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A – geographical position of the locality and simplified geological sketch of Eocene strata of Istria (after Živkovic & Glumac 2007). @BULLET B – stratigraphical column indicating the level of provenance of Lessinipagurus vasjamikuzi sp. nov.
Source publication
A paguroid, Lessinipagurus vasjamikuzi sp. nov., is described from Eocene (upper Bartonian-lower Priabonian) of Istria, on the basis of a single right chela from Gračišće near Pazin, western Croatia. The specimen originates from beds of olistostrome breccias that formed in a bathyal setting. In addition, a new genus, Prexylopagurus, accommodated in...
Contexts in source publication
Context 1
... Eocene strata in Istria comprise a clastic flysch sequence and pelagic foraminiferal limestones (Fig.1A). The majority of known macrofossil localities are situated around the contact of both lithologies (Mikuž et al. 2014), where the foraminiferal limestones grade into the flysch and are therefore called "Transitional Beds". ...
Context 2
... with Crabs" are interpreted to reflect a gradual deepening from a shelf carbonate platform to bathyal environments ( Juračić 1979Juračić , Ćosović et al. 2004). The upper part of these beds consists of several tens of metres of hemipelagic Globigerina marls, which are conformably overlain by coarser flysch beds, including the olistostrome breccia (Fig. 1B) discussed herein (Marinčić et al. ...
Citations
... These species occur at depths ranging from a few metres (X. cancellarius) to several hundreds of metres (Forest 1997;Gašparič et al. 2016). ...
... Lastly, chelipeds are markedly dissimilar, the strong, massive right cheliped having a 'pseudo-fixed' finger that runs parallel to the outer side of the dactylus. The combination of these features warranted the erection of a new paguroid family, Xylopaguridae, by Gašparič et al. (2016). ...
... As noted above, this probably is the oldest record of this peculiar group of paguroids. On the basis of the presence of a long decalcified submassetic groove, a new generic name was coined by Gašparič et al. (2016) to accommodate the Recent species X. anthonii, X. philippinensis and X. caledonicus that all have a submassetic groove. The genus Xylopagurus comprises species without such a groove. ...
Xylopagurids constitute an enigmatic group of marine paguroid anomurans that comprises both extinct and extant genera, such as the middle Eocene (Lutetian) Pacific and Indo-West Pacific oceans. The first appearance and subsequent radiation of xylopagurids during the middle and late Eocene parallels the origin and rapid global expansion of larger grasses such as reed and bamboo. The functional morphology of xylopagurid chelae as adaptation to inhabiting empty bamboo shoots is discussed. This is the first documented example of a link between terrestrial plants and marine decapod crustaceans, illustrating that a novelty on land could have had a significant impact on ecological opportunities in the marine domain.
... schWeigert et al. (2013) erected a new family, Schobertellidae, to accommodate taxa from Lower Jurassic shallow-shelf strata. Recently, Gašparič et al. (2016) andFraaije et al. (2017b) erected new paguroid families. ...
