Organism · Arthropods
Pseudastacus pustulosus
Source time context (not species duration) · ≈ 201–143 Ma
Inferred life reconstruction
Pseudastacus pustulosus
Overview
Pseudastacus pustulosus is a crustacean known from Late Jurassic lithographic limestones. Grooves in the carapace covering the head and thorax and the end of the tail provide research clues. Its crayfish-like appearance introduces crustaceans of Jurassic lithographic limestones.[1][2]
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Key facts
Carapace grooves are not simply decorations. A broad main groove curving slightly like an S and weak branching grooves were described in this species. Such small differences preserved in thin rock provide clues for comparing similar crustaceans.[1]
Time and place
It is known from Late Jurassic strata around 150 million years old. Important specimens came from the lithographic limestones of Eichstätt and Solnhofen in present-day Bavaria, Germany. This region is also famous for pterosaurs and many other fossils.[1]
The time range describes source context, not the complete duration of this species.
Size, form and skeleton
The abdomen and tail follow the carapace covering the head and thorax. The carapace has a broad main groove, and the central terminal part of the tail is described as solid and undivided. Large claws and a posterior tail fan stand out in historical whole-body comparisons.[1][2]
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Habitat and reproduction
Could crustaceans with different names actually represent males and females? In an abstract for the 2005 Eichstätt conference, Garassino and Schweigert interpreted Pseudastacus muensteri as the female of pustulosus. This research reconsidered differences in names and forms as a question of sex.[1][2][3]
Fossil discovery
Albrecht compared several specimens held in Munich in 1983. Among them, AS I 669 was a specimen addressed by Oppel in 1861. An exposed mandibular joint was interpreted as having been pressed through the carapace during burial, also revealing the process of fossilization.[1]
References
Research questions
Are lines preserved on the carapace original body structures or changes produced during burial? Researchers compare grooves, joints, and overlapping shell parts. Reexamining the same specimen allows classification and preservation processes to be studied together.[1]
Observation
Move your gaze from the large claws to the carapace of the head and thorax, then to the abdomen and tail fan. Imagining the curved grooves in the carapace brings closer the research that distinguishes animals through small features.[1][2]
Related organisms
Rhamphorhynchus muensteriArchosaursSource time context (not species duration) · ≈ 201–143 MaDifferent fossils encountered at Solnhofen
Pseudastacus and Rhamphorhynchus are known from Jurassic fossils of the Solnhofen region in present-day Germany. Examining a crustacean and a pterosaur together reveals the diversity preserved at this locality.