The Earliest Record of Terrestrial Animals in Gondwana: A Scorpion from the Famennian (Late Devonian) Witpoort Formation of South Africa

Robert W. Gess

doi:10.5733/afin.054.0206

Abstract

The new genus and species, Gondwanascorpio emzantsiensis, are described in Scorpiones incertae sedis on the basis of fragments from the Famennian (Late Devonian) Waterloo Farm locality near Grahamstown, Eastern Cape, South Africa. This finding adds to the sparse record of Late Devonian scorpion taxa and provides the first evidence of Palaeozoic scorpions from Gondwana. Material includes a complete chela with associated patella as well as a telson with associated metasomal segment V, resembling those of the Mesoscorpionina. This is the first record of a scorpion occurring at high latitudes. Its close resemblance to contemporary taxa from Laurasia and China is consistent with evidence from the type locality for increasingly uniform terrestrial ecosystems by the end of the Devonian, characterised by cosmopolitan plant genera such as the progymnosperm tree Archaeopteris. In part, this may reflect increasing proximity between Laurasia and Gondwana towards the end of the Devonian. These specimens also provide the earliest record of terrestrial animals in Gondwana.

Highlights

Modern scorpions are an abundant group generally occurring in tropical and warm temperate regions worldwide, examples are known from cold high altitude environments in Patagonia
Terrestrialisation was believed to have occurred early in their history, probably during the Devonian period, with allegedly aquatic Proscorpiidae coexisting with terrestrial Mesoscorpionina and ‘palaeosterns’ until the early Carboniferous (Jeram 1998)
AFRICAN INVERTEBRATES, VOL. 54 (2), 2013 plication that the Araneae are not monophyletic (Scholtz & Kamenz 2006). This has been strongly refuted by Scholtz and Kamenz (2006) who argue that booklungs are an apomorphy of Araneae, that the Araneae are monophyletic and that they resulted from a single terrestrialisation event in their common stem lineage

Summary

INTRODUCTION

Modern scorpions are an abundant group generally occurring in tropical and warm temperate regions worldwide, examples are known from cold high altitude environments in Patagonia. This has been strongly refuted by Scholtz and Kamenz (2006) who argue that booklungs are an apomorphy of Araneae, that the Araneae are monophyletic and that they resulted from a single terrestrialisation event in their common stem lineage This implies that all fossil scorpions were primarily terrestrial. Palaeoscorpius devonicus Lehmann, 1944 from the Lower Devonian Hunsrück Slate Lagerstätte in Germany has been re-investigated (Kühl et al 2012) This key fossil was formerly interpreted as the most basal member of the Scorpiones and as one of the order’s most likely candidates for an aquatic mode of life (Jeram 1998). The Mesoscorpionina form the sister group of late Carboniferous Palaeopisthacanthus Petrunkevitch, 1913, the earliest member of the crown group (Jeram 1998). Legg et al (2009), suggest that mesoscorpions may be paraphyletic with regard to the crown group

MATERIAL AND METHODS

DISCUSSION