Denis Audo

Phylogeny of fossil and extant glypheid and litogastrid lobsters (Crustacea, Decapoda) as revealed by morphological characters

A phylogenetic analysis of a total of 31 species: 27 fossil species from seven families (Glypheidae, Litogastridae, Mecochiridae, Pemphicidae, Erymidae, Clytiopsidae, Chimaerastacidae), and four extant species from three families (Glypheidae, Nephropidae, Stenopodidae) is proposed. Most of the genera considered are coded exclusively based upon their type species and, as much as possible, based upon the type specimens. The cladistic analysis demonstrates that the glypheidean lobsters (infraorder Glypheidea) form a monophyletic group including two superfamilies: Glypheoidea and Pemphicoidea new status. Glypheoidea includes three families: Glypheidae, Mecochiridae and Litogastridae. Litogastridae is the sister group of the clade Glypheidae + Mecochiridae. Pemphicoidea includes a single family: Pemphicidae. A new classification of Glypheidea is proposed and currently known genera are rearranged based upon the phylogenetic analysis.

Middle Jurassic Monte Fallano Plattenkalk (Campania, southern Italy): first report on terrestrial plants, decapod crustaceans and fishes

A new Jurassic fossiliferous Plattenkalk has been discovered at Monte Fallano (Caserta, Campania, southern Italy). Biostratigraphic analyses indicate a Bajocian/Bathonian age (Middle Jurassic). The fossil assemblage consists of terrestrial plants, invertebrates (bivalves, gastropods, decapod crustaceans, isopods and insect larvae) and vertebrates (fishes). This study takes terrestrial plants, fishes, and decapod crustaceans into account, giving systematic, taphonomic and palaeoenvironmental considerations. The land flora consists of impressions of sterile and fertile shoots of microphyllous conifers; leaves with parallel venation of unknown taxonomy are also present. The genera Cupressinocladus, Brachyphyllum and Araucarites are documented and their microscopical characters are examined. Plant remains possibly represent a stable biotope, as floral composition presents no variation along the section studied. Taphonomic considerations on plant fossils suggest parautochtonous deposition. The study of the rich decapod crustacean fauna includes Acanthochirana liburiaensis n. sp. (Aegeridae Burkenroad, 1963), Casertanus sabellicus n. gen., n. sp. (Sergestidae dana, 1852), Eryma osciensis (Erymidae Van Straelen, 1925) and Tethyseryon campanicus n. gen., n. sp. (Eryonidae de Haan, 1841). Casertanus sabellicus n. gen., n. sp. is the oldest representative of Sergestidae in the fossil record, extending the stratigraphic range of this family into the Middle Jurassic. Tethyseryon campanicus n. gen., n. sp. is the earliest species in which juveniles have been identified within the Eryonidae; the presence of both juveniles and adults in the depositional environment of Monte Fallano suggests that this species was autochthonous or parautochthonous. Preliminary data on fossil fishes sample have lead to the identification of leptolepid, macrosemiid among which Notagogus (Neonotagogus) denticulatus, pleuropholid (Pleuropholis) and pycnodontid fishes; other primitive teleosts and incomplete and indeterminate “ganoid” fishes are also reported. Based on the sedimentological data and the characteristics of decapod crustaceans and fishes, the investigated record of the Monte Fallano section represents the product of depositional process in shallow water carbonate platform settings.

Late Cretaceous Crest-Bearing Shrimps from the Sahel Alma Lagerstätte of Lebanon

Decapod crustaceans are the most diverse group of fossil invertebrates from the Upper Cretaceous Sahel Alma Lagerstätte (Lebanon, Middle East). They are mainly represented by abundant crest-bearing shrimps which were first described as Penaeus libanensis. We review this species applying the new systematic nomenclature and we propose a more complete description based on 54 unpublished specimens. This review leads to the erection of Palaeobenthesicymus gen. nov. and to the new combination Palaeobenthesicymus libanensis that is the oldest record of the family Benthesicymidae. A neotype is herein designated. Detailed comparisons with extant analogues suggest that the crest bearing shrimps inhabited relatively deep water settings most probably exceeding 150 m, at the transition between the lower circalittoral and the upper bathyal zones, under dysphotic or aphotic conditions.

