Skull anatomy of the Oligocene toothed mysticete Aetioceus weltoni (Mammalia; Cetacea):: Implications for mysticete evolution and functional anatomy
Skull anatomy of the Oligocene toothed mysticete Aetioceus weltoni (Mammalia; Cetacea):: Implications for mysticete evolution and functional anatomy
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DOI：
10.1111/j.1096-3642.2008.00414.x
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发表时间：
2008-10-01
影响因子：
2.8
通讯作者：
Berta, Annalisa
中科院分区：
文献类型：
--
作者：
Demere, Thomas A.;Berta, Annalisa
产于北太平洋渐新世岩石中的Aetiocetidae科有齿神秘鲸在解释鲸类演化中起着关键作用，因为它们在等级上介于dorudontine古鲸和无齿神秘鲸之间。对产于美国俄勒冈州渐新世晚期（28-24 Ma）的Aetiocetus weltoni正模头骨进行了进一步的研究，揭示了基颅、喙和齿的额外形态特征，这些特征对神秘动物的进化和功能解剖具有重要意义。Aetiocetus weltoni的腭保留了小型的腭侧孔和相关的微妙的沟，这似乎是同源的突出腭孔和沟，出现在沿着腭的外侧部分，在现存的mysticopathy。在现代须鲸中，这些孔允许上级肺泡动脉的分支通过，该动脉为发育中的须鲸架的上皮细胞提供血液。作为同源结构，A. weltoni建议须鲸存在于这个渐新世牙齿mysticete。支序分析的46颅和牙齿的字符支持单系的Aetiocetidae，有齿的mysticulus Janjucetus和Mammalodon定位为连续的姐妹类群。Morawanacetus是最早分化的aetiocetid，Chonecetus是Aetiocetus物种的姐妹分类群。(C)2008年，伦敦林奈学会。
Toothed mysticetes of the family Aetiocetidae from Oligocene rocks of the North Pacific play a key role in interpretations of cetacean evolution because they are transitional in grade between dorudontine archaeocetes and edentulous mysticetes. The holotype skull of Aetiocetus weltoni from the late Oligocene (28-24 Ma) of Oregon, USA, has been further prepared, revealing additional morphological features of the basicranium, rostrum and dentary that have important implications for mysticete evolution and functional anatomy. The palate of Aetiocetus weltoni preserves diminutive lateral palatal foramina and associated delicate sulci which appear to be homologous with the prominent palatal foramina and sulci that occur along the lateral portion of the palate in extant mysticetes. In modern baleen whales these foramina allow passage of branches of the superior alveolar artery, which supplies blood to the epithelia of the developing baleen racks. As homologous structures, the lateral palatal foramina of A. weltoni suggest that baleen was present in this Oligocene toothed mysticete. Cladistic analysis of 46 cranial and dental characters supports monophyly of the Aetiocetidae, with toothed mysticetes Janjucetus and Mammalodon positioned as successive sister taxa. Morawanacetus is the earliest diverging aetiocetid with Chonecetus as sister taxon to Aetiocetus species. (C) 2008 The Linnean Society of London.