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The ecological and physiological significance of body size is well recognized. However, key macroevolutionary questions regarding the dependency of body size trends on the taxonomic scale of analysis and the role of environment in controlling long-term evolution of body size are largely unknown. Here, we evaluate these issues for decapod crustaceans, a group that diversified in the Mesozoic. A compilation of body size data for 792 brachyuran crab and lobster species reveals that their maximum, mean and median body size increased, but no increase in minimum size was observed. This increase is not expressed within lineages, but is rather a product of the appearance and/or diversification of new clades of larger, primarily burrowing to shelter-seeking decapods. This argues against directional selective pressures within lineages. Rather, the trend is a macroevolutionary consequence of species sorting: preferential origination of new decapod clades with intrinsically larger body sizes. Furthermore, body size evolution appears to have been habitat-controlled. In the Cretaceous, reef-associated crabs became markedly smaller than those in other habitats, a pattern that persists today. The long-term increase in body size of crabs and lobsters, coupled with their increased diversity and abundance, suggests that their ecological impact may have increased over evolutionary time., (© 2015 The Author(s) Published by the Royal Society. All rights reserved.)

Lobsters are a ubiquitous and economically important group of decapod crustaceans that include the infraorders Polychelida, Glypheidea, Astacidea and Achelata. They include familiar forms such as the spiny, slipper, clawed lobsters and crayfish and unfamiliar forms such as the deep-sea and "living fossil" species. The high degree of morphological diversity among these infraorders has led to a dynamic classification and conflicting hypotheses of evolutionary relationships. In this study, we estimated phylogenetic relationships among the major groups of all lobster families and 94% of the genera using six genes (mitochondrial and nuclear) and 195 morphological characters across 173 species of lobsters for the most comprehensive sampling to date. Lobsters were recovered as a non-monophyletic assemblage in the combined (molecular + morphology) analysis. All families were monophyletic, with the exception of Cambaridae, and 7 of 79 genera were recovered as poly- or paraphyletic. A rich fossil history coupled with dense taxon coverage allowed us to estimate and compare divergence times and origins of major lineages using two drastically different approaches. Age priors were constructed and/or included based on fossil age information or fossil discovery, age, and extant species count data. Results from the two approaches were largely congruent across deep to shallow taxonomic divergences across major lineages. The origin of the first lobster-like decapod (Polychelida) was estimated in the Devonian (∼409-372 Ma) with all infraorders present in the Carboniferous (∼353-318 Ma). Fossil calibration subsampling studies examined the influence of sampling density (number of fossils) and placement (deep, middle, and shallow) on divergence time estimates. Results from our study suggest including at least 1 fossil per 10 operational taxonomic units (OTUs) in divergence dating analyses. [Dating; decapods; divergence; lobsters; molecular; morphology; phylogenetics.]., (© The Author(s) 2014. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved.For Permissions, please email: journals.permissions@oup.com.)

Extinction and origination of genera and families of marine Decapoda at the end of the Cretaceous established the modern fauna. Podotrematous crabs suffered high extinction levels, whereas heterotrematous crabs experienced both extinction and radiation. Anomuran decapods exhibited high extinction levels at the generic but not family level. In general, family extinctions predominantly occurred among podotrematous and heterotrematous crabs, which also exhibit overall shorter family ranges. Possible refugia promoted survival of genera and families into the Paleocene, whereas habitation of the Western Interior Seaway ensured high levels of extinction. Areas proximal to the Chicxulub impact site experienced moderate levels of extinction. Habitat specialists preferentially survived the end-Cretaceous extinction in some clades. Heterotrematous crabs recovered rapidly in the Paleocene, especially in the siliciclastic environments of the Americas. Because decapod crustaceans are highly variable in morphology, habitat, and ecology, no one pattern of extinction and recovery can explain the end-Cretaceous decapod extinction event. Rather, a mosaic of responses in various decapod groups led to their differential survival. [ABSTRACT FROM AUTHOR]

