Articles de revues : « Echinoida Echinoida Echinoida »

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M�rkel, Konrad, Ursula R�ser, Ute Mackenstedt et Melanie Klostermann. « Ultrastructural investigation of matrix-mediated biomineralization in echinoids (Echinodermata, Echinoida) ». Zoomorphology 106, n^o 4 (octobre 1986) : 232–43. http://dx.doi.org/10.1007/bf00312044.

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Shin, Sook. « A New Record of Sea Urchin (Echinoidea : Echinoida) from Jejudo Island, Korea ». Animal Systematics, Evolution and Diversity 24, n^o 3 (30 novembre 2008) : 323–26. http://dx.doi.org/10.5635/kjsz.2008.24.3.323.

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Philippi, U., et Werner Nachtigall. « Functional morphology of regular echinoid tests (Echinodermata, Echinoida) : a finite element study ». Zoomorphology 116, n^o 1 (20 mars 1996) : 35–50. http://dx.doi.org/10.1007/s004350050007.

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Philippi, Ute, et Werner Nachtigall. « Functional morphology of regular echinoid tests (Echinodermata, Echinoida) : a finite element study ». Zoomorphology 116, n^o 1 (mars 1996) : 35–50. http://dx.doi.org/10.1007/bf02526927.

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Thompson, Jeffrey R., Shi-xue Hu, Qi-Yue Zhang, Elizabeth Petsios, Laura J. Cotton, Jin-Yuan Huang, Chang-yong Zhou, Wen Wen et David J. Bottjer. « A new stem group echinoid from the Triassic of China leads to a revised macroevolutionary history of echinoids during the end-Permian mass extinction ». Royal Society Open Science 5, n^o 1 (janvier 2018) : 171548. http://dx.doi.org/10.1098/rsos.171548.

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The Permian–Triassic bottleneck has long been thought to have drastically altered the course of echinoid evolution, with the extinction of the entire echinoid stem group having taken place during the end-Permian mass extinction. The Early Triassic fossil record of echinoids is, however, sparse, and new fossils are paving the way for a revised interpretation of the evolutionary history of echinoids during the Permian–Triassic crisis and Early Mesozoic. A new species of echinoid, Yunnanechinus luopingensis n. sp. recovered from the Middle Triassic (Anisian) Luoping Biota fossil Lagerstätte of South China, displays morphologies that are not characteristic of the echinoid crown group. We have used phylogenetic analyses to further demonstrate that Yunnanechinus is not a member of the echinoid crown group. Thus a clade of stem group echinoids survived into the Middle Triassic, enduring the global crisis that characterized the end-Permian and Early Triassic. Therefore, stem group echinoids did not go extinct during the Palaeozoic, as previously thought, and appear to have coexisted with the echinoid crown group for at least 23 million years. Stem group echinoids thus exhibited the Lazarus effect during the latest Permian and Early Triassic, while crown group echinoids did not.

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Yamazaki, Atsuko, Yousuke Furuzawa et Masaaki Yamaguchi. « Conserved early expression patterns of micromere specification genes in two echinoid species belonging to the orders clypeasteroida and echinoida ». Developmental Dynamics 239, n^o 12 (2 novembre 2010) : 3391–403. http://dx.doi.org/10.1002/dvdy.22476.

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Jung, Gila, Hee-Jung Choi, Sejin Pae et Youn-Ho Lee. « Complete mitochondrial genome of sea urchin:Mesocentrotus nudus(Strongylocentrotidae, Echinoida) ». Mitochondrial DNA 24, n^o 5 (11 février 2013) : 466–68. http://dx.doi.org/10.3109/19401736.2013.766181.

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ARACHCHIGE, GAYASHAN M., SEVVANDI JAYAKODY, RICH MOOI et ANDREAS KROH. « A review of previous studies on the Sri Lankan echinoid fauna, with an updated species list ». Zootaxa 4231, n^o 2 (9 février 2017) : 151. http://dx.doi.org/10.11646/zootaxa.4231.2.1.

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A comprehensive review and analysis of the literature on echinoids from Sri Lankan waters were conducted to compile an annotated list that integrates the existing published data with original data from recent research. According to the published literature, 115 echinoid species and one subspecies have been reported from Sri Lanka to date. However, the current study revealed that only 66 echinoid species and one subspecies belonging to 20 families can be verified to occur in Sri Lankan waters. According to the present analysis, 49 species were excluded from the list due to uncertain records (16) or synonymy (33) with other taxa known from the region. Of the 66 species and one subspecies occurring in Sri Lankan waters, 11 were first described from type material collected from this region. Six of the type specimens are “regular” echinoids and five are Irregularia. Out of these 11, Araeosoma coriaceum indicum has been recorded only from and appears to be endemic to Sri Lankan waters. However, 34 species of Sri Lankan echinoids have not been recorded in the last 90 years. Echinoid species recorded from Sri Lankan waters represent 6.7% of the currently accepted species of extant echinoids and include representatives of 28% of the extant echinoid families. Forty-five percent (45%) of echinoids recorded from the Indian coast (113 species and subspecies) are present in Sri Lankan waters. The current study highlights the need for systematic revision of echinoid records in Sri Lanka through field surveys and reconciliation of discrepancies in the existing literature. Offshore sampling is also needed due to lack of recent information on local deep-sea echinoids.

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Mancosu, Andrea, et James H. Nebelsick. « Paleoecology of sublittoral Miocene echinoids from Sardinia : A case study for substrate controls of faunal distributions ». Journal of Paleontology 93, n^o 04 (11 avril 2019) : 764–84. http://dx.doi.org/10.1017/jpa.2019.4.

