EARLY EVOLUTION AND NEW CLASSIFICATION OF THE ORDER ROBERTINIDA (FORAMINIFERA)

Abstract

The discovery of Triassic missing links in the Panthalassan domain (Wallowa terrane, U.S.A.) substantiates a direct lineage between internally simple Triassic multichambered aragonitic foraminifers and internally partitioned Jurassic Robertinida. A new hierarchical subdivision is accordingly proposed for the order Robertinida, which is emended to encompass all known post-Paleozoic aragonitic multicham-bered foraminifers. At the highest taxonomic level, the suborder Robertinina is distinguished from the suborder Duostominina emended to encompass forms without internal structures attached to the aperture, including the planktonic family Favusellidae and the controversial form Pragsoconu-lus. Two new families (Robertonellidae, Trochosiphoniidae), four new subfamilies (Cassianopapillariinae, Praereinholdel-linae, Pragsoconulinae, and Trochosiphoniinae), four new genera (Falsorheinoldella, Praerheinoldella, Robertonella, and Trochosiphonia), and seven new species (Falsorheinol-della ohmi, F. oregonica, Praerheinoldella galei, Robertonella rettorii, R. wallowensis, Trochosiphonia stanleyi, and T. josephi) are introduced. Phylogenetic links between Triassic robertinids, which experienced a rapid diversification during the Triassic, are clarified and their hypothetical long-term relationships with other foraminiferal groups are discussed.