New decapod crustaceans from ?Selandian to Thanetian strata of the Kambühel Formation, Austria, include the paguroid Squamipelta insecta new genus and species, and two new galatheoid species, Protomunida kambuehelensis and Annieporcellana paleocenica. The range of Annieporcellana is extended across the Cretaceous-Paleogene boundary. Selandian and Thanetian decapod occurrences are rare; thus, this report adds to the known decapod diversity in the recovery after the end-Cretaceous events. [ABSTRACT FROM AUTHOR]

New brachyuran species from the ?Selandian to Thanetian units of the Kambühel Formation include Dromiopsis bullamelga, Dromiopsis aedicula, and Braggicarpilius wanzenboecki. Four previously named brachyuran species are also present. Carpiliidae is both the only extant family present and the only family represented in the Kambühel Formation to originate after the end-Cretaceous. Half of the genera present in the Kambühel Formation (Dromiopsis, Caloxanthus, and Titanocarcinus) survived the end-Cretaceous mass extinction event, and all of the surviving genera originated during the Cretaceous. All of the identified species originated in the Paleocene. 87.5 % of species and 95 % of individual specimens found by two of us (RMF, CES) in one day of collecting at Fakse Quarry are podotrematous, while 80 % of species and 46 % of individual specimens found in the Kambühel Formation are podotrematous. The specimens from the Kambühel Formation suggest that by late Paleocene time, biomass of the heterotremes surpassed that of the podotremes. [ABSTRACT FROM AUTHOR]

Faunal turnover is a pattern of diversification and extinction in taxa throughout the geologic record. Patterns of repeated faunal turnovers are referred to as faunal progression, demonstrated by Decapoda in clawed lobsters and podotrematous and heterotrematous crabs. The transition between podotrematous and heterotrematous crabs is the most recent. Among these, section Raninoida Ahyong, Lai, Sharkey, Colgan & Ng, 2007, commonly called "frog crabs," constitutes a major monophyletic group with podotrematous body forms, and the focus of our study. Declines in raninoidan diversity were aligned with mass extinction events and major climate shifts, especially cooling. Likewise, diversification within Raninoida occurred in warm, greenhouse climates. Thus, a major factor in patterns of faunal turnover in Decapoda is shown to be environmental conditions. Raninoidan families exhibiting adaptations facilitating back-burrowing preferentially survived the end-Cretaceous mass extinction event, whereas raninoidans lacking such adaptions did not go completely extinct at the end-Cretaceous but failed to recover diversity. Given the diversification of heterotrematous crabs into a wide variety of ecological niches throughout the Cenozoic, competition may be a secondary, but still crucial, factor in this faunal turnover. [ABSTRACT FROM AUTHOR]

Several hundred specimens of the crab Dakoticancer overanus Rathbun, 1917 represent a normal size-distributed adult population, with a skewed sex ratio of 21% females to 79% males. Sexual dimorphism is clearly developed in the shape of the sternum and pleon as well as overall carapace size. The Dakoticancer Assemblage displays a variety of intersex conditions, including gonopores (vulvae) on the coxa of the fourth pereiopod and female spermatheca associated with male sternal morphology. Gonopores on the coxae of the fourth pereiopods have been reported for shrimps, clawed lobsters, and palinurid lobsters, but not for brachyurans. Understanding the occurrence of intersex specimens within an extinct species of an extinct section is extremely difficult, as there seem to be no modern analogs concerning gonopores on the fourth pereiopod in Brachyura. The low percentage of affected individuals, about 1%, suggests developmental or genetic conditions were most likely responsible for the intersex individuals. The absence of such individuals in another large collection of a species of the same genus, of more or less the same geologic age, suggests that the factors leading to intersexuality in the Dakoticancer overanus population were endemic to that population. [ABSTRACT FROM AUTHOR]

A single concretion derived from the Miocene Greta Siltstone in North Canterbury, South Island, New Zealand, contains an adult and a juvenile individual of Trichopeltarion greggi Dell, 1969. The association of an adult female and a juvenile brachyuran of the same species has not been documented previously in the fossil record. Condition of the chalky and thin endocuticle of the adult specimen suggests death and burial during the late premolt condition. Large egg size in extant Trichopeltarion spp. coupled with association of juveniles and adults in both extant and extinct species suggests that members of the genus may exhibit maternal care of juveniles. [ABSTRACT FROM AUTHOR]

