How many species of fossil holothurians are there?

Here I offer a modern summary of crude fossil holothurian diversity (Figs. 1-3) and the most important localities (fossil lagerstätten; Table 1) of holothurian body fossils as a baseline for future research. Around

1 INTRODUCTION

Smiley (1994) and Kerr (2003) reported a total of more than 1,400 (1,427/1,430) valid species of Recent Holothuroidea. But how many species of fossil sea cucumbers are there? Older figures of ∼115 valid fossil holothurian species names can be culled from Durham (1954) and, some years later, Frizzell & Exline (1956, 1958) have catalogued 128 and respectively 153 fossil species. In the Treatise on Invertebrate Paleontology Frizzell & Exline

500 to 600 valid species can be probably recognised here from 948 published names (see appendix).