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1.
Cornulites sp. and Fistulipora przhidolensis formed a symbiotic association in the Pridoli (latest Silurian) of Saaremaa Island, Estonia. This Cornulites sp.–F. przhidolensis association is the youngest example of cornulitid–bryozoan symbiosis. Symbiosis is indicated by intergrowth of both organisms. The cornulitids are completely embedded within the cystoporate bryozoan colony, leaving only their apertures free on the growth surface of bryozoan. In terms of food competition, this association could have been slightly harmful to F. przhidolensis as Cornulites sp. may have been a kleptoparasite. There may have been a small escalation in the evolution of the endobiotic life mode of cornulitids as the number of such associations increased from the Ordovician to Silurian. It is likely that Palaeozoic bryozoan symbiosis reached its maximum in the Late Ordovician. Most of the symbiotic bryozoans in the Palaeozoic are trepostomes, and the diversity of symbiotic associations was also greatest among trepostomes.  相似文献   

2.
Abstract: Numerous new cases of preserved shell microstructure were discovered in molluscs from the Middle Cambrian Gowers Formation (Ptychagnostus atavus/Peronopsis opimus Zone, Floran Stage) in the Georgina Basin, Australia. The new data provide further evidence that, by the Middle Cambrian, molluscan shell microstructures were diverse, and many molluscs had a complex shell with multiple types of shell microstructure. In addition, many new occurrences of laminar microstructures are described herein. For many, the nature of these laminar microstructures is not known, but in three species the microstructure is foliated calcite, and in at least two the microstructure is more likely to have been calcitic semi‐nacre, a type of microstructure known in brachiopods and bryozoans but unknown in modern molluscs. This commonality among these three closely related lophotrochozoans underscores a similar mechanism of biomineralization. Moreover, these observations suggest a prevalence of calcite‐shelled lineages among molluscs from the Middle Cambrian, a time of calcite seas. In addition, the broad occurrence of laminar, nacre‐like microstructures in many of these fossils reveals how widespread these strong (fracture‐resistant) microstructures were in Middle Cambrian molluscs. Additionally, a few specimens of Yochelcionella preserve imprints of a bilaterally symmetrical pair of muscle scars. New taxa described here include Corystos thorntoniensis gen. et sp. nov., Yochelcionella snorkorum sp. nov., Yochelcionella saginata sp. nov., and Anhuiconus? agrenon sp. nov.  相似文献   

3.
Conodonts, thelodonts and acanthodians have previously been collected from the P?ídolí of Shropshire (Welsh Borderland) from bone beds such as the Ludlow Bone Bed. In general, specimens collected from these types of deposit are very abraded and make taxonomic studies difficult. This contribution describes well preserved thelodont microelements from two samples from the Downton Castle Sandstone Formation (P?ídolí, Silurian) of the Much Wenlock area of Shropshire. Head scales, a wide variety of transitional scales, and pore scales of the lateral line sensory canals of the thelodont Paralogania ludlowiensis (Gross) are described for the first time. A new acanthodian Nostolepis linleyensis sp. nov. and elements from the apparatus of the conodont Ozarkodina?hemensis sp. nov. are documented from the same samples. The thelodonts in both samples are typical of upper Ludlow–P?ídolí faunas from across the Welsh Borderland, and are also present in smaller numbers in the Ludlow Series of Gotland, Sweden, Saaremaa Island, Estonia, and in Latvia and Lithuania. The conodont O? hemensis sp. nov. is restricted to the Much Wenlock area of Shropshire. The co-occurrence of well preserved elements of conodonts and thelodonts suggests that they were deposited fairly rapidly with little or no re-working and that a restricted marine environment prevailed in the early P?ídolí in the Much Wenlock area of Shropshire.  相似文献   

4.
The species of the snail genus Everettia in the Malaysian state of Sabah are superficially similar and difficult to distinguish by their shells. This paper presents new data on the taxonomy and distribution of Everettia in Sabah that have accumulated since the revision by Godwin‐Austen in 1891. By using morphological and molecular phylogenetic approaches, we reveal at least seventeen species of Everettia in Sabah, of which eleven are new to science, namely: Everettia layanglayang sp. nov. , Everettia lapidini sp. nov. , Everettia paulbasintali sp. nov. , Everettia occidentalis sp. nov. , Everettia jasilini sp. nov. , Everettia safriei sp. nov. , Everettia interior sp. nov. , Everettia jucundior sp. nov. , Everettia planispira sp. nov. , Everettia monticola sp. nov. , and Everettia dominiki sp. nov. , and one new subspecies, namely, Everettia corrugata williamsi ssp. nov. Phylogenetic analysis of mitochondrial COI and 16S, and nuclear ITS‐1 sequences demonstrates the monophyly of most of the morphologically well‐defined species. Our results show that certain aspects of classical morphology‐based taxonomy for Everettia species, especially with regard to the unique combination of shell surface sculptures, animal head colour, and mantle pigmentation, are solid. A dichotomous key to the Sabah species and subspecies of Everettia is provided. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 157 , 515–550.  相似文献   