New eryonid crustaceans from the Late Jurassic Lagerstätten of Cerin (France), Canjuers (France), Wattendorf (Germany) and Zandt (Germany)

The Late Jurassic plattenkalks from Europe are remarkable for their exquisitely preserved crustaceans. New specimens of polychelidan lobsters (Crustacea, Decapoda, Polychelida) from the Lagerstätten of Cerin (France), Canjuers (France), Wattendorf (Germany) and Zandt (Germany) are described and increase the palaeobiodiversity of Jurassic eryonids. Soleryon gen. nov. is described from the Cerin, Wattendorf and Zandt Lagerstätten while Cycleryon bourseaui sp. nov. is described from the Cerin and Canjuers Lagerstätten. Soleryon amicalis gen. et sp. nov. from Cerin and S. schorri sp. nov. from Wattendorf show cephalothoracic grooves that are not observed within any other fossil eryonids. Their patterns of cephalothoracic grooves are similar to those observed in extant polychelids and confirm the affinities of eryonids and polychelids. The problematic assignment of Eryon perroni Étallon, 1859 from the Oxfordian nodules of eastern France is solved and leads to the new combination Soleryon perroni (Étallon, 1859). These new eryonids are preserved in anatomical connection and thus suggest they used to live in proximity to their depositional environments. They may have inhabited the coral reefs neighbouring the lagoons and/or buried themselves in the carbonate mud of the lagoon margins at the origin of the plattenkalks. The co-occurrences of Soleryon gen. nov. and Cycleryon Glaessner, 1965 in four subcontemporaneous Lagerstätten clearly suggest connections between the Bavarian (Wattendorf, Zandt), the Jura (Cerin) and the Provence (Canjuers) platforms. For the first time, several species of crustaceans highlight and confirm the palaeobiogeographical links between the French and German plattenkalks at the end of the Jurassic. http://zoobank.org/urn:lsid:zoobank.org:pub:76AD86C3-C677-49EA-B742-0ACA6EB90F72

Diversity of developmental patterns in achelate lobsters—today and in the Mesozoic

Modern achelate lobsters, slipper and spiny lobsters, have a specific post-embryonic developmental pattern with the following phases: phyllosoma, nisto (slipper lobsters) or puerulus (spiny lobsters), juvenile and adult. The phyllosoma is a peculiar larva, which transforms through a metamorphic moult into another larval form, the nisto or puerulus which largely resembles the juvenile. Unlike the nisto and puerulus, the phyllosoma is characterised by numerous morphological differences to the adult, e.g. a thin head shield, elongate appendages, exopods on these appendages and a special claw. Our reinvestigation of the 85 million years old fossil “Eryoneicus sahelalmae” demonstrates that it represents an unusual type of achelatan lobster larva, characterised by a mixture of phyllosoma and post-phyllosoma characters. We ascribe it to its own genus: Polzicaris nov. gen. We study its significance by comparisons with other cases of Mesozoic fossil larvae also characterised by a mixture of characters. Accordingly, all these larvae are interpreted as ontogenetic intermediates between phyllosoma and post-phyllosoma morphology. Remarkably, most of the larvae show a unique mixture of retained larval and already developed post-larval features. Considering the different—and incompatible—mixture of characters of each of these larvae and their wide geographical and temporal distribution, we interpret all these larvae as belonging to distinct species. The particular character combinations in the different larvae make it currently difficult to reconstruct an evolutionary scenario with a stepwise character acquisition. Yet, it can be concluded that a larger diversity of larval forms and developmental patterns occurred in Mesozoic than in modern faunas.

New Nisto of Slipper Lobster (Decapoda: Scyllaridae) from the Hadjoula Lagerstätte (Late Cretaceous, Lebanon)

ABSTRACT Slipper lobsters (Decapoda: Scyllaridae) are rather rare in the fossil record. The exceptionally well-preserved scyllarid decapod described herein comes from the Late Cretaceous Hadjoula Lagerstätte, Lebanon. This new specimen represents the first fossil “postlarval” stage (nisto) described, and it is assigned with confidence to Arctidinae. Converging lines of evidence from the depositional environment and comparisons with modern analogues indicate that this nisto probably lived in small intra-shelf basins before migrating to shallow-water conditions during the adult stage.

