Wiedopterus

Wiedopterus was a relatively small eurypterid, with the only described fossil specimen, measuring 4.43 centimeters (1.74 in) in length, accounting for a little over half of the animal. If Wiedopterus was an adelophthalmoid, it would be a medium-sized member of the group, whose members ranged in length from 4 to 32 centimeters (1.6 to 12.6 in). The diagnostic features of the genus, as noted by Poschmann in its description, include the carapace (head plate) being shaped like a trapezoid and having a narrow marginal rim, the compound eyes being placed close to the center of the carapace, the preabdomen (body segments 1–7) being rounded and wide, with the anteriormost (most forwardly placed) tergite being reduced in size, the tergites possessing narrow anterior articulation facets, the dorsal (back) preabdomen not having any prominent ornamentation, and that there is a marked constriction between the preabdomen and the postabdomen (body segments 8–12). The preabdomen of Wiedopterus was widest at the third or fourth segment, where it measured about 2.05 centimeters (0.81 in) in width. == History of research ==

Wiedopterus noctua was described by Poschmann in 2015 based on a single specimen recovered in fossil deposits of Early Devonian, probably Emsian, age. The fossil locality, part of the Rhenish Massif, is a wayside outcrop located next to a bus stop, about 500 meters north of the village Bürdenbach and 90 meters northeast of the confluence of the small creek Güllesheimer Bach and the Lahrbach river. The species name noctua is Latin for "owl" and derives from Poschmann finding the carapace and the eyes of Wiedopterus to be "somewhat reminiscent of an owl". == Classification ==

Wiedopterus is different from other known Early Devonian eurypterids when it comes to the position of its compound eyes and the shape of its carapace. Moselopterus, Alkenopterus, Vinetopterus and Erieopterus are superficially similar, but Moselopterus, Alkenopterus and Vinetopterus all have a more horseshoe-shaped carapace, with the carapace of Moselopterus also has distinct ornamentation, missing in Wiedopterus, and Alkenopterus and Vinetopterus have wider and differently shaped, respectively, marginal rims. Erieopterus has a more rounded carapace, with the eyes positioned more outwardly. The shape and eye position is also similar to the Silurian Eurypterus (though the carapace of Eurypterus is slightly more quadratic, the eyes are positioned further back and its first opisthosomal tergite is not as small), the Silurian Buffalopterus and the Silurian–Devonian Strobilopterus (though Buffalopterus and Strobilopterus have a wider carapace and eyes positioned further back).''' == Paleoecology ==

The fossil deposits in which the Wiedopterus type specimen was found were once a land–sea transitional area, featuring rivers, deltas and fully marine environments, where the fossils were deposited under rapid environmental changes. Other fossil life known from the same deposits include jawless fish (Rhinopteraspis), trigonotarbids (Spinocharinus and Archaeomartus), scorpions (Waeringoscorpio), chasmataspidids, bivalves and other eurypterids (Parahughmilleria). Also present were early land plants, most prominently Zosterophyllopsida. == See also ==