06 September, 2013

A very old scorpion

The pincer and metasomal segments of the ancient scorpion of Gondwana (Photos: University of Witwatersrand (C))

Scorpions are a very old group dating back to the early Silurian period. Robert Gess has now described one of the oldest fossil scorpions and the earliest record of a terrestrial animal in Gondwana.

Gondwanascorpio emzantsiensis Gess, 2013

An interesting point in this article is that reexaminations of other early fossils of scorpions point in the direction of the early scorpions being terrestrial and not aquatic (as believed by some authors).

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.

Gess RW. The earliest record of terrestrial animals in Gondwana: A scorpion from the Famennian (Late Devonian) Witpoort Formation of South Africa. African Invertebrates. 2013;54(2):373-9. [Free full text]

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