Revisiting brachyuran crabs (Malacostraca: Decapoda) from Oligocene and Miocene fish beds of Europe

Outline analysis as a new method for investigating development in fossil crabs

“…The Liocarcinus data set contained 39 specimens (2 megalopae, 9 juveniles, 28 adults) from different extant and extinct populations. Recently, a specimen of Nautilograpsus prior (Smirnov, 1929) has been reinterpreted as a juvenile of L. oligocenicus (Hyžný et al, 2022). Using this case as an example, we tested four eligible specimens of L. oligocenicus from the original study, including the presumed juvenile in question, against the Liocarcinus data set, to see which category of developmental phase these specimens would be assigned to.…”

“…Considering the case of the representatives of L. oligocenicus (Hyžný et al, 2022), three of the four included specimens were originally identified as adults, one as juvenile. The discriminant function analysis identified one adult as juvenile and the suggested juvenile as adult.…”

“…We chose this species for its typical crab-like body and the knowledge of each specimen's developmental phase prior to investigation. We then test the method using a fossil relative, Liocarcinus oligocenicus (Paucă, 1929), of which some specimens may be juveniles (Hyžný et al, 2022).…”

Late Oligocene decapod crustaceans from the Trbovlje Formation of Slovenia, with a description of two new species of hymenosomatid crabs

“…The complete and articulated mode of preservation of hymenosomatid crabs indicates, that they likely represent corpses or a mix of corpses and moults (compare with Hyžný et al, 2022). Specimens would have been quickly buried in-situ, without any or a minimum post-mortem transportation or disturbance, and under calm, but rapid depositional conditions (Klompmaker et al, 2017).…”

Miocene and Pliocene amphibians from Hambach (Germany): new evidence for a late Neogene refuge in northwestern Europe

“…Decapod occurrences in Oligocene and lower Miocene fish beds (i.e., laminated marls yielding exceptionally preserved articulated fish fauna) of the Central and primarily Eastern Paratethys have been recognized since the beginning of the twentieth century (Paucă, 1929;Smirnov, 1929). These occurrences have recently been reassessed by Hyžný et al (2022) and Kovalchuk et al (2023).…”