Introduction

Abstract

The raison d’être of paleobiology is the reconstruction and explanation of past life based on fossil evidence. This cannot be accomplished without first describing the main structural characters of fossil taxa. We will describe and analyze the characters of Fisherites orbis from the Swedish Island of Öland (originally described as Receptaculites orbis by Eichwald 1840a) within the larger framework of Problematica, that is, fossil taxa that cannot be assigned into any classificatory scheme because their phylogeny is unknown. We will briefly review the history of interpretations of the nature of receptaculitids, and by combining historical analysis with morphological analysis, attempt to lay the foundation for the future reconstruction of the phylogeny and systematic position of receptaculitids.