''Liassoscorpionides'' is an extinct genus of scorpions from the
Toarcian
The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian.
The Toarc ...
of Germany. It was found on the
Posidonia Shale
The Posidonia Shale (german: Posidonienschiefer, also called Schistes Bitumineux in Luxembourg) geologically known as the Sachrang Formation, is an Early Jurassic (Toarcian) geological formation of southwestern and northeast Germany, northern Swi ...
, on the so-called insect beds of
Hondelage near
Braunschweig
Braunschweig () or Brunswick ( , from Low German ''Brunswiek'' , Braunschweig dialect: ''Bronswiek'') is a city in Lower Saxony, Germany, north of the Harz Mountains at the farthest navigable point of the river Oker, which connects it to the Nor ...
, on a layer, as its name suggests, full of insect genera. ''Liassoscorpionides'' is the only confirmed jurassic scorpion discovered.
[
The holotype consists of a partial body fossil, measuring 14.4 mm in length and 4.8 mm in width.][Bode, A. (1951). Ein liassischer Scorpionide. Paläontologische Zeitschrift, 24(1-2), 58-65.] The preserved elements include a thin, short postabdomen (¼ metasoma), granulation of the carapace (¼ dorsal shield of the Prosoma
The cephalothorax, also called prosoma in some groups, is a Tagma (biology), tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. (The terms ''prosoma'' and ''opisthosoma'' are equiv ...
), ornament on the posterior tergite margins resembling hatching, and a weak and delicate pedipalpal claw (supposedly superimposed from beneath the body). A median gut trace and a feature representing either a ''Runzelung'' (wrinkle) or a stigma (¼ spiracle) on the margin of at least the fifth Mesosomal segment was described, but its presence is controversial.[Dunlop, J. A., Kamenz, C., & Scholtz, G. (2007). Reinterpreting the morphology of the Jurassic scorpion Liassoscorpionides. Arthropod structure & development, 36(2), 245-252.] Later, the original material was restudied and resolved numerous new features.
Being the only Jurassic scorpion known, there is no evidence that L. schmidti was aquatic (which was suggested in the past) and in the absence of further, better preserved material it should be excluded from future considerations of broad patterns of scorpion evolution. Some works consider it even a nomen dubium.[Stockwell, S.A., 1989. Revision of the phylogeny and higher classification of the scorpions (Chelicerata). Ph.D. thesis, University of California, Berkeley.] With the spider '' Seppo koponeni'' is one of the two only known arachnids from the Lower Jurassic of Germany.
References
Prehistoric scorpions
Prehistoric arachnid genera
Scorpion genera
Jurassic arthropods
Jurassic arachnids
Jurassic Germany
Fossils of Germany
Posidonia Shale
Fossil taxa described in 1951
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