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AbstractA rich echinoid fauna within the middle Miocene carbonate sedimentary succession cropping out along the coast between Santa Caterina di Pittinuri and S'Archittu (central-western Sardinia) allows the comparison of faunal gradients and preservation potentials from both hard and soft substrata. Three echinoid assemblages are recognized. Faunal composition, as well as taphonomic and sedimentological features and functional morphological interpretation of the echinoid test indicate an outer sublittoral setting. Assemblage 1 represents a highly structured environment within the photic zone, with mobile substrata occupied by infaunal irregular echinoids, mainly spatangoids, and localized hard substrata, provided by rhodolith beds, with epibenthic regular echinoids represented by the co-occurrence of the diadematidDiademaGray, 1825 and the toxopneustidsTripneustesL. Agassiz, 1841 andSchizechinusPomel, 1869. Assemblage 2 shows a higher diversity of irregular echinoids, dominated by the clypeasteroidsEchinocyamusvan Phelsum, 1774 andClypeasterLamarck, 1801 and different spatangoids, with the minute trigonocidaridGenocidarisA. Agassiz, 1869 among regular echinoids. This assemblage points to a soft-bottom environment with moderate water-energy conditions, periodically affected by storms. A low-diversity echinoid fauna in Assemblage 3, dominated by the spatangoidsBrissopsisL. Agassiz, 1840 andOvaGray, 1825, documents a deeper, soft-bottom environment, possibly below storm-wave base. These results indicate that the diversity of echinoid faunas originating in sublittoral environments is related to: (1) the presence of both soft and hard substrata, (2) differential preservation potentials of the various echinoid taxa, (3) intense bioturbation, and (4) sediment deposition by sporadic storm events.

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Carter, Burchard D. « Inferring substrate preferences from test morphology in echinoids, and interpreting spatial and temporal patterns of diversity ». Paleontological Society Papers 3 (octobre 1997) : 121–45. http://dx.doi.org/10.1017/s1089332600000231.

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Preservational style of fossil echinoid tests allows assessment of the likelihood of post-mortem transport out of the preferred sediment type of the living echinoid. Sedimentologic study of the matrix of untransported specimens allows a check on functional morphologic inferences of the species' preferred sediment types. Functional morphologic analysis allows inference of a species preferred sediment type because the petals, fasciolaes, tubercles, ambulacral pores, ambulacral shape, and test profile control the echinoid's ability to burrow, and the grain size of sediment into which it is capable of doing so. Past studies have achieved better than 90% accuracy in predicting the grain size of thin sections of rocks containing echinoids, simply by interpretation of their functional morphology. Most mistaken predictions are attributable to species living in sediments that are less difficult to burrow in (sands) than those to which they are adapted (muds). Other species may live in sediments in which they are not well adapted by assuming an epifaunal mode of life.Relative proportions of species in an echinoid fauna preferring various sediment grain sizes, plotted for each of a number of localities, has proven useful in inferring generalized facies patterns within regions.Plots of temporal changes in echinoid species diversity through time correspond well to changes in proportions of species inferred to have preferred various substrate conditions, suggesting an environmental and taphonomic component to simple diversity curves.

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Nebelsick, James H. « Actuopaleontological investigations of shallow water Red Sea echinoids ». Paleontological Society Special Publications 6 (1992) : 220. http://dx.doi.org/10.1017/s2475262200007802.

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The regular and irregular echinoid fauna of the Northern Bay of Safaga (Red Sea, Egypt) has been investigated within the framework of an actuopaleontological study of the flora, fauna, sediments and facies. The distribution of echinoids has been compared to grain size parameters as well as to the distribution of other organisms.The study area (ca. 10 × 7 km) was investigated using SCUBA-diving techniques along 55 transects with a total length of 126 km. Echinoid presence was quantified using weights of fragments (2 mm) originating from 67 standardized bulk samples distributed throughout the Bay. The complex morphology of the echinoid test and the spines allow the identification of fragmented material upon comparison to complete specimens. The resulting data was analyzed using correlation techniques as well as Q and R-mode multivariate statistical analysis. This method counters the difficulties originating from the cryptic habitats and patchy distributions.The results of the analysis show that echinoid distribution can be analyzed for both regular and irregular wchinoid taxa despite taphonomic bias and restrictions imposed by the analytic method. Time averaging in fact counters the difficulties arising from the patchy distributions of echinoids. There is a close correlation of echinoid distribution to sedimentary and bottom facies as well as to grain size parameters and other environmental factors. The distribution of irregular echinoids is highly differentiated with coarse coastal sand dominated by Clypeaster sp., Echinodiscus auritus, Fibularia ovulum, and Lovenia elongata; muddy sands by Laganum depressum, Clypeaster sp. and Echinocyamus crispus; and muds by members of the Schizasteridae. Regular echinoids, mostly Eucidaris metularia, Echinometra mathaei, Tripneustes gratilla, Heterocentrotus mammillatus and Diadema setosum, dominate the sediments found within, or near reefs, coral carpets and patch reefs.The methodology used in this actuopaleontological investigation should be useful in recognizing the distribution patterns of ancient echinoid faunas, especially in light of the significance of regular echinoids in the bioerosion of reefs and irregular echinoids in the bioturbation of sediments.

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Thompson, Jeffrey R., Renato Posenato, David J. Bottjer et Elizabeth Petsios. « Echinoids from the Tesero Member (Werfen Formation) of the Dolomites (Italy) : implications for extinction and survival of echinoids in the aftermath of the end-Permian mass extinction ». PeerJ 7 (30 août 2019) : e7361. http://dx.doi.org/10.7717/peerj.7361.

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The end-Permian mass extinction (∼252 Ma) was responsible for high rates of extinction and evolutionary bottlenecks in a number of animal groups. Echinoids, or sea urchins, were no exception, and the Permian to Triassic represents one of the most significant intervals of time in their macroevolutionary history. The extinction event was responsible for significant turnover, with the Permian–Triassic representing the transition from stem group echinoid-dominated faunas in the Palaeozoic to Mesozoic faunas dominated by crown group echinoids. This turnover is well-known, however, the environmental and taxonomic distribution of echinoids during the latest Permian and Early Triassic is not. Here we report on an echinoid fauna from the Tesero Member, Werfen Formation (latest Permian to Early Triassic) of the Dolomites (northern Italy). The fauna is largely known from disarticulated ossicles, but consists of both stem group taxa, and a new species of crown group echinoid,Eotiaris teseroensisn. sp. That these stem group echinoids were present in the Tesero Member indicates that stem group echinoids did not go extinct in the Dolomites coincident with the onset of extinction, further supporting other recent work indicating that stem group echinoids survived the end-Permian extinction. Furthermore, the presence ofEotiarisacross a number of differing palaeoenvironments in the Early Triassic may have had implications for the survival of cidaroid echinoids during the extinction event.

