Early Miocene hippopotamids (Cetartiodactyla) constrain the phylogenetic and spatiotemporal settings of hippopotamid origin
Early Miocene hippopotamids (Cetartiodactyla) constrain the phylogenetic and spatiotemporal settings of hippopotamid origin
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早期中新世河马（Cetartiodactyla）限制了河马起源的系统发育和时空环境
DOI：
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发表时间：
2010
影响因子：
11.1
通讯作者：
F. Lihoreau
中科院分区：
文献类型：
--
作者：
M. Orliac;J. Boisserie;L. MacLatchy;F. Lihoreau
河马科的亲缘关系是鲸偶蹄目（偶蹄目哺乳动物：鲸类、反刍动物、骆驼、猪类和河马）生殖发育的核心。分子遗传学支持鲸类是河马科的姐妹群，这意味着最早的鲸类（153 Ma）和最早的河马科（160 Ma）之间有一个很长的幽灵谱系。形态学研究提出了两个不同的姊妹分类群：鳄类（特别是古轮兽）或炭疽兽。评估这些系统发育假说需要证实河马科鲜为人知的早期历史。在这里，我们进行了原始的形态系统发育分析，包括几个“suiform”的家庭和以前未经审查的早中新世类群，以测试以前相互矛盾的假设。根据我们的研究结果，Morotochoerus ugandensis和Kulutherium rusingensis，直到现在被认为是唯一的非洲palaeochoerid和唯一的非洲bunodont anthracotheriid，分别明确包括在河马科。它们是已知的最早的拟步甲科，其化石记录可追溯到中新世早期（距今21 Ma）。分析表明，科动物显示出一个未知的分类和身体大小的多样性，并保持限制在非洲的大部分历史，直到最近的中新世。我们的研究结果也证实了深嵌套的河马内的并系anthracotheriidae;这一发现使我们能够重建序列的牙齿创新，先进的硒齿anthracotheriids的sputopotamids，以前的一个来源的主要分歧sputopotamid的起源。分析表明始新世choeropotamids和anthracotheriids之间的密切关系，这种关系可能填补了分子分析所暗示的最早的choeropotamids和鲸目动物之间的进化差距。
The affinities of the Hippopotamidae are at the core of the phylogeny of Cetartiodactyla (even-toed mammals: cetaceans, ruminants, camels, suoids, and hippos). Molecular phylogenies support Cetacea as sister group of the Hippopotamidae, implying a long ghost lineage between the earliest cetaceans (∼53 Ma) and the earliest hippopotamids (∼16 Ma). Morphological studies have proposed two different sister taxa for hippopotamids: suoids (notably palaeochoerids) or anthracotheriids. Evaluating these phylogenetic hypotheses requires substantiating the poorly known early history of the Hippopotamidae. Here, we undertake an original morphological phylogenetic analysis including several “suiform” families and previously unexamined early Miocene taxa to test previous conflicting hypotheses. According to our results, Morotochoerus ugandensis and Kulutherium rusingensis, until now regarded as the sole African palaeochoerid and the sole African bunodont anthracotheriid, respectively, are unambiguously included within the Hippopotamidae. They are the earliest known hippopotamids and set the family fossil record back to the early Miocene (∼21 Ma). The analysis reveals that hippopotamids displayed an unsuspected taxonomic and body size diversity and remained restricted to Africa during most of their history, until the latest Miocene. Our results also confirm the deep nesting of Hippopotamidae within the paraphyletic Anthracotheriidae; this finding allows us to reconstruct the sequence of dental innovations that links advanced selenodont anthracotheriids to hippopotamids, previously a source of major disagreements on hippopotamid origins. The analysis demonstrates a close relationship between Eocene choeropotamids and anthracotheriids, a relationship that potentially fills the evolutionary gap between earliest hippopotamids and cetaceans implied by molecular analyses.
影响因子：
7
作者：
Murphy, William J.;Pringle, Thomas H.;Miller, Webb
通讯作者：
Miller, Webb