic bulla (Spamer et al., 1995:266), there is no reason to doubt that the figured specimen is AMNH 9846. Kellogg considered this bulla to be too small to belong to the type specimen of ‘E.’ cephalus and thus excluded it from that taxon. He based this opinion on the fact that a much smaller cetothere, Diorocetus hiatus, had tympanic bullae as wide and as long as AMNH 9846. In his subsequent description of Diorocetus hiatus, however, Kellogg (1968b:142) noted that the skull of Pelocetus calvertensis, a cetothere with a skull considerably larger than that of Diorocetus hiatus, has much smaller tympanic bullae. Thus there is no simple allometric relationship between the tympanic bulla length and skull length in cetotheres. For this reason, Cope’s referral of this specimen to ‘Eschrichtius’ cephalus cannot be dismissed summarily. Nevertheless, the fact that this bulla was neither mentioned in the original descriptions nor accessioned with the original material at the Academy of Natural Sciences of Philadelphia makes its association with ‘E.’ cephalus dubious. Although the ANSP catalogue lists lot 12691, lot 12692, and (incorrectly) specimen 12693 as the type material for E. cephalus, the catalogue does not state that the nine vertebrae in lot 12941 are part of the type (Spamer et al., 1995:267). Besides the four posterior cervicals catalogued as ANSP 12692, Cope (1867b) deCorresponding author. Journal of Vertebrate Paleontology 27(3):752–756, September 2007 © 2007 by the Society of Vertebrate Paleontology