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Thompson, Jeffrey R., Elizabeth Petsios et David J. Bottjer. « A diverse assemblage of Permian echinoids (Echinodermata, Echinoidea) and implications for character evolution in early crown group echinoids ». Journal of Paleontology 91, n^o 4 (18 avril 2017) : 767–80. http://dx.doi.org/10.1017/jpa.2016.158.

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AbstractThe Permian is regarded as one of the most crucial intervals during echinoid evolution because crown group echinoids are first widely known from the Permian. New faunas provide important information regarding the diversity of echinoids during this significant interval as well as the morphological characterization of the earliest crown group and latest stem group echinoids. A new fauna from the Capitanian Lamar Member of the Bell Canyon Formation in the Guadalupe Mountains of West Texas comprises at least three new taxa, includingEotiaris guadalupensisThompson n. sp. an indeterminate archaeocidarid, andPronechinus? sp. All specimens represented are silicified and known from disarticulated or semiarticulated interambulacral and ambulacral plates and spines. This assemblage is one of the most diverse echinoid assemblages known from the Permian and, as such, informs the paleoecological setting in which the earliest crown group echinoids lived. This new fauna indicates that crown group echinoids occupied the same environments as stem group echinoids of the Archaeocidaridae and Proterocidaridae. Furthermore, the echinoids described herein begin to elucidate the order of character transitions that likely took place between stem group and crown group echinoids. At least one of the morphological innovations once thought to be characteristic of early crown group echinoids, crenulate tubercles, was in fact widespread in a number of stem group taxa from the Permian as well. Crenulate tubercles are reported from two taxa, and putative cidaroid style U-shaped teeth are present in the fauna. The presence of crenulate tubercles in the archaeocidarid indicates that crenulate tubercles were present in stem group echinoids, and thus the evolution of this character likely preceded the evolution of many of the synapomorphies that define the echinoid crown group.

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Campos, Lucia S., et Rafael B. Moura. « Macrostructure and evolution of the digestive system in Echinoida (Echinodermata) ». Zoomorphology 127, n^o 3 (19 février 2008) : 135–41. http://dx.doi.org/10.1007/s00435-008-0058-4.

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GONDIM, ANNE ISABELLEY, RAFAEL BENDAYAN DE MOURA, MARTIN LINDSEY CHRISTOFFERSEN et THELMA LÚCIA PEREIRA DIAS. « Taxonomic guide and historical review of echinoids (Echinodermata : Echinoidea) from northeastern Brazil ». Zootaxa 4529, n^o 1 (10 décembre 2018) : 1. http://dx.doi.org/10.11646/zootaxa.4529.1.1.

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The class Echinoidea contains among the best-known echinoderms. The group has left the most complete fossil record of this phylum, and contains about 1000 living species, of which 51 are recorded along the Brazilian coast. Although the first record of echinoids in Brazil was made 369 years ago, the knowledge of this fauna remains quite unsatisfactory from a taxonomic and ecological point of view, particularly in the north and northeastern regions of the country. This study provides the first annotated list of echinoids from northeastern Brazil. The studied material largely belongs to collections of the Federal University of Paraíba (CIPY), Federal University of Sergipe (LABIMAR-UFS), Federal University of Bahia (MZUFBA), University of São Paulo (MZUSP), and National Museum of the Federal University of Rio de Janeiro (MNRJ). Thirty-two species from 29 genera, 18 families, and 10 orders were identified. Descriptions of species are provided. Highest diversities of Echinoidea were encountered for the states of Bahia (19 spp.), Alagoas (11 spp.), Paraíba (10 spp.), Ceará (7 spp.), Rio Grande do Norte (7 spp.), and Pernambuco (6 spp.). On the basis of the data analysed, Maranhão (2 spp.), Piauí (2 spp.), and Sergipe (3 spp.) have the lowest diversity. Sandy substrates and depths below 10 m were the least sampled areas over the continental shelf. Although the studied species are common, some taxonomic problems were encountered and discussed. We also provide ecological information and comments on status of the species from the studied region. As a result of this inventory, we were able to provide the first assessment of the echinoid fauna of northeastern Brazil.

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Märkel, Konrad, Ute Mackenstedt et Ursula Röser. « The sphaeridia of sea urchins : ultrastructure and supposed function (Echinodermata, Echinoida) ». Zoomorphology 112, n^o 1 (mars 1992) : 1–10. http://dx.doi.org/10.1007/bf01632989.

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Bureau, F., Ph Dubois, M. Ghyoot et M. Jangoux. « Skeleton resorption in echinoderms : Regression of pedicellarial stalks inSphaerechinus granularis (Echinoida) ». Zoomorphology 110, n^o 4 (juillet 1991) : 217–26. http://dx.doi.org/10.1007/bf01633006.

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Thompson, Jeffrey R., et William I. Ausich. « Facies distribution and taphonomy of echinoids from the Fort Payne Formation (late Osagean, early Viséan, Mississippian) of Kentucky ». Journal of Paleontology 90, n^o 2 (mars 2016) : 239–49. http://dx.doi.org/10.1017/jpa.2016.46.

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AbstractPaleozoic echinoids are exceptionally rare, and little is known of their paleoenvironmental distribution. The echinoid fauna of the Fort Payne Formation (Late Osagean, Early Viséan) of south-central Kentucky is documented. Four genera, ?Archaeocidaris, Lepidocidaris, ?Lepidesthes, and an unidentified lepidocentrid, were recovered and represent three different families. This fauna, and their associated paleoenvironments, give important new insights into the facies distribution of Paleozoic echinoids and the taphonomic biases that affect this distribution. Lepidocidaris is known from the green shale facies, which comprises the core of Fort Payne’s carbonate buildups. ?Archaeocidaris and the lepidocentrid are known from the wackestone buildups and crinoidal packstone buildups. ?Lepidesthes is also known from crinoidal packstone and wackestone buildups, which argues against a semi-infaunal life mode for this taxon. All relatively semiarticulated echinoids were known from autochthonous facies, whereas the only echinoids from the allochthonous facies were disarticulated hemipyramids. Furthermore, deeper-water carbonate buildups were apparently capable of supporting diverse echinoid faunas during the Viséan.