Following several studies of anomuran (galatheoid) and brachyuran decapod crustaceans during recent years, we here present the first account of hermit crab carapaces and/or shields (Paguroidea) that are contained in the extensive Ernstbrunn Limestone collections at the Naturhistorisches Museum Wien (Vienna, Austria). These comparatively small-sized specimens are assignable to the families Annuntidiogenidae, Diogenidae, Gastrodoridae, Paguridae, Parapylochelidae, Pilgrimchelidae, Pylochelidae and Schobertellidae.With at least 18 species, in eight families, the Tithonian (Late Jurassic) paguroid fauna from Ernstbrunn is by far the most diverse extinct assemblage recorded to date. For the first time, Jurassic representatives of the family Paguri-dae are described on the basis of carapaces. Most of the material available was collected or obtained and recognised as paguroid in nature by one of us (FB) in the 1940s to 1960s. Unfortunately , the opportunity to describe these formally never presented itself to FB, despite the fact that typescripts on numerous new species were ready to be published. The majority of specimens, photographs and typescripts, recently rediscovered, form the basis of the present study. Species recorded here, in alphabetical order, are: Ammopylocheles mclaughlinae, Annuntidiogenes elon gatus nov. spec., An. hoelderi nov. spec., Bachmayerus gasparici nov. spec., B. matushyznyi nov. spec., Cretatrizocheles doerflesensis nov. spec., Eopaguropsis grandis nov. spec., E. schindewolfi nov. spec., Gastrodorus spp., Masticacheles minimus, Mesoparapylocheles strouhali nov. spec.,
The origin and function of peculiar mushroom-shaped cuticular structures in some decapod crustaceans remains unknown. This ornamentation has appeared several times in widely disparate clades (in podotreme and heterotreme crabs, and pagurids). These structures are analysed in the modern genus Daira and compared with fossil material from the Eocene of Huesca and the Miocene of Alicante and Mallorca. A morphological and petrographic study is carried out using conventional microscopy and Scanning Electron Microscopy to understand the microstructure in modern and fossil representatives. This provides a clear view of the mushroom-like structures that cover the carapace of Daira and the distribution of the different layers of the exoskeleton. The results reveal a complex morphology, which involves all layers of the cuticle, with changes in the thickness of the exocuticle in different areas, and the presence of conical structures that especially affect the outer layers. These convolutions form a network of channels connected to the outside by pores. Finally, possible anti-predatory functions of these complex structures are proposed.
In our ongoing studies of both extinct and extant hermit crabs (Paguroidea Latreille, 1802), we have observed and recorded a number of morphological changes that have taken place between Early Jurassic times (c. 185 million years ago) and the present day. Species compositions of paguroid assemblages from marine Upper Jurassic and Lower Cretaceous rocks in Europe are here compared with those of modern marine settings. Basal paguroids with cylindrical carapaces predominated in reefal environments during the Late Jurassic, but were gradually replaced by hermit crabs with non-cylindrical carapaces.
The most basal paguroids reveal a branchial groove, but branchial condensation towards a single (i.e., cervical) groove is here shown to have occurred early in their evolutionary history. In several extant, genera remnants of a branchial groove, in combination with several other basal features, can be seen.
For this reason, these are here considered to be the most primitive members amongst extant paguroids. In this study, we resurrect the family Probeebeidae and erect a new family, Paguropsidae n. fam, to accommodate extant basal hermit crabs such as Paguropsis Henderson, 1888, Eopaguropsis Fraaije, Krzemiński, Van Bakel, Krzemińska & Jagt, 2012 and Paguropsina Lemaitre, Rahayu & Komai, 2018. Described are also one pair of Early Jurassic (Pliensbachian) and two pairs of Middle Jurassic (Callovian) isochelous paguroid chelae, all collected recently. A new specimen of Schobertella reveals
some important morphological traits of the shield that had not been observed previously. The earliest known example to date of clearly heterochelous chelae in the fossil record of hermit crabs originates from upper Kimmeridgian/Tithonian strata in the Boulonnais (northwestern France). For the first time, a phylogenetic scheme of marine Paguroidea, as based on morphological data of carapaces, is presented.
A new, carapace-based species of paguroid is recorded from lower Kimmeridgian (Planula ammonite zone) limestones exposed at the Plettenberg quarry (Dotternhausen). The calcified posterior carapace, the mesogastric process with a median ridge, the pronounced rostrum and coarse ornament are indicative of placement in the genus Daciapagurus Franţescu, Feldmann, Schweitzer, Lazăr & Stoica, 2018 and the family Schobertellidae Schweigert, Fraaije, Havlik & Nützel, 2013. Daciapagurus suebiorum n. sp. is the second member of the genus known to date, extending its palaeobiogeographical distribution and stratigraphical range.
