Skull morphology and phylogenetic relationships of a new diminutive balaenid from the Lower Pliocene of Belgium
Skull morphology and phylogenetic relationships of a new diminutive balaenid from the Lower Pliocene of Belgium
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DOI：
10.1111/j.1475-4983.2005.00488.x
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发表时间：
2005-07-01
期刊：
影响因子：
2.6
通讯作者：
Bisconti, M
中科院分区：
文献类型：
--
作者：
Bisconti, M
描述了一种新的小型鲸鱼，并将其与所有化石和活鲸鱼类群进行了比较。该标本代表了一个新的属和种，被命名为短鼻鲸 (Balaenella brachyrhynus)。它是在卡洛（比利时安特卫普西北部）的上新世早期发现的，并增加了有关鲸鱼科多样性和进化的新信息。基于比较形态学和系统发育分析，短吻鲸在形态上更接近鲸属，包括现存的格陵兰弓头鲸（B. mysticetus），以及来自意大利中部和美国东部的两个上新世物种（B. montalionis 和 B. Ricei）。 Balaenella brachyrhynus 的鼻骨非常短，相对于头骨总长度而言，喙部较短，上枕骨水平。对 10 种鲸类和 9 种非鲸类的 81 个形态特征状态进行分支分类处理后发现，一般属于鲸须鲸属的其他小型鲸鱼（包括 Astensis 鲸鱼、鲸须鲸和来自日本的上新世鲸鱼属）更接近现存的 Eubalaena 属（露脊鲸）。由于新的头骨与名义上的鲸鱼属物种非常不同，而且它与鲸鱼属的关系比与真鲸鱼的关系更密切，因此可以得出结论，体型较小是不同鲸鱼科分支的常见状况。
A new small balaenid is described and compared to all fossil and living balaenid taxa. The specimen represents a new genus and species and is named Balaenella brachyrhynus. It was discovered in the Lower Pliocene of Kallo (north-west Antwerp, Belgium) and adds new information on the diversity and evolution of Balaenidae. Based on both comparative morphology and phylogenetic analysis, Balaenella brachyrhynus is morphologically closer to the genus Balaena, including the living Greenland Bowhead whale (B. mysticetus), and two Pliocene species (B. montalionis and B. ricei) from central Italy and the eastern USA. Balaenella brachyrhynus has very short nasals, a short rostrum relative to the total skull length and a horizontal supraoccipital. A cladistic treatment of 81 morphological character states scored for 10 balaenids and nine non-balaenid cetaceans revealed that the other small balaenids generally included in the genus Balaenula (including Balaenula astensis, B. balaenopsis and a Pliocene Balaenula sp. from Japan) are closer to the living genus Eubalaena (the Right whale). As the new skull is so different from the nominal Balaenula species, and as it is more closely related to Balaena than to Eubalaena, it is concluded that a small body size was a common condition in different Balaenidae clades.