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SCHLÜTER, NILS, MORTEZA TAHERPOUR-KHALIL-ABAD, MAHMOUDREZA MAJIDIFARD, ZINAT HASSANZADEH et JAFAR TAHERI. « Two echinoid species from the early Aptian (Early Cretaceous) of the Kopet-Dagh Basin, NE Iran ». Zootaxa 4656, n^o 1 (13 août 2019) : 121–32. http://dx.doi.org/10.11646/zootaxa.4656.1.5.

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Two echinoid species from the Sarcheshmeh Formation, early Aptian, Lower Cretaceous, of the Kopet-Dagh Basin, NE Iran, are described: a phymosomatoid specimen of Tetragramma sp., and the spatangoid echinoid Miotoxaster collegnii (Sismonda, 1844). This is the first report of echinoids from the Sarcheshmeh Formation from northeastern Iran.

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Grun, Tobias B., Malte von Scheven, Manfred Bischoff et James H. Nebelsick. « Structural stress response of segmented natural shells : a numerical case study on the clypeasteroid echinoid Echinocyamus pusillus ». Journal of The Royal Society Interface 15, n^o 143 (juin 2018) : 20180164. http://dx.doi.org/10.1098/rsif.2018.0164.

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The skeleton of Echinocyamus pusillus is considered as an exceptional model organism for structural strength and skeletal integrity within the echinoids as demonstrated by the absence of supportive collagenous fibres between single plates and the high preservation potential of their skeletons. The structural principles behind this remarkably stable, multi-plated, light-weight construction remain hardly explored. In this study, high-resolution X-ray micro-computed tomography, finite-element analysis and physical crushing tests are used to examine the structural mechanisms of this echinoid's skeleton. The virtual model of E. pusillus shows that the material is heterogeneously distributed with high material accumulations in the internal buttress system and at the plate boundaries. Finite-element analysis indicates that the heterogeneous material distribution has no effect on the skeleton's strength. This numerical approach also demonstrates that the internal buttress system is of high significance for the overall skeletal stability of this flattened echinoid. Results of the finite-element analyses with respect to the buttress importance were evaluated by physical crushing tests. These uniaxial compression experiments support the results of the simulation analysis. Additionally, the crushing tests demonstrate that organic tissues do not significantly contribute to the skeletal stability. The strength of the echinoid shell, hence, predominantly relies on the structural design.

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ARACHCHIGE, GAYASHAN M., SEVVANDI JAYAKODY, RICH MOOI et ANDREAS KROH. « Taxonomy and distribution of irregular echinoids (Echinoidea : Irregularia) from Sri Lanka ». Zootaxa 4541, n^o 1 (3 janvier 2019) : 1. http://dx.doi.org/10.11646/zootaxa.4541.1.1.

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The earliest information on Sri Lankan echinoid species belonging to the Irregularia dates back to Alexander Agassiz (1872). However, the current knowledge of diversity and distribution of irregular echinoids from Sri Lanka (formerly Ceylon) remains sparse. In addition, there are no recent taxonomic studies or biodiversity surveys for irregular echinoids, and no illustrated field-guides or reference collections are available specifically for Sri Lanka. To address these gaps, left open for more than 100 years since the work of Clark (1915), this study was conducted as an island-wide systematic sampling survey. Over 200 echinoid specimens were collected from 24 localities in Sri Lankan coastal waters by snorkelling and SCUBA diving down to 33 m depth. The collected specimens were identified using existing keys and authenticated with specimens available at the Natural History Museum in Vienna, Austria. The present study records 22 irregular echinoid species belonging to 15 genera and nine families in four orders. Among the identified irregular echinoids, six species, Echinocyamus megapetalus H.L. Clark, 1914, Fibularia ovulum Lamarck, 1816, Fibulariella angulipora Mortensen, 1948, Echinodiscus cf. truncatus L. Agassiz, 1841, Peronella oblonga Mortensen, 1948 and Brissus cf. agassizii Döderlein, 1885, are new records for Sri Lanka. Four unidentified, possibly new species belonging to the genera Fibularia, Jacksonaster and Metalia are reported, but kept in open nomenclature until more material becomes available. At present, the diversity of irregular echinoids from Sri Lanka now stands at 37 species representing 11 families in four orders. A dichotomous key is presented for all Sri Lankan irregular echinoids.

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Nebelsick, James H. « Biodiversity of Shallow-Water Red Sea Echinoids : Implications For the Fossil Record ». Journal of the Marine Biological Association of the United Kingdom 76, n^o 1 (février 1996) : 185–94. http://dx.doi.org/10.1017/s0025315400029118.

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Determination of fossil echinoid diversities is an important aspect of detailed palaeon- tological studies. The comparison of recent and fossil associations can be used to elucidate the problems of determination of fossil echinoid distributions. Actuopalaeontological studies of echinoids from the Red Sea (northern Bay of Safaga, Egypt) have shown that the study of fragments within bulk sediment samples greatly increased the possibilities for determining echinoid presence and distribution. The results show the restricted distribution as well as the differential preservation potential of the various echinoids.The distribution of echinoids is primarily controlled by grain size, food availability, exposure to current activity, and predation pressure. Regular and irregular sea-urchins show the expected disjunct distributions with the former showing a more undifferentiated distribution to various hard substrates. Irregular echinoids are tightly restricted to particular types of soft substrates reflecting their adaptation to the specific grain size of the sediments. Co-occurring irregular sea-urchins show a spatial differentiation into shallow (clypeasteroids) and deeper burrowers (spatangoids). This investigation shows that important echinoid species known to occur in the Red Sea are lacking or are very rare within the study area, although a large number of different facies types are present. Patchy distributions are present for both regular and irregular sea-urchins. The determination of biodiversity is therefore seen to be largely dependent on the scale of investigation.An important implication for fossil echinoid presence are the differential effects of taphonomic agents on the various test architectures. Some species are well represented due to their common occurrences, and their comparatively robust tests or test fragments.

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FARRAR, LYNDSEY, ERIN GRAVES, ELIZABETH PETSIOS, ROGER W. PORTELL, TOBIAS B. GRUN, MICHAL KOWALEWSKI et CARRIE L. TYLER. « CHARACTERIZATION OF TRACES OF PREDATION AND PARASITISM ON FOSSIL ECHINOIDS ». PALAIOS 35, n^o 5 (18 mai 2020) : 215–27. http://dx.doi.org/10.2110/palo.2019.088.

