Metrics details. Paleozoic scorpions Arachnida: Scorpiones have been widely documented from the Carboniferous Period; which hosts a remarkable assemblage of more than sixty species including both putative stem- and crown-group fossils. By contrast the succeeding Permian Period is almost completely devoid of records, which are currently restricted to a trace fossil from the early Permian of New Mexico, USA and some limb fragments from the late Permian of the Vologda Region, Russia.
Opsieobuthus tungeri sp. Explosive volcanism preserved these remarkable specimens in situ as part of the palaeosol horizon and bedrock of the Petrified Forest, immediately beneath the Zeisigwald tuff horizon. This dates to the early Permian Sakmarian or ca.
Intriguingly, the specimens were obtained from a palaeosol horizon with a compacted network of different-sized woody roots and thus have been preserved in situ in their likely life position, even within their original burrows. Differences in the structure of the comb-like pectines in the two fossils offer evidence for sexual dimorphism, and permit further inferences about the ecology and perhaps even the reproductive biology of these animals.
As putative members of a Coal Measures genus, these fossils suggest that at least some Carboniferous scorpion lineages extended their range further into the Permian. This contributes towards a picture of scorpion evolution in which both basal and derived orthostern forms coexisted for quite some time; probably from the end of the Carboniferous through to at least the mid Triassic.
Scorpions are iconic arachnids with over two thousand living species distributed across eighteen different families [ 1 ]. They are also characterized by a fairly extensive fossil record, which extends back to at least the mid Silurian ca. At present there are valid species of fossil scorpion [ 3 ], although their distribution through time is far from homogeneous [ 4 ]. In particular, the Carboniferous Period ca.
