Department of Entomology, Natural History Museum, London, United Kindgom.
PLoS One. 2007 Apr 11;2(4):e360. doi: 10.1371/journal.pone.0000360.
The great diversity of the "Phytophaga" (weevils, longhorn beetles and leaf beetles) has been attributed to their co-radiation with the angiosperms based on matching age estimates for both groups, but phylogenetic information and molecular clock calibrations remain insufficient for this conclusion.
A phylogenetic analysis of the leaf beetles (Chrysomelidae) was conducted based on three partial ribosomal gene markers (mitochondrial rrnL, nuclear small and large subunit rRNA) including over 3000 bp for 167 taxa representing most major chrysomelid lineages and outgroups. Molecular clock calibrations and confidence intervals were based on paleontological data from the oldest (K-T boundary) leaf beetle fossil, ancient feeding traces ascribed to hispoid Cassidinae, and the vicariant split of Nearctic and Palearctic members of the Timarchini.
The origin of the Chrysomelidae was dated to 73-79 Mya (confidence interval 63-86 Mya), and most subfamilies were post-Cretaceous, consistent with the ages of all confirmed body fossils. Two major monocot feeding chrysomelid lineages formed widely separated clades, demonstrating independent colonization of this ancient (early Cretaceous) angiosperm lineage.
Previous calibrations proposing a much older origin of Chrysomelidae were not supported. Therefore, chrysomelid beetles likely radiated long after the origin of their host lineages and their diversification was driven by repeated radiaton on a pre-existing diverse resource, rather than ancient host associations.
基于对两组年龄估计的匹配，“Phytophaga”（象甲科、天牛科和叶甲科）的巨大多样性归因于它们与被子植物的共同辐射，但系统发育信息和分子钟校准对于这一结论仍然不足。
对叶甲科（Chrysomelidae）进行了基于三个部分核糖体基因标记（线粒体 rrnL、核小亚基和大亚基 rRNA）的系统发育分析，包括超过 3000 个碱基对的代表大多数主要叶甲科谱系和外群的 167 个分类单元。分子钟校准和置信区间基于最古老的（K-T 边界）叶甲化石的古生物学数据、归因于 Hispoid Cassidinae 的古代取食痕迹以及 Timarchini 的近北极和古北极成员的分歧。
叶甲科的起源可追溯到 73-79 Mya（置信区间为 63-86 Mya），大多数亚科是白垩纪后形成的，与所有已确认的体化石年龄一致。两个主要的单子叶植物取食叶甲科的进化枝形成了广泛分离的分支，证明了对这种古老（早白垩世）被子植物谱系的独立殖民。
以前提出的叶甲科起源更早的校准结果没有得到支持。因此，叶甲科甲虫的辐射很可能发生在它们的宿主谱系起源之后很久，它们的多样化是由对预先存在的多样化资源的反复辐射驱动的，而不是古老的宿主关联。
