Departamento de Zoologia, Universidade Federal do Rio de Janeiro, Instituto de Biologia, Avenida Carlos Chagas Filho, 373, Bloco A, Sala 074, Ilha do Fundão, Cidade Universitária, Rio de Janeiro, RJ, 21941-902, Brazil.
Departamento de Geologia, Universidade Federal do Rio de Janeiro, Instituto de Geociências, Avenida Athos da Silveira Ramos, 274, Bloco F, Ilha do Fundão Cidade Universitária, Rio de Janeiro, RJ, 21949-900, Brazil.
Sci Rep. 2021 Sep 27;11(1):19110. doi: 10.1038/s41598-021-97709-2.
Fossil microeukaryotes are key elements for understanding ancient ecosystems at microscopic level and improving the knowledge on the diversification of microbial life as a whole. We describe Palaeohypothrix bahiensis gen. et sp. nov., an exceptionally well-preserved Lower Cretaceous (Berriasian-Barremian; 145-125 Mya) amber-entrapped microeukaryote, identified as a spirotrich ciliate. The preservation of structures interpreted as the nuclear apparatus and remains of the ciliature revealed a novel ground plan, not found in modern Spirotrichea, thus representing a putatively extinct higher taxon lineage, viz. the Palaeohypotricha nov. tax. Based on cladistic analysis, the new taxon is hypothesized as phylogenetically related to the Protohypotrichia.
古微生物是理解古代微观生态系统的关键因素，并能整体提高对微生物生命多样化的认识。我们描述了一种保存非常完好的古微生物 Palaeohypothrix bahiensis 属和种，它来自早白垩世（巴列姆期到白垩纪早期；1.45 亿至 1.25 亿年前）的琥珀中，被鉴定为一种旋口虫类纤毛虫。结构的保存被解释为核器官和纤毛的残留物，揭示了一个新的基本模式，在现代旋口虫类中没有发现，因此代表了一个可能已经灭绝的高级分类群谱系，即古旋口虫类新分类群。基于系统发育分析，新分类群被假设与原始纤毛类具有系统发育关系。