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ABSTRACT Interactions with predators and parasites can result in traces found on Recent and fossil echinoids. However, identifying specific trace makers, particularly on fossil echinoids, remains contentious. To document the range of trace morphologies present on echinoids and improve our ability to identify and quantify biotic interactions affecting echinoids, we characterized traces found on fossil echinoids using museum collections and field sampling spanning the Jurassic to Recent worldwide. Using light microscopy, 8,564 individual echinoid specimens were examined including 130 species, and 516 traces of potential biotic interactions identified. Morphological characteristics were recorded for each trace, including the shape of the trace outline, maximum diameter and cross-section profile. Based on shared morphological characteristics, it was possible to classify all traces into eight categories: circular, subcircular, elongated, irregular, rectangular, figure-eight, notched, and linear. Cross-section characteristics provided additional insights into the identity of potential trace makers. To further evaluate the proposed biotic origins of these traces, trace diversity was examined through time and compared with anticipated ecological trends associated with the diversification of echinoids, and their predators and parasites. Trace diversity increased over time, starting in the late Eocene, coincident with the proliferation of echinoid-drilling gastropods, an indication that biotic interactions intensified through evolutionary time, as predicted by several macroevolutionary hypotheses previously tested using mollusks. The morphological descriptions provided here enhance our understanding of biotic traces on fossil echinoids, and the potential to identify temporal trends in the intensity and diversity of biotic interactions that have affected echinoids throughout their evolutionary history.

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Gaitán-Espitia, Juan Diego, et Gretchen E. Hofmann. « Mitochondrial genome architecture of the giant red sea urchinMesocentrotus franciscanus(Strongylocentrotidae, Echinoida) ». Mitochondrial DNA 27, n^o 1 (14 avril 2014) : 591–92. http://dx.doi.org/10.3109/19401736.2014.908359.

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Lee, Y. H. « Molecular Phylogenies and Divergence Times of Sea Urchin Species of Strongylocentrotidae, Echinoida ». Molecular Biology and Evolution 20, n^o 8 (25 avril 2003) : 1211–21. http://dx.doi.org/10.1093/molbev/msg125.

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Flammang, Patrick, et Michel Jangoux. « Functional morphology of coronal and peristomeal podia in Sphaerechinus granularis (Echinodermata, Echinoida) ». Zoomorphology 113, n^o 1 (mars 1993) : 47–60. http://dx.doi.org/10.1007/bf00430976.

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Cranmer, G. J. « Recent Investigations into the Distribution of Regular Echinoids in the North Sea ». Journal of the Marine Biological Association of the United Kingdom 65, n^o 2 (mai 1985) : 351–57. http://dx.doi.org/10.1017/s0025315400050475.

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A major contribution to our understanding of the distribution and taxonomy of echinoids in British waters was made by Mortensen (1927, 1928–1951). Many earlier qualitative investigations (e.g. Süssbach & Breckner, 1911; Brattström, 1941) which dealt only with limited areas, were combined in Mortensen (1928–1951) to produce an overall assessment of the North Sea echinoid fauna.In his discussion paper Ursin (1960) synthesized findings from his 20 year grab sample survey with the work of others to produce a valuable quantitative analysis of the echinoids of the central North Sea (54–5 8° N).In recent years (1977–1983) participation on demersal fish surveys in the North Sea has enabled the distribution and population structure of the macroepibenthic component of the water column to be recorded (Dyer et al. 1982, 1983; Cranmer, Fry & Dyer, 1984).Although this present study has added no new echinoid species to the fauna it has given a detailed picture of echinoid distribution in the area.

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Emlet, Richard B. « What is a juvenile sea urchin ? A comparative and phylogenetic survey of post-metamorphic juveniles ». Zygote 8, S1 (décembre 1999) : S44—S45. http://dx.doi.org/10.1017/s0967199400130217.

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Echinoid development progresses through embryonic and larval stages to metamorphosis and the adult form. Despite vast differences in embryos and larval forms, including bilaterally symmetric echinopluteus larvae, ovoid non-feeding larvae and brooded embryos, all metamorphose into juvenile sea urchins with pentaradial symmetry. The adult sea urchin body plan is initiated as the juvenile rudiment. The rudiment has been called the phylotypic stage for the class Echinoidea, a designation that implies little variation at this midpoint in development (e.g. Raff et al., 1991; Richardson, 1995; Raff, 1996). However, right at metamorphosis (upon eversion of the juvenile rudiment), variations in test symmetry, shape and number of spines, and number of skeletal plates, podia and pedicellariae are present in juveniles. This variation suggests either that there is no phylotypic stage or that such a stage occurs earlier in rudiment formation. To distinguish between these possibilities, I explored the patterns by which the juvenile rudiment is formed as well as the variation among juveniles approximately 1 day after metamorphosis in 19 echinoid taxa covering a broad taxonomic range including cidaroids, diadematids, irregular echinoids (spatangoids and clypeasteroids), arbaciids, temnopleurids, echinometrids and strongylocentrotids. Most of the material for analysis of juveniles was obtained by the author. Additional information was gathered from classical studies of metamorphosis. Data were collected on the number and shape of dorsal pedicellariae, juvenile and adult spines, primary and secondary podia, and juvenile test shape. When possible multiple individuals within a species were examined, revealing no or only minor trait variation. These data were mapped on a well-resolved phylogeny established from adult characters.

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Hata, Masayoshi. « An approach to the phylogeny of the order Echinoida using interf amily hybrids ». Zygote 8, S1 (décembre 1999) : S88—S89. http://dx.doi.org/10.1017/s0967199400130527.