Two well preserved specimens of nephropid lobster from the Late Cretaceous (late Campanian) Point Loma Formation in San Diego County, California, form the basis of description of a new species of Hoploparia. The occurrence represents the southernmost fossil record of macrurans along the Pacific coast of North America and it is only the third fossil lobster from California. [ABSTRACT FROM AUTHOR]

A collection of decapod fossils from the Miocene St. Marys Formation, Little Cove Point Member (Maryland, USA), yielded six species belonging to three genera of brachyuran crabs, Necronectes A. Milne-Edwards, 1881 , Callinectes Stimpson, 1860 , and Cancer Linnaeus, 1758. Cancer included four species, Cancer irroratus Say, 1817 ; C. borealis Stimpson, 1859 ; and two new species, C. nancei and C. zahrae. Necronectes is represented by N. drydeni Rathbun, 1935 ,. Callinectes was also represented by a single species, C. sapidus Rathbun, 1896. Most of the fossils were small relative to normal adult size, suggesting that the environment served as a nursery to developing individuals. The paleoecology of Chesapeake Bay was similar to the present-day ecology based on study of recent faunas, lithology, and paleoecology. The paleoenvironment was a shallow embayment within the temperate climate zone. [ABSTRACT FROM AUTHOR]

The description of a new species of an erymid lobster, Stenodactylina beardi , from the Upper Cretaceous Haslam Formation of the Nanaimo Group on Vancouver Island, British Columbia, Canada, brings to fifteen the number of Erymidae in North America. The species are arrayed within five genera based upon configuration of carapace groove morphology, resulting in two new combinations, Stenodactylina bordenensis (Copeland, 1960) and S. foersteri (Feldmann, 1979). The new species exhibits for the first time a male pleopod and accessory structures within Erymoidea. We also provide a list of the North American species of Erymoidea. [ABSTRACT FROM AUTHOR]

Discovery of a single specimen of a nearly complete cephalothorax and pleon of a new arthropod from the Late Devonian (Famennian) Chagrin Shale Member of the Ohio Shale Formation in Lake County, northeastern Ohio, USA documents the oldest known representative of the Axiidea. The specimen documents a new genus and species, Devonoaxius garlandi , and extends the range of the infraorder from the Jurassic into the Late Devonian. This range extension was predicted by a recent phylogenetic analysis. The addition of this axiid brings to four the number of arthropod genera in the Chagrin Shale Member, two of which represent the oldest members of their lineage. [ABSTRACT FROM AUTHOR]

Investigation of decapod crustaceans from Paleogene sediments of Mississippi has yielded one new Eocene brachyuran species, Matutites periosus n. sp. and six new Oligocene brachyuran species, Lophoranina lincki n. sp. Notopus adinae n. sp. Calappilia granulosa n. sp. C. perreaulti n. sp. C. gableorum n. sp. and Acanthocarpus osborni n. sp. Other occurrences include previously described caridean shrimp, axiids, pagurids, and raninids. Mesostylus, a callianassid, is described for the first time from Danian deposits, all other occurrences being Late Cretaceous. The Oligocene decapod fauna from Gulf Coastal North America, including localities in Alabama and Mississippi, is most like that of Pacific Coastal Baja California and most different from Pacific coastal localities from Oregon northward. [ABSTRACT FROM AUTHOR]

Palaeopalaemon newberryi Whitfield, 1880 is redescribed based upon a large collection of specimens including those collected in the nearly 40 years since P. newberryi was last evaluated. Previously undescribed aspects of its morphology include a large, pectinate maxilliped; the dactylus of pereiopod I; a triangular sternal field; well-preserved antennae, including an endopod with an antennulate flagellum; and a broad, roughly triangular scaphocerite. Phylogenetic analysis supports the position of P. newberryi as a lobster and suggests that Palaeopalaemonoidea is the sister taxon of Polychelida. Palaeopalaemon newberryi is distinct from Angustidontus, and pectinate claws shared by the two taxa may be a convergent morphology and not phylogenetically informative. Palaeopalaemon newberryi probably exhibited a benthic habit. [ABSTRACT FROM AUTHOR]