5.
Abstract: Although their record extends back to the Early Ordovician, the occurrence of fossil starfish (Echinodermata: Asteroidea) is dependent almost exclusively upon horizons of exceptional preservation. Thus, asteroids found in Silurian obrution deposits of the English Midlands and Welsh Borderlands are particularly significant to an understanding of the early diversity of the group. Six species are described here: Hudsonaster? carectum sp. nov. (Hudsonasteridae), from the lower part of the Lower Elton Formation; and, from the Much Wenlock Limestone Formation, the hudsonasterids Doliaster brachyactis gen. et sp. nov. and Siluraster? ketleyi (Spencer, 1916), the lepidasterids Lepidaster grayi Forbes, 1850 and Lepidactis wenlocki Spencer, 1918, and the palasterinid Palasterina orchilocalia sp. nov. Though few in number, they show a diverse range of body morphologies when compared with Ordovician taxa: L. wenlocki had long, slender rays when fully grown whereas D. brachyactis is the first asteroid with the short‐rayed body form of extant cushion stars. Most distinctive of all is L. grayi, the earliest multiradiate taxon known, all complete specimens of which have 13 rays. This morphological variety is interpreted as indicating that by the Early Silurian starfish were exploiting a wide range of feeding habits and ecological niches.  相似文献   

6.
Kiisortoqia soperi gen. et sp. nov. is an arthropod species from the Early Cambrian Sirius Passet Lagerstätte of North Greenland. A head, incorporating four appendiferous segments and biramous limbs, with an anteroposteriorly compressed basipod with a spine bearing median edge, support the euarthropod affinities of K. soperi gen. et sp. nov. Similarities with ‘short great appendage’ arthropods, or megacheirans, like the nine‐segmented endopod, and the flap‐ or paddle‐like exopod, may be symplesiomorphies. The antennula, however, resembles in composition and size the anteroventral raptorial appendage of anomalocaridids. Thus, the morphology of K. soperi gen. et sp. nov. provides additional support for the homologization of the anomalocaridid ‘great appendage’ with the appendage of the antennular or deutocerebral segment of extant Euarthropoda. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 477–500.  相似文献   

7.
Hybodontoid and nonhybodontoid sharks are described from the Lower Triassic Vega‐Phroso Siltstone Member of Sulphur Mountain Formation on the basis of newly discovered material. The age of the classic fossil site ‘Wapiti Lake’ in the Canadian Rocky Mountains is discussed on the basis of new field data and one conodont found in association. Preliminary results suggest that these elasmobranch remains are between early Smithian and Spathian in age. Apart from the enigmatic genus Listracanthus and previously reported edestoids, the shark fauna consists of at least one hybodont, at least two questionable hybodontoid genera and an elasmobranch of enigmatic affinities, represented by peculiar denticles only and described as ‘genus A’incertae sedis. The presence of the only previously reported hybodont genus, cf. Palaeobates, is erroneous. The largest specimen represents the most complete Early Mesozoic shark known. The heterodonty of its dentition, fin spine morphology and the short, robust body shape imply it represents a member of a new family of shark, Wapitiodidae fam. nov. , and is described here as Wapitiodus aplopagus gen. et sp. nov. The unique dental morphology shows affinities to Polyacrodus but clearly differs in the complete lack of side cusps. Wapitiodus gen. nov. possesses a primitive fin spine structure. The tooth crowns are entirely blunt in the distal (posterior) tooth files, and are acuminate‐unicuspid in several anterior files. Tooth morphology, the shape of the basal cartilages, the proximal insertion of the fin spines and the pectoral fin structure are interpreted as diagnostic characters for this new genus, and possibly for the Wapitiodidae fam. nov. The majority of observed characters appear to be primitive and are reminiscent of Palaeozoic sharks, however, and these features include dorsal fin spine morphology and gross skull anatomy. A second species, provisionally placed in the same genus, is described as Wapitiodus homalorhizo sp. nov. Wapitiodus homalorhizo sp. nov. can be distinguished from W. aplopagus gen. et sp. nov. by the proportions of the fin spines, tooth morphology and possibly the body shape. Several isolated teeth and other fragmentary material are referred to either Wapitiodus gen. nov. sp. indet. or to ?Polyacrodus sp. (Polyacrodontidae gen. et sp. indet.). A third genus of elasmobranch (incertae sedis) is described as ‘Genus A’ and is recognized by its peculiar scales. © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society, 2007, 149 , 309–337.  相似文献   

8.
A fauna of provannid and provannid‐like shells is described from Upper Cretaceous seep carbonates in Hokkaido, Japan. We describe two new provannid species, Provanna tappuensis sp. nov. and Desbruyeresia kanajirisawensis sp. nov. , with