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Order Echinoida in Japan is now classified into the following five families: Temnopleuridae, Toxo-pneustidae, Strongylocentrotidae, Echinometridae and Parasaleniidae. With the exception of the Parasaleniidae, four of the families are commonly found in shallow waters in Japan. Interrelationships among these four families have been extensively studied by many workers using morphological criteria or at the biochemical and molecular levels, and four different theories have been proposed (Jensen, 1981; Smith, 1984; Mortensen, 1928–1951; Shigei, 1986; Matsuoka, 1988). To examine these theories, I attempted to obtain hybrids using 14 species (4 species of the family Temnopleuridae: Temnopleurus toreumaticus, Temnopleurus hardwickii, Temnopleurus reeversii and Mespilia globulus; 3 species of the family Toxopneustidae: Toxopneustes pileolus, Tripneustes gratilla and Pseudoboletia maculata; 4 species of the family Strongylocentrotidae: Strongylocentrotus intermedius, Strongylocentrotus nudus, Hemicentrotus pulcherrimus and Pseudocentrotus depressus; and 3 species of the family Echinometridae: Anthocidaris crassispina, Echinostrephus aciculatus and Echinometra mathaei).

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Ghyoot, Marianne, Chantal De Ridder et Michel Jangoux. « Fine structure and presumed functions of the pedicellariae of Echinocardium cordatum (Echinodermata, Echinoida) ». Zoomorphology 106, n^o 5 (mars 1987) : 279–88. http://dx.doi.org/10.1007/bf00312002.

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Linse, Katrin, Lisa J. Walker et David K. A. Barnes. « Biodiversity of echinoids and their epibionts around the Scotia Arc, Antarctica ». Antarctic Science 20, n^o 3 (19 mai 2008) : 227–44. http://dx.doi.org/10.1017/s0954102008001181.

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AbstractThe Scotia Arc, linking the Magellan region with the Antarctic Peninsula, comprises young and old islands both near continents and isolated, and is the only semi-continuous link between cool temperate and Antarctic environments. It is an ideal region for studies on how marine biodiversity changes across an extended transition zone. Echinoids (sea urchins) and their associated epibionts were found across depths from 91–1045 m, with 19 species from shelf and four from slope depths. The 23 species from 38 trawls represent 31% of all echinoid species known from the Southern Ocean and 38% of the shelf/upper slope echinoids. The specimens collected comprise representatives of the five families Cidaridae, Echinidae, Temnopleuridae, Schizasteridae and Pourtalesiidae. Echinoids are probably a good model for how well we know Antarctic shelf and slope megabenthos; none of the species we report are new to science but we found nine (39%) of our study species present at new localities, some thousands of kilometres from previous findings. New biogeographic ranges are illustrated forCtenocidaris gigantea,C. nutrix,C. spinosa,Abatus curvidens,A. ingens,A. shackletoni,Amphineustes rostratus,Tripylaster philippiandPourtalesia aurorae. Southern Ocean echinoids show eurybathy as the mean depth range of our study species was 1241 m and only one was at less than 500 m. The current view of echinoid dominance of super-abundance in the shallows seems to be not transferable to shelf and slope depths as only one of 38 trawls was dominated by echinoids. Current knowledge on maximum sizes in Antarctic echinoids seems to be good as our morphometric measurements were mainly within known size ranges. Regular echinoids increased predictably in mass with increasing test length, apart fromCtenocidaris spinosa. Tissue mass of cidaroid species was ~17%, but across irregular species varied from 17.7–8.9%. No epibionts were found on irregular echinoids or Echinidae but 70 cidaroids examined carried 51 species representing ten classes. Many of these species are reported as cidaroid epibionts for the first time. Cidaroids and their epibionts constituted > 38% of the total macrofaunal richness in the trawls they were present in. Echinoids and their epibionts clearly contribute significantly to Southern Ocean biodiversity but are minor components of biomass except in the shallows.

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Hodin, Jason, Keegan Lutek et Andreas Heyland. « A newly identified left–right asymmetry in larval sea urchins ». Royal Society Open Science 3, n^o 8 (août 2016) : 160139. http://dx.doi.org/10.1098/rsos.160139.

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Directional asymmetry (DA) in body form is a widespread phenomenon in animals and plants alike, and a functional understanding of such asymmetries can offer insights into the ways in which ecology and development interface to drive evolution. Echinoids (sea urchins, sand dollars and their kin) with planktotrophic development have a bilaterally symmetrical feeding pluteus larva that undergoes a dramatic metamorphosis into a pentameral juvenile that enters the benthos at settlement. The earliest stage of this transformation involves a DA: a left-side invagination in mid-stage larvae leads to the formation of the oral field of the juvenile via a directionally asymmetric structure called the echinus rudiment. Here, we show for the first time in two echinoid species that there is a corresponding DA in the overall shape of the larva: late-stage plutei have consistently shorter arms specifically on the rudiment (left) side. We then demonstrate a mechanistic connection between the rudiment and arm length asymmetries by examining rare, anomalous purple urchin larvae that have rudiments on both the left and the right side. Our data suggest that this asymmetry is probably a broadly shared feature characterizing ontogeny in the class Echinoidea. We propose several functional hypotheses—including developmental constraints and water column stability—to account for this newly identified asymmetry.

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Stien, A., HP Leinaas, O. Halvorsen et H. Christie. « Population dynamics of the Echinomermella matsi (Nematoda)-Strongylocentrotus droebachiensis (Echinoida) system:effects on host fecundity ». Marine Ecology Progress Series 171 (1998) : 193–201. http://dx.doi.org/10.3354/meps171193.

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Stien, A., HP Leinaas, O. Halvorsen et H. Christie. « Population dynamics of the Echinomermella matsi (Nematoda)-Strongylocentrotus droebachiensis (Echinoida) system:effects on host fecundity ». Marine Ecology Progress Series 163 (1998) : 193–201. http://dx.doi.org/10.3354/meps163193.

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Biermann, C. H. « The molecular evolution of sperm bindin in six species of sea urchins (Echinoida : Strongylocentrotidae) ». Molecular Biology and Evolution 15, n^o 12 (1 décembre 1998) : 1761–71. http://dx.doi.org/10.1093/oxfordjournals.molbev.a025902.

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Märkel, Konrad, et Ursula Röser. « Functional anatomy of the valves in the ambulacral system of sea urchins (Echinodermata, Echinoida) ». Zoomorphology 111, n^o 3 (septembre 1992) : 179–92. http://dx.doi.org/10.1007/bf01632907.