Two new families of Galatheoidea from the Mesozoic are described. Paragalatheidae encompasses members of Paragalathea and Mesogalathea, as well as two new genera: Discutiolira and Lemacola. The genus Paragalathea is herein restricted to its original definition. New species within the Paragalatheidae established in this paper are: Paragalathea arcella, P. crenarvina, P. ternata, P. vultuosona, Lemacola jenniferae, L. rossi, L. salia, Mesogalathea macra, M. pyxis, and M. retusa. The new family Catillogalatheidae is described to encompass species from the Late Jurassic and Cretaceous. New genera established within Catillogalatheidae include: Catillogalathea, Tuberosagalathea, Serraphylctaena, and Vasconilia. New species established within Catillogalatheidae are: Catillogalathea falcula, Catillogalathea patruliusi, Catillogalathea purcarenensis, Galatheites aiola, G. diasema, G. obtecta, Hispanigalathea tithonia, Tuberosagalathea antefixa, T. tornatilis, and Vasconilia xystosa. The genus Galatheites is redescribed. Some observations and remarks are made on the preservation of cuticle and ornamentation on galatheoid dorsal carapaces. [ABSTRACT FROM AUTHOR]

Patterns of diversity and faunal turnover of major groups of decapod crustaceans throughout the Phanerozoic are analyzed based upon data from all known fossil species reported to date. Age, range, and habitat preference data were compiled for 3637 species arrayed in 1035 genera and 173 families. Grouped at the infraordinal level, Anomura, Gebiidea, and Axiidea consistently occupied specific, preferred environments throughout their geologic history. Achelata are known from a variety of siliciclastic environments until the Holocene when they are found in coral and other carbonate environments. Habitat preferences of dendrobranch and pleocyemate shrimp, with a low preservation potential, are difficult to evaluate because they are found almost exclusively in low energy siliciclastics and lithographic limestones, whose mode of origin is not clear. Clawed lobsters, the so-called podotreme or primitive crabs, and heterotreme crabs have historically occupied a wide range of habitats. However, the temporal pattern of diversity of these groups is one of faunal turnover on a scale of tens of millions of years. Clawed lobsters were the first of these groups to be most diverse, followed in the Late Jurassic and Cretaceous by the podotreme or primitive crabs. Heterotreme crabs appeared in the Early Cretaceous and dominate numerically in the Cenozoic. These patterns of habitat preference of broad groups of decapods suggest that the limits of distribution are controlled by the Bauplan of each group rather than by extrinsic factors. [ABSTRACT FROM AUTHOR]

Analyses of diversity patterns at the infraorder, superfamily and family level demonstrate that the lobsters as a group were significantly more diverse in the Mesozoic, especially the Triassic and Jurassic, than in the Cenozoic and Holocene. Peaks in numbers of genera occurred in the Late Jurassic (Oxfordian and Tithonian), Upper Cretaceous (Cenomanian and Campanian), and Holocene. Smaller peaks occurred in the Lower Triassic (Anisian) and Eocene (Lutetian). Analysis of substrate preferences for various families, based upon rock type enclosing the fossils, suggests that Nephropoidea and Erymidae were quite variable in substrate preference. When examined by energy-level preferences, most lobster groups exhibit preferences; some preferences changed through time. A long-standing preference for low energy substrates appears to support the long held hypotheses that Nephropidae moved into deeper water either because of the end-Cretaceous events, or due to competition with brachyurans. Inhabitation of many types of substrates seems to predict survival of mass-extinction events in lobsters as does a shift in substrate preference through time. Lobsters can be arranged into three evolutionary faunas, Triassic, Jurassic, and Modem, that are distinct and exhibit discrete body plan and faunal turnover patterns. Several biases in the dataset have been identified. These include a strong bias toward European, Mesozoic occurrences at the expense of other locations and times; an environmental bias toward epicontinental versus oceanic or active margin occurrences; and monographic biases. [ABSTRACT FROM AUTHOR]

