A new Early Oligocene crab (Decapoda, Brachyura, Dromiacea) from northwest Belgium, with comments on its palaeobiology

A new genus and species of dromiacean crab, Lucanthonisia praemium, is recorded from the basal Belsele- Waas Clay Member (Boom Clay Formation; Rupelian, lower Oligocene) as formerly exposed at the Scheerders van Kerchove (SVK) clay pit near Sint-Niklaas, province of Oost-Vlaanderen (northwest Belgium). Extant dromioid crabs either carry foreign objects for camouflage (Dromiidae, Homolodromiidae) or are associated with corals (Dynomenidae). Although having been collected from the basal portion of the Belsele-Waas Clay Member which is rich in phosphatic nodules, preservation of the new form is such that long-term transport is unlikely. Therefore, the species is assumed to have lived hidden amongst and below such nodules, but it cannot be ruled out that it also carried sponges for defence. To our knowledge, representatives of such biota have not yet been recorded from the Boom Clay Formation. Dromilites eotvoesi from middle Miocene (‘upper Badenian’, Serravallian) strata in the Budapest area (central Hungary) is transferred to the new genus, Lucanthonisia. Lucanthonisia eotvoesi n. comb. differs from L. praemium, the type species, in having shorter, more anteriorly directed lateral spines, more closely spaced and less divergent rostral horns, better-developed epigastric nodes and a less convex carapace longitudinally. Preservation of a partial thoracic sternum in L. praemium gen. nov., sp. nov. allows comparison with dromioid families and tentative placement of the new genus, as well as the allied Basinotopus, in the Dynomenidae

A new axiid (Crustacea: Decapoda: Axiidea) from the Neogene of Belgium and the Netherlands

From small phosphatic nodules in sandy deposits of Neogene age, previously excavated at Emblem (northwest Belgium) and currently suction dredged at Langenboom (southeast Netherlands), several chelipeds as well as fragments of carapace and abdomen of an axiid shrimp have been collected. These remains are here described as a new genus and species, which constitute the first record of the family Axiidae from Neogene strata in the North Sea Basin and the second species to be reported from Pliocene strata worldwide

[Proceedings of the 5th Symposium on Mesozoic and Cenozoic Decapod Crustaceans, Krakow, Poland, 2013: A tribute to Pál Mihály Müller / R.H.B. Fraaije, M. Hyžný, J.W.M. Jagt, M. Krobicki & B.W.M. van Bakel (eds.)]: New data on mid-Cretaceous dromioid crabs (Crustacea, Decapoda, Brachyura) from northwest Germany and southwest Iran

A single, slightly laterally compressed carapace of a dromioid crab from the middle/upper Albian part of the Kazhdumi Formation in the Hamiran area (Hormozgan Province, southwest Iran) is described as a new species, which is tentatively assigned to the brachyuran genus Distefania Checchia-Rispoli, 1917, D.(?) tangishirazensis. This constitutes the first record of the genus from the Middle East. In addition, from the long-defunct Rauen quarry at Kassenberg, near Mülheim-Broich (northwest Germany), a carapace of D. incerta and a rather battered cheliped of the ‘form genus’ Roemerus Bishop, 1983 are recorded from the upper Cenomanian portion of that section, thus adding to previous records of these taxa from Germany

The earliest record of a diogenid hermit crab from the Late Jurassic of the southern Polish Uplands, with notes on paguroid carapace terminology

A new species of diogenid paguroid, Eopaguropsis nidiaquilae, the earliest known member of the family to date, is recorded from sponge−reefal strata of Oxfordian (Late Jurassic) age in the southern Polish Uplands. Morphological features of the carapace suggest that the family Diogenidae diverged from other paguroid lineages such as the Pylochelidae and Parapaguridae, long before the Oxfordian Stage (161.2–155.7 Ma). The typically deep, V−shaped cervical groove of diogenids most likely was the product of fusion of the branchiocardiac and cervical grooves of their predecessors

The earliest record of pylochelid hermit crabs from the Late Jurassic of southern Poland, with notes on paguroid carapace terminology

Strata with cyanobacterial−sponge buildups of Middle to Late Oxfordian (Late Jurassic) age in the southern Polish Uplands document the earliest known members of the Pylochelidae. Two new Late Jurassic species of “symmetrical” hermit crabs, Ammopylocheles robertboreki and Jurapylocheles iwonae, are described. A new term, the massetic region, is introduced to describe the equivalent in paguroids of the hepatic region in brachyuran carapaces, because in the former, this region does not reflect the position of the liver but rather an attachment zone of the mandibular muscles

New Late Jurassic symmetrical hermit crabs from the southern Polish Uplands and early paguroid diversification

On the basis of carapaces, three new genera and species of symmetrical paguroid anomurans are described. Diogenicheles theodorae, Masticacheles longirostris, and Pilgrimcheles karolinae constitute the oldest known members of the family Parapylochelidae. As noted previously, assemblages from sponge−reefal strata of Oxfordian (Late Jurassic) age in the southern Polish Uplands document an important radiation event amongst paguroids. Compared to the present day, the Parapylochelidae were more diverse during the mid−Mesozoic; they appear to have withdrawn from shallow, reefal waters to deep−water settings from the Late Jurassic onwards. Paguroid faunas from the Oxfordian of Europe already are highly diverse, both morphologically and phylogenetically, and comprise early members of the families Diogenidae, Pylochelidae, and Parapylochelidae. This suggests that the evolutionary history of paguroids started much earlier (i.e., in pre−Jurassic times) than previously assumed. New terms for several typical paguroid carapace regions are introduced and on the basis of carapace morphology and ecological shifts hypotheses on the early speciation of hermit crabs are put forward

[Proceedings of the 5th Symposium on Mesozoic and Cenozoic Decapod Crustaceans, Krakow, Poland, 2013: A tribute to Pál Mihály Müller / R.H.B. Fraaije, M. Hyžný, J.W.M. Jagt, M. Krobicki & B.W.M. van Bakel (eds.)]: A new type of pylochelid sixth abdominal tergite (Anomura, Paguroidea) from the Upper Jurassic of Poland

Oxfordian (Upper Jurassic) siliceous sponge-microbial reef strata in the southern Polish Uplands around Kraków have recently yielded two types of sixth abdominal tergites of pylochelid paguroids. We here add a third one, Pylochelitergites exspectatus sp. nov. These small-sized, operculiform remains have a high preservation potential and thus allow us to document the geological history of two families of symmetrical hermit crabs, the Pylochelidae and Parapylochelidae, in some detail

[Proceedings of the 5th Symposium on Mesozoic and Cenozoic Decapod Crustaceans, Krakow, Poland, 2013: A tribute to Pál Mihály Müller / R.H.B. Fraaije, M. Hyžný, J.W.M. Jagt, M. Krobicki & B.W.M. van Bakel (eds.)]: A tribute to Pál Müller; his life, career and scientific output

An overview of Pál Müller’s 40-year palaeontological career is presented, inclusive of all decapod crustacean genera and species he erected, as well as those named after him, plus a complete listing of all papers devoted to axiideans, gebiideans, anomurans and brachyurans (co-)authored by Pál between 1974 and 2012