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Matsuoka, Norimasa. « Further immunological study on the phylogenetic relationships among sea-urchins of the order echinoida ». Comparative Biochemistry and Physiology Part B : Comparative Biochemistry 84, n^o 4 (janvier 1986) : 465–68. http://dx.doi.org/10.1016/0305-0491(86)90107-0.

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M�rkel, Konrad, Ursula R�ser et Michael Stauber. « The interpyramidal muscle of Aristotle's lantern : its myoepithelial structure and its growth (Echinodermata, Echinoida) ». Zoomorphology 109, n^o 5 (juillet 1990) : 251–62. http://dx.doi.org/10.1007/bf00312192.

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Zachos, Louis G., et Daniel Levin. « Rediscovery of figured Paleogene echinoid specimens from Clark and Martin (1901) ». Journal of Paleontology 84, n^o 1 (janvier 2010) : 148. http://dx.doi.org/10.1666/09-094.1.

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Clark and Martin (1901), in their study of the Paleogene deposits of Maryland, figured drawings of a fragment of a spatangoid echinoid from the Lower Eocene Nanjemoy Formation and a broken echinoid spine from the Upper Paleocene Aquia Formation. Echinoids are an important element of Paleogene faunas in the eastern United States, but these are the only reported occurrences of this age from either Maryland or Virginia and are therefore significant to the understanding of the evolution and paleogeography of echinoids in this region. The figured specimens were attributed to collections at Johns Hopkins University, but without catalog numbers. During study of the paleobiology collections of the National Museum of Natural History (NMNH), Smithsonian Institution, two vials were discovered with small, handwritten labels referencing the figure numbers in Clark and Martin (1901). The contained specimens were recognized as those figured in the report. They have been cataloged in the NMNH collections as follows:

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Dudicourt, Jean-Christophe, Didier Neraudeau, Philippe Nicolleau, Luc Ceulemans et Frédéric Boutin. « An outstanding fauna of marsupiate echinoids in the Pliocene of Vendée (western France) ». Bulletin de la Société Géologique de France 176, n^o 6 (1 novembre 2005) : 545–57. http://dx.doi.org/10.2113/176.6.545.

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Abstract New investigations in the Pliocene deposits of Challans (Vendée) have allowed to collect more than 3000 marsupiate echinoids, remarkably preserved. So, apical systems, especially the marsupium of the breeding temnopleurids T. (V.) bigoti and C. bardini, have been described and figured for the first time with complete specimens. Two new marsupiate species have been described: Arbacina hugueti nov. sp., third marsupiate species of the genus Arbacina to be known in the Neogene of western France after A. emmae NÉRAUDEAU, 2003 from the Messinian of Brittany and A. pareyni ROMAN, 1983 from the Pliocene of Normandy; Tremaster romani, new species and genus of temnopleurid, characterised by an uncommon supra-ambital tuberculation, with excressences of the test surrounding scrobiculated tubercles. A third new marsupiate echinoid, Coptechinus sp. A, has been found too, but it is very difficult to know if it is a new species or a new morphotype of C. bardini. Contrarily to previous interpretations, this study points out the high diversity of western European Neogene marsupiate echinoids, a diversity comparable to the one of Australian Neogene marsupiate echinoids. However, breeding species from Australia and western Europe are clearly different and similarities exist between these two marsupiate echinofaunas at the family level only. Indeed, both in Australia and western Europe, the breeding species of echinoids mainly belong to the temnopleurid family, with the austral genus Paradoxechinus, on the one side, the north European genera Temnotrema and Coptechinus, on the other side. Moreover, the arbaciids consist of three marsupiate species of the genus Arbacina in Europe when no breeding species of this family exist in Australia. On the contrary, several breeding irregular echinoids have been found in the Australian Tertiary deposits (Spatangoids and Clypeasteroids) when not any marsupiate irregular echinoid has been discovered at present in the western Europe Neogene deposits.

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Pavlova, L. V. « Estimation of foraging on the sea urchin Strongylocentrotus droebachiensis (Echinoidea : Echinoida) by the red king crab Paralithodes camtschaticus (Malacostraca : Decapoda) in coastal waters of the Barents Sea ». Russian Journal of Marine Biology 35, n^o 4 (juillet 2009) : 288–95. http://dx.doi.org/10.1134/s1063074009040038.

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KANAZAWA, K., M. SAITOH, N. WAKAYAMA, M. OBUCHI, S. NAKACHI et A. KROH. « A project for analyzing the ecology and phylogeny of western Pacific echinoids ». Zoosymposia 15, n^o 1 (21 octobre 2019) : 83–87. http://dx.doi.org/10.11646/zoosymposia.15.1.9.

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In 2017 we started a project to analyze the ecology and phylogeny of western Pacific echinoids. As the first step, we are establishing methods to infer their phylogenetic relationships using molecular data; we developed effective methods to obtain complete mitochondrial DNA sequences, and determined their effectiveness in phylogenetic analysis. We have also been gathering data concerning the ecology and systematics of Japanese extant echinoids, which arguably has among the highest genus-level diversities in the West Pacific or perhaps even in the world. We have collected 58 species from middle and southern Japan representing 48 genera. In the next year, we will collect sea urchins from northern Japan, and within 2 years we will finish collecting data on ecology and systematics of Japanese echinoids, and provide a set of standardized data that will be useful for many researchers studying western Pacific echinoids. At that time, we will start comparative analyses of echinoid faunas distributed in the western Pacific.

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Stiefel, Klaus, et Glyn Barrett. « Sea Urchins as an Inspiration for Robotic Designs ». Journal of Marine Science and Engineering 6, n^o 4 (10 octobre 2018) : 112. http://dx.doi.org/10.3390/jmse6040112.

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Neuromorphic engineering is the approach to intelligent machine design inspired by nature. Here, we outline possible robotic design principles derived from the neural and motor systems of sea urchins (Echinoida). Firstly, we review the neurobiology and locomotor systems of sea urchins, with a comparative emphasis on differences to animals with a more centralized nervous system. We discuss the functioning and enervation of the tube feet, pedicellariae, and spines, including the limited autonomy of these structures. We outline the design principles behind the sea urchin nervous system. We discuss the current approaches of adapting these principles to robotics, such as sucker-like structures inspired by tube feet and a robotic adaptation of the sea urchin jaw, as well as future directions and possible limitations to using these principles in robots.