Copyright of Crustaceana is the property of Brill Academic Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Two new genera, Anisaeger and Distaeger, and three new species, Anisaeger brevirostrus, A. spiniferus, and Distaeger prodigiosus, extend the range of the Aegeridae (Dendrobranchiata, Penaeoidea) into the Middle Triassic (Anisian) of China. Seven decapod crustacean species are now known from the Luoping biota of southern China. Morphological features of shrimp that are present but rarely mentioned in the neontological literature are recognized as potentially useful in classifying fossil material, including a diaeresis on the exopod of the uropods and multiarticulate flagellae on pleopods. Unusual taphonomic features of the shrimp include fractured cuticle, preservation in lateral, dorsal, and ventral position, and twisted cephalothoraxes. [ABSTRACT FROM AUTHOR]

Phylogenetic analysis of most genera within fossil and extant Raninoida (Brachyura) based on 72 adult morphological characters yielded a new superfamily and family level classification for the section. The section was most diverse at the family level during the Late Cretaceous but remains diverse at the genus and species level in the Holocene. New subfamilies include Bicornisranininae, Macroacaeninae, and Rogueinae within Lyreididae. New genera include Colombicarcinus, Alessandranina, Claudioranina, Giulianolyreidus and Italianira, and one new species, Colombicarcinus laevis, is described. New combinations include Alessandranina ornata (Wright and Collins, 1972), Claudioranina oblonga (Beschin, Busulini, de Angeli, and Tessier, 1988), Heus manningi (Bishop and Williams, 2000), Italianira punctulata (Beschin, Busulini, de Angeli, and Tessier, 1988), Giulianolyreidus bidentatus (Rathbun, 1935a), G. johnsoni (Rathbun, 1935a), Lyreidus teodorii (van Bakel et al., 2012), Macroacaena tridens (Roberts, 1962), M. teshimai (Fujiyama and Takeda, 1980), M. yanini (Ilyin and Alekseev, 1998) and Quasilaeviranina eocenica (Rathbun, 1935a). [ABSTRACT FROM AUTHOR]

A phylogenetic analysis including representatives from 44 extinct and 27 extant families of lobsters (Polychelida, Achelata, Glypheidea, and Astacidea), resulted in the recognition of one new superfamily, Glaessnericarioidea, and three new families, Glaessnericariidae, Neoglypheidae, and Litogastroidae. Two families, Protastacidae and Stenochiridae, are elevated to superfamily status. A new classification of Glypheidea is proposed and currently known genera are rearranged based upon the phylogenetic analysis. Palaeopalaemonida is given a separate infraordinal status. Diagnoses for all infraorders, superfamilies, and families are provided. [ABSTRACT FROM AUTHOR]

Goniodromitidae is an extinct family of primarily Jurassic and Cretaceous crabs that are found mainly in Europe. Herein, we report upon a diversity hotspot for goniodromitids from the Koskobilo quarry in northern Spain exposing mid-Cretaceous (AlbiardCenomanian) coral reef limestones. Five species of goniodromitid are described and discussed: Distefania incerta, D. renefraaijei n. sp., Eodromites grandis, Goniodromites laevis, and Navarradromites pedroartali n. gen., n. sp. Furthermore, Distefania centrosa is herein synonymized with D. incerta. Eodromites grandis was previously known only from the Late Jurassic, resulting in a time gap of 45 Myr. Other species of decapod with long time ranges are known. Additionally, the Spanish representatives of Eodromites grandis are the only Cretaceous specimens known from this genus. Species of the genera Distefania, Eodromites, and Goniodromites were predominantly found in coral/sponge limestones from the Jurassic and Cretaceous of Europe and were important for the survival of the family into the Cretaceous and indirectly into the Paleocene. [ABSTRACT FROM AUTHOR]

Abstract: Galatheoids, squat lobsters, have recently received much systematic attention. We describe, discuss, and illustrate ten species of galatheoids found in the mid-Cretaceous (Albian/Cenomanian) Aldoirar patch reef in northern Spain. All are found in the abandoned Koskobilo quarry. The new taxa include two new genera, Hispanigalathea gen. nov. and Nykteripteryx gen. nov., and four new species: Hispanigalathea pseudolaevis sp. nov., H. tuberosa sp. nov., Nykteripteryx rostrata sp. nov., and Eomunidopsis aldoirarensis sp. nov. We redescribe E. navarrensis, E. orobensis, Paragalathea ruizi, P. straeleni, and P. multisquamata. Finally, an indeterminate galatheoid is also recognized. To date, this is by far the richest galatheoid fauna known in terms of the number of species and genera from the Cretaceous, both on the locality and formation level. This diversity is probably related to the reef facies in which the galatheoids were discovered. [Copyright &y& Elsevier]