High biodiversity in Polychelida crustaceans from the Jurassic La Voulte-sur-Rhône Lagerstätte

ABSTRACT The Middle Jurassic La Voulte-sur-Rhône Lagerstätte preserves with remarkable details a highly diversified bathyal palaeocommunity dominated by arthropods. Polychelida Scholtz & Richter, 1995 are particularly abundant and are currently represented by Eryon ellipticus Van Straelen, 1923, Proeryon giganteus (Van Straelen, 1923), Hellerocaris falloti (Van Straelen, 1923), and Willemoesiocaris ovalis (Van Straelen, 1923). This new investigation reveals the presence of two new genera and three new species in this crustacean community: Voulteryon parvulus n. gen., n. sp., Cycleryon romani n. sp., which is the oldest occurrence of the genus, and Adamanteryon fourneti n. gen., n. sp., an enigmatic polychelidan of uncertain affinities. The genus Proeryon Beurlen, 1928 is also revised to solve problems of homonymy, and as a consequence we here propose the replacement name Proeryon zehentbaueri pro Proeryon giganteus Beurlen, 1930, non Proeryon giganteus (Van Straelen, 1923). These new results place the La Voulte polychelidan lobster community at the first rank in terms of familial and generic diversity (three families, seven genera) and at the second rank in terms of species diversity (seven species) just after the Late Jurassic Eichstätt Lagerstätte (eight species). Thanks to modern techniques, such as X-ray tomography, this study also documents structures never observed before such as thoracic appendages of Proeryon giganteus and Hellerocaris falloti. In the case of Hellerocaris falloti, these new observations suggest it is one of the closest fossil relatives to extant polychelids.

New look at the lobster Eryma greppini, Oppel, 1861 (Crustacea, Decapoda, Erymidae) from the Middle Jurassic of France and Switzerland

Erymid lobsters (Decapoda, Erymidae) are a relatively abundant family of decapod crustaceans with a presumed conservative morphology. For these reasons, numerous species of erymids have been synonymized with others by early efforts to review the family. Eryma greppini Oppel, 1861, is one of these. A well-preserved specimen of erymid lobster assigned to this species has recently been traced in the palaeontological collections from the Université Claude Bernard Lyon 1 (France). Study of this specimen and examination of the type material of Eryma greppini, Eryma affinis Ferry, 1865, and Eryma bedeltum (Quenstedt, 1857) lead us to consider Eryma greppini to be a valid species, characterized by a peculiar pair of dorsal domes. A lectotype is herein designated for Eryma greppini. This study is a first step toward the necessary revision of erymid lobsters and proves the importance of taxonomic studies based on type material.

First occurrence of Ibacinae (Eucrustacea: Decapoda: Scyllaridae) from the Eocene of Pakistan

The fossil record of slipper lobsters (Scyllaridae) is very poor, even though the earliest species of the modern slipper lobsters (Neoscyllaridae) are known from the Early Cretaceous. Among the clades (‘subfamilies’) of slipper lobsters, perhaps the most remarkable is Ibacinae (currently monogeneric), which contains species with a very wide carapace (cephalothoracic shield) and very deep incisions. Fossil species assigned to Ibacinae were reported from the Oligocene and Pleistocene. However, a recent reappraisal of Scyllaridae phylogeny revealed that the genus to which these two fossil occurrences belong is not closely allied to Ibacinae. Therefore, Ibacinae was left with no known fossil record until the present study. The present study describes a new species, which can be confidently assigned to Ibacinae (closely allied to Ibacus), from the Ypresian (early Eocene) of the Ghazij Formation in Shaisuro, Dera Ghazi Khan District, Pakistan. This new species, Ibacus? mazariorum sp. nov., corresponds to the oldest recorded occurrence of Ibacinae. The Ghazij Formation was deposited on the north-western margin of the India-Pakistan plate during a critical period, shortly before the collision between the India-Pakistan plate and Asia. Consequently, it is possible that Ibacus and closely allied species may have remained in the same biogeographical area since the Eocene. Considering the extant and fossil distribution of Ibacinae, additional fossil discoveries may be found in existing collections and fossiliferous outcrops from the Neotethys, Indian and Pacific oceans. http://zoobank.org/urn:lsid:zoobank.org:pub:84F54514-AA21-4A9D-91CA-BDCACBA5F4F8