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Nezlin, Leonid P., et Vladimir V. Yushin. « The digestive tract of the echinopluteus of Echinocardium cordatum (Echinodermata, Echinoida) : its ultrastructure and innervation ». Canadian Journal of Zoology 72, n^o 12 (1 décembre 1994) : 2090–99. http://dx.doi.org/10.1139/z94-280.

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The digestive tract of the echinopluteus of Echinocardium cordatum consists of a tubular oesophagus, spherical stomach, and large hemispherical intestine. The oesophagus is constructed from cells of one ultrastructural type and has subepithelial muscles oriented circumferentially and longitudinally. The cardiac and pyloric sphincters separating the stomach from the oesophagus and intestine, as well as the anal sphincter, consist of myoepithelial cells and subepithelial muscles. The cells of both the stomach and intestine are able to absorb nutrients and phagocytize food. Neuron-like cells were detected around the mouth, in the oesophageal epithelium, and around the anal opening. Axonal trunks pass at the base of the oesophageal epithelium and around the sphincters. The rest of the digestive tract is innervated by solitary axons. Catecholamine-containing neurons were found inside the lower lip ganglion, in the two suboral ganglia, and around the anal opening.

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Stauber, Michael. « The lantern of Aristotle : organization of its coelom and origin of its muscles (Echinodermata, Echinoida) ». Zoomorphology 113, n^o 2 (juin 1993) : 137–51. http://dx.doi.org/10.1007/bf00403091.

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ZIEGLER, ALEXANDER. « Broad application of non-invasive imaging techniques to echinoids and other echinoderm taxa* ». Zoosymposia 7, n^o 1 (12 décembre 2012) : 53–70. http://dx.doi.org/10.11646/zoosymposia.7.1.6.

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Tomographic imaging techniques such as micro-computed tomography (μCT) and magnetic resonance imaging (MRI) permit the gathering of digital anatomical data from whole animal specimens non-invasively. The resulting datasets can be used for direct observation of the two-dimensional tomographic image data as well as for manual and semi-automated three-dimensional modelling. Freshly fixed specimens as well as preserved museum material can be successfully analyzed using this approach, giving the zoomorphologist a powerful tool for large-scale comparative studies. In order to demonstrate the principle suitability of non-invasive imaging in echinoderm research, μCT scans of 199 and MRI scans of 92 sea urchin (Echinodermata: Echinoidea) species were acquired, resulting in a total of 203 analyzed echinoid species. The taxa selected represent 50 of the currently recognized 60 extant sea urchin families. The present article lists all species that have been analyzed so far and provides information about the scanning parameters employed for each dataset. Furthermore, the workflow established to generate three-dimensional models of sea urchins is outlined. Using a number of examples from μCT as well as MRI scans performed on echinoids, the potential of the systematic approach described here is highlighted. Finally, the suitability of non-invasive imaging techniques for the study of other echinoderm taxa is assessed based on multimodal datasets of representative species.

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SAUCÈDE, THOMAS, JEAN-CHRISTOPHE DUDICOURT et PHILIPPE COURVILLE. « Description of two new fossil echinoids (Echinodermata : Echinoidea) from the Early Hauterivian (Early Cretaceous) of the Paris Basin (France) ». Zootaxa 3512, n^o 1 (10 octobre 2012) : 75. http://dx.doi.org/10.11646/zootaxa.3512.1.5.

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Two new echinoid genera and species, Salvaster roberti gen. et sp. nov. and Pygolampas edita gen. et sp. nov. are de-scribed. They were collected in the Calcaires à Spatangues Formation (CSF) that consists of limestone and clay sedimentsdeposited in the southeast of the Paris Basin (France) during the Early Hauterivian (Early Cretaceous). The CSF is datedfrom the Acanthodiscus radiatus chronozone, a time-interval of overall high sea level in Western Europe, but it yields arich shallow-water fossil fauna mostly represented by benthic invertebrates. Of the 54 echinoid species ever described inthe CSF, 26 species are recognized here. They are distributed into 16 different families, among which regular (13 species)and irregular (13 species) echinoids are represented in equal proportion. This work confirms the high level of echinoid diversity in the CSF for that time-period.

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Kroh, Andreas. « Echinoids (Echinoidea, Echinodermata) from Štramberk-type limestones in Poland ». Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 276, n^o 2 (1 mai 2015) : 213–27. http://dx.doi.org/10.1127/njgpa/2015/0489.

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SAUCÈDE, THOMAS, RICH MOOI et BRUNO DAVID. « Phylogeny and origin of Jurassic irregular echinoids (Echinodermata : Echinoidea) ». Geological Magazine 144, n^o 2 (19 décembre 2006) : 333–59. http://dx.doi.org/10.1017/s0016756806003001.

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A phylogenetic analysis of Jurassic irregular echinoids is realized to explore the origin and early evolution of this important subset of echinoids. The phylogeny is based on 39 characters and considers data from apical system architecture, the corona including tuberculation and spines, Aristotle's lantern, and general test shape. Results corroborate the monophyly of Irregularia, and clarify the phylogenetic interrelationships existing between the main groups of irregular echinoids. Specializations of the Aristotle's lantern, spines, tubercles and phyllodes constitute the apomorphies for different taxa, as for the whole of Irregularia. The phylogenetic signal yielded by these characters highlights the importance of the environmental context of the origin and diversification of irregular echinoids. The definition of ‘irregularity’ is re-examined, rejecting exocyclism and characters of the apical system as appropriate synapomorphies, and stressing the importance of other characters, particularly the high density and small size of tubercles and spines. A new clade name, Infraclypeidae [P], and phylocode designations (stem-based diagnoses) are proposed for the clades Irregularia, Eognathostomata, Microstomata, Neognathostomata and Atelostomata. Other groupings formerly used (Pygasteroida, Galeropygidae and Menopygidae) are considered paraphyletic.

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Märkel, Konrad, et Ursula Röser. « Ultrastructure and organization of the epineural canal and the nerve cord in sea urchins (Echinodermata, Echinoida) ». Zoomorphology 110, n^o 5 (septembre 1991) : 267–79. http://dx.doi.org/10.1007/bf01633099.

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