A large collection of macrurous decapod crustaceans is recorded from the middle-late Anisian (Middle Triassic) Guanling Formation in Yunnan Province, China. A remarkable assemblage of over 20,000 vertebrate, invertebrate, and plant fossils collectively referred to as the Luoping Biota has been collected from quarries in the vicinity of the city of Luoping. Among these, arthropods including the decapods are the most common element although articulated fish and reptiles are also common. The decapods represent new taxa, including Koryncheiros luopingensis n. gen. n. sp. within Clytiopsidae, a newly elevated family within Erymoidea; Tridactylastacus sinensis n. gen. n. sp. within Glypheidae; and Yunnanopalinura schrami n. gen. n. sp. within Palinuridae. A single specimen has been referred to Palinuridae sp. Koryncheiros luopingensis exhibits a unique cheliped architecture and the second through fourth chelipeds are subchelate, an extremely rare configuration. Tridactylastacus sinensis also exhibits subchelate closures of pereiopods 2-4, but it bears a distinctive subchelate first pereiopod with an intercalated spine between the fingers on the distal margin of the propodus. Yunnanopalinura schrami represents the oldest occurrence of Palinuridae and Achelata. Collectively, these expand our knowledge of Chinese decapods significantly in that only six species of fossil decapods have been described previously from the country. [ABSTRACT FROM AUTHOR]

Small concretions and specimens embedded in the matrix have yielded a new Pliocene crustacean fauna from the Kowai Formation near Makikihi, South Canterbury, New Zealand. The fauna is relatively robust, with five identifiable taxa. Three new species are named herein, including the isopod Cirolana makikihi and the decapods Upogebia kowai and Austrohelice manneringi. one new genus and species of decapod, Kowaicarcinus maxwellae, is also named. The fauna documents the second occurrences of fossil isopod and upogebiid from New Zealand. The fauna is indicative of a nearshore setting with some mixing with taxa from shallow, offshore, normal marine settings. [ABSTRACT FROM AUTHOR]

A single carapace and its counterpart of an erymoid lobster collected from the Middle Jurassic Smithers Formation in British Columbia, permits description of a new species, Eryma walkerae. The specimen represents only the fourth species of Eryma described from North America and documents a north polar route of dispersal for erymids into North America. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Concretions collected from Motunau and Glenafric Beaches, North Canterbury, New Zealand, have yielded a new genus and species of crab, Tongapapaka motunauensis of the xanthoid family Pseudoziidae and several specimens of the cancrid crab Metacarcinus novaezelandiae (Jacquinot in Jacquinot and Lucas), confirming its range from Miocene to Holocene. These beaches have yielded numerous specimens of decapod crustaceans, the lobsters and crabs, over the decades, and the composition of the decapod fauna suggests an offshore setting for the Greta Siltstone and Mt Brown Formation exposed at Motunau and Glenafric Beaches, respectively. [ABSTRACT FROM AUTHOR]

Paleobiogeographic patterns of decapod crustaceans from the Southern Hemisphere, based upon 441 species-level records arrayed in 154 genera, document global patterns of distribution that can be compared to those previously published on decapods from the North Pacific and Central American regions. All known records of decapods from the Southern Hemisphere spanning the Early Triassic to Pleistocene have been compiled, nearly all have been personally verified, and patterns of origin and distribution have been interpreted. Interchange between hemispheres, including amphitropical and bipolar distributions, are recognized from Jurassic to post— Miocene time. The high southern latitudes was a site of origin of several generic-level taxa during the Jurassic through Eocene and many of these taxa have been identified in subsequent times in lower latitude regions in shallow- and deepwater environments in both hemispheres. The isolation of Antarctica due to ocean currents significantly diminished the role of the high southern latitudes as an area of origin for decapods. The Tethys was an important dispersal pathway for decapods during the Cretaceous through early Miocene. Endemism was high during the Eocene, similar to the North Pacific and Central America. The magnitude of the Cretaceous/Paleogene extinction event on the Southern Hemisphere decapod fauna was not profound; most Cretaceous extinctions seem to have occurred well before the end of the Cretaceous, and 85% of the Cretaceous families are known from the Paleogene in the Southern Hemisphere taxa. [ABSTRACT FROM AUTHOR]

