Localities with nonmarine Miocene species of <i>Actinocyclus</i> in Japan.

<p>Localities with nonmarine Miocene species of <i>Actinocyclus</i> in Japan.</p

Stratigraphic columnar sections at Iki Island and Noto Peninsula showing stratigraphic position of samples studied.

<p>The position of these sections does not indicate their correlation.</p

SEM photographs of <i>Actinocyclus</i> species from early to middle Miocene lacustrine sediments in Japan.

<p>(<b>A</b>) <i>A</i>. sp. 4. (<b>B, C</b>) <i>A</i>. <i>nipponicus</i>. (<b>D</b>) <i>A</i>. <i>bradburyii</i>. In <b>C</b>, a black arrow indicates a pseudonodulus.</p

Potential effects of eustasy, volcanism, and orogeny on continental planktonic diatoms during the Neogene.

<p>Potential effects of eustasy, volcanism, and orogeny on continental planktonic diatoms during the Neogene.</p

Morphology of <i>Actinocyclus</i> species from early to middle Miocene lacustrine sediments in Japan.

<p>LM photographs show (<b>A</b>) <i>A</i>. sp. 1, (<b>B</b>) <i>A</i>. sp. 2, (<b>C</b>) <i>A</i>. sp. 3, (<b>D</b>) <i>A</i>. sp. 4, (<b>E</b>, <b>F</b>) <i>A</i>. <i>nipponicus</i> (the same specimen at different focal planes) and (<b>G</b>, <b>H</b>) <i>A</i>. <i>bradburyii</i> (the same specimen at different focal planes). SEM photographs show (<b>I</b>) <i>A</i>. sp. 1, (<b>J, K</b>) <i>A</i>. sp. 2 and (<b>L, M, N</b>) <i>A</i>. sp. 3. In <b>M</b>, a black arrow and a black arrowhead indicate a pseudonodulus and a labiate process, respectively.</p

Relative abundances of nonmarine diatom species from Lower to Middle Miocene lacustrine deposits in Japan.

<p>Relative abundances of nonmarine diatom species from Lower to Middle Miocene lacustrine deposits in Japan.</p

Morphological evolution of <em>Stephanodiscus</em> (Bacillariophyta) in Lake Biwa from a 300 ka fossil record

<p>A series of intermittent changes in <em>Stephanodiscus</em> (Bacillariophyta) valve morphology was observed in sediment core materials collected from Lake Biwa, Japan. A constant sedimentation rate reveals a continuous but punctuated pattern of morphological evolution. Morphological parameters, including maximum diameter and fascicle number v. diameter ratio (fascicle density), showed long periods of stasis and less than 10 000-year directional changes. Specifically, directional decreases in fascicle density occurred at 200–190 and 160–150 ka, and increases in maximum diameter occurred at 130–120 ka. According to a morphology-based species definition, a non-branching phylogenetic lineage originating from a cosmopolitan ancestor can be presumed from a morphology-based cladistic analysis and the biostratigraphic record. Evolutionary modes were selected from directional change, random walk, stasis and combined models by a statistical test, paleoTS, to clarify that the sequential changes are composed of relatively long stasis modes and short directional change modes. Global climate change was probably an influence during the early stages of the history of Lake Biwa. </p

Typical assemblages observed in individual sediment samples.

<p>(<b>A</b>) <i>Actinocyclus</i> sp.1 and <i>Aulacoseira</i> spp. from the Yamatoda Diatomaceous Mudstone Member (Yamatoda-5). (<b>B</b>) <i>A</i>. sp. 2 from the Chojabaru Formation (Chojabaru-22). (<b>C</b>) <i>A</i>. sp. 2, <i>Aulacoseira</i> spp. and penates from the Chojabaru Formation (Chojabaru-27). (<b>D</b>) <i>A</i>. sp. 3 and <i>Aulacoseira</i> spp. from the Chojabaru Formation (Chojabaru-5). (<b>E</b>) <i>A</i>. sp. 4 and <i>Aulacoseira</i> spp. from the Ouchi Formation (Ouchi-1). (<b>F</b>) <i>A</i>. <i>bradburyii</i> (upper left), <i>A</i>. <i>nipponicus</i> (center) and <i>Aulacoseira</i> spp. from the RC12-394 core (RC12-394-490).</p

Biochronology with general relative diversities of six lacustrine diatom genera in mid-latitude North America and late Cenozoic global climate changes.

<p>The biochronology is modified from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198003#pone.0198003.ref005" target="_blank">5</a>], which was established by radiometric dating of lacustrine diatomites. Diversity patterns are qualitative and not comparable between genera. The global climate record represented by benthic foraminiferal δ¹⁸O is after [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198003#pone.0198003.ref050" target="_blank">50</a>]. Time scale is from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198003#pone.0198003.ref051" target="_blank">51</a>].</p

Comparison of valve diameter among nonmarine.

<p><b><i>Actinocyclus</i>, <i>Cyclostephanos</i>, <i>Stephanodiscus</i>, <i>Mesodictyon</i> and cyclotelloid species.</b> Data are collected from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198003#pone.0198003.ref013" target="_blank">13</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198003#pone.0198003.ref037" target="_blank">37</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198003#pone.0198003.ref043" target="_blank">43</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198003#pone.0198003.ref094" target="_blank">94</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198003#pone.0198003.ref097" target="_blank">97</a>].</p