Reassessment of the type collections of Maslov’s species of Corallinales (Rhodophyta). I. species originally attributed to Lithophyllum and Melobesia

Resumo

This paper is part of a wider project for reassessing Maslov’s original collection of fossil calcareous algae with a modern taxonomic approach. Based on this collection, currently housed in the Geological Institute of the Russian Academy of Sciences of Moscow, Maslov described many taxa of calcareous algae of diverse ages from the former USSR in two monographs and several other papers from 1929 to 1973. As in other taxonomic publications from those decades, many of Maslov’s new species of fossil coralline algae were distinguished by only a few characters of questionable taxonomic significance; in addition, most of his work was published in Russian with limited illustrations. This study deals in particular with Maslov’s original preserved material of species attributed by him to the genera Lithophyllum and Melobesia (Corallinales, Rhodophyta). Our reassessment indicates that only the types of Lithophyllum duplex Maslov, and Hydrolithon corculumis (Maslov) comb. nov. (= Lithophyllum corculumis) show significant features justifying their use as species names in coralline algal taxonomy. The type of Lithophyllum microsporum Maslov is a gametangial plant that cannot be compared with the tetrasporangial plants used to delimit other coralline algal species within the Corallinaceae subfamily Lithophylloideae. Although they are validly published species names, the lack of significant characters in the preserved types prevents any confident placement of “Melobesia (Lithoporella) badjii”, “Lithophyllum conocristatum”, “L. dioscurensum”, “M. (L.) karpatica” “L. (Tenarea?) lithothamnioides”, “L. pavlovii”, “L. platticarpum”, “L. premoluccense var. cretacicum”, “L. senonicum”, “L. translucidum” in any defined generic or suprageneric taxon within the Corallinales.