This paper offers a preliminary description of a plesiosaur (Reptilia: Sauropterygia) from the Lower Toarcian Posidonienschiefer near the village of Holzmaden in Baden-Württemberg, Germany, and discusses its phylogenetic relevance. This new taxon, Plesiopterys wildi new genus and species, is remarkable in its retention of several plesiomorphic features. A phylogenetic analysis places Plesiopterys as the sister group of the Plesiosauroidea, and as such the taxon is the most basal taxon yet known on the branch leading to this major clade. Plesiopterys possesses a high count of cervical vertebrae and a relatively small head, yet the limbs and limb girdles are plesiomorphic in proportion. The skull displays a mosaic of features, reminiscent of both Thalassiodracon and the rhomaleosaurids in some characters, yet similar to Plesiosaurus in others. The basicranium is plesiomorphic and resembles that of nothosaur-grade sauropterygians in several respects. A faunal comparison between Holzmaden and the Lower Toarcian deposits on the Yorkshire coast of England concludes that the Holzmaden fauna is more plesiomorphic than the roughly coeval Yorkshire fauna in two of three plesiosaur subclades. [ABSTRACT FROM AUTHOR]

Epibionts on both living and fossil decapod crustaceans may serve as valuable proxies for paleoecological factors such as behavior and environment. Prevalence of epibionts, as observed primarily on the carapaces of fossil brachyurous decapod crustaceans, appears to be less than observed on living crabs, based upon observations in the literature, and from the study of a limited preserved biological and fossil collection. Among these factors, the three most important are that many extant epibionts do not possess skeletal structures and, therefore, are unlikely to be preserved; the epicuticle upon which epibionts attach to living brachyurans is lightly calcified and tends to be lost readily as a result of taphonomic processes; and the most common mode of preservation of fossil brachyurans is in concretions which tend to break open and leave a layer of cuticle on the counterpart, thus obscuring the potential surface of attachment of epibionts. Other factors such as the life habits of the crab, whether burrowing, burying, or remaining above the substrate; lifestyle, whether benthic or pelagic; and duration of the intermolt phase of the organism also play important roles in potential prevalence of epibionts. Careful preparation of part and counterpart remains of brachyurans as well as reference to the occurrence of epibionts in systematic studies will enhance knowledge of the host and epibiont. [ABSTRACT FROM AUTHOR]

Reevaluation of 21 specimens of Permian crustaceans from near Palermo, Italy, referred to Palaeopemphix Gemmellaro, 1890, has resulted in transfer of the genus from the decapod Crustacea to a new suborder, the Palaeopemphida, and a new superfamily, Palaeopemphidae, of the archaeostracan Phyllocarida. [ABSTRACT FROM AUTHOR]

A new trace fossil, Foersterichnus rossensis igen. nov. and isp. nov., is described from the Coniacian Hidden Lake Formation, James Ross Island, Antarctica. The trace fossil is a trackway comprising straight, or slightly curving, paired rows of elongate to tear-shaped impressions, parallel or slightly inclined to the long axis of the trackway. Foersterichnus is interpreted to be the trackway of a brachyuran decapod crustacean. It occurs in transgressive shallow marine deposits formed above the storm wave base in a shelf setting. Preservation of the trackway may have been linked to a rapid deoxygenation event during drowning that led to cessation of bioturbation allowing preservation of mixed layer trackways. [ABSTRACT FROM AUTHOR]

