<div>The Cyclophyllidea comprise the most species-rich order of tapeworms
(Platyhelminthes, Cestoda) with, for helminths, perhaps the most severe
health impact on wildlife, livestock, and humans. Rodent biodiversity of
the Qinghai-Tibet Plateau (QTP) and its surrounding ranges provide a
significant reservoir for numerous species of Cyclophyllidea. We
collected cyclophyllidean species from QTP and Xinjiang province in
China, resolving four unsequenced and likely new species. Phylogenetic
construction of partial 18S rDNA, 28S rDNA and mitochondrial (
<i>mt</i>) genes provided high nodal support for the categorisation of
the three of the putative new species, assigning each respectively to
the genera <i>Hydatigera</i> (ex <i>Eospalax fontainierii</i>),
<i>Mesocestoides</i> (ex <i>Neodon irene</i>) and
<i>Paranoplocephala</i> (ex <i>Neodon irene</i>). Poor nodal support for
the unidentified (‘new’) species collected from pika ( <i>Ochotona
curzoniae</i>) in Yushu county, Qinghai province. Combined with the current
investigation, the other three cyclophyllidean species found in this
study ( <i>Taenia caixuepengi</i>, <i>Taenia crassiceps</i> and
<i>Versteria mustelae</i>) may be widely distributed in western China.
The phylogenetic reconstructions based on 28S rDNA and <i>cox</i>1-
<i>nad</i>1 indicate that some families and genera may require taxonomic
revision. Estimates of divergence time based on <i>mt</i> genes showed
that the differentiation rate of tapeworms was strongly associated with
the rate of change in the biogeographic scenarios caused by the uplift
of the QTP, i.e. species differentiation of Cyclophyllidea was driven by
host-parasite co-evolution caused by the uplift of QTP. We propose an
“out of QTP” hypothesis for the radiation of cyclophyllideans.</div>