Research on fossil decapod crustaceans has accelerated since the publication of the Treatise on Invertebrate Paleontology dealing with the group. Increase in the number of paleontologists studying the Decapoda, exploration of previously poorly known areas, and major advances in neontological research has made it possible to transform fossil decapods from the category of interesting and beautiful fossils to that of useful subjects for research in paleoecology and paleobiogeography. Classification of fossil decapods has become more refined as new taxa have been recognized in the fossil record and as neontological approaches to classification, including larval anatomy, comparative spermatology, morphology of novel structures, and molecular analysis, are considered in conjunction with fossil evidence. This combination of approaches can now be used to develop testable hypotheses regarding phylogeny of the group. Detailed observational data on living and fossil biotic associations has been coupled with experimental studies to enhance our understanding of organic interactions as well as to understand the biasing factors of taphonomy that affect the fossil record of organisms with organic exoskeletons. Broad studies of distribution of decapods in time and space are now possible, owing to the increase in number of fossil sites studied and taxa described. We can define patterns of biogeographic distribution that can be tested against patterns derived from the study of more commonly preserved organisms, such as the mollusks. As this research continues, it is anticipated that studies of paleobiogeography and paleoecology will increasingly rely on data from the fossil record of the decapod Crustacea. [ABSTRACT FROM AUTHOR]

Examination of two well-preserved Cenomanian (Late Cretaceous) specimens of a glypheid lobster from Northern Territory, Australia, permits description of a new species, Glyphea foresti. The epistome of the new species and of Glyphea alexandri Taylor, 1979, and G. regleyana (Desmarest, 1822) is not fused to the cephalothorax. Southern hemisphere representatives of the genus Glyphea exhibit similarities in development of the carapace grooves suggesting that they are closely allied and that they may have been the rootstock of the living, tropical western Pacific Neoglyphea inopinata Forest & de Saint Laurent, 1975. The rounded margins of the abdominal pleura suggest that the paratype specimen is a female, based upon comparison with that region on Neoglyphea inopinata. Sexual dimorphism was previously recognized in Glyphea regleyana by Etallon (1858). [ABSTRACT FROM AUTHOR]

Reports on a study examining the feminization of the `Tumidocarcinus giganteus Glaessner,' adult male xanthid crabs in Miocene, New Zealand. Relationship between the parasitic barnacles and the decapod crustaceans; Methodology used to conduct the study; Results of the study.

The article reports on the new family, genus, and species of lobster from the Gadvan formation of Iran. There are scarce records of fossil decapod crustaceans from Iran. Microcoprolites with an internal structure characteristics of decapods are known from the Jurassic of Iran which is the basis for description of a new family, genus, and species of palinuroid lobster.

An incomplete arthropod fossil, Tricarina gadvanensis Feldmann et al., 2007, from the Lower Cretaceous (Barremian–Aptian) of Iran, originally interpreted as a lobster (Malacostraca, Eucarida, Decapoda), is reinterpreted herein as a representative of a seroloid isopod crustacean (Malacostraca, Peracarida, Isopoda). The body orientation of the fossil is reversed, and the alleged cephalothoracic shield is reinterpreted as being the pleotelson. Tricarina gadvanensis, with its unique configuration of pleonite fusion (pleonites 1–4 are free, whereas pleonite 5, with still visible epimera, is fused with the pleotelson), is suggested to represent a close relative of Serolidae. The preservation of T. gadvanensis in deepwater shales speaks for conservativeness in environmental preferences of seroloid isopods for at least 125 million years. [ABSTRACT FROM AUTHOR]

The ecological and physiological significance of body size is well recognized. However, key macroevolutionary questions regarding the dependency of body size trends on the taxonomic scale of analysis and the role of environment in controlling long-term evolution of body size are largely unknown. Here, we evaluate these issues for decapod crustaceans, a group that diversified in the Mesozoic. A compilation of body size data for 792 brachyuran crab and lobster species reveals that their maximum, mean and median body size increased, but no increase in minimum size was observed. This increase is not expressed within lineages, but is rather a product of the appearance and/or diversification of new clades of larger, primarily burrowing to shelter-seeking decapods. This argues against directional selective pressures within lineages. Rather, the trend is a macroevolutionary consequence of species sorting: preferential origination of new decapod clades with intrinsically larger body sizes. Furthermore, body size evolution appears to have been habitat-controlled. In the Cretaceous, reef-associated crabs became markedly smaller than those in other habitats, a pattern that persists today. The long-term increase in body size of crabs and lobsters, coupled with their increased diversity and abundance, suggests that their ecological impact may have increased over evolutionary time. [ABSTRACT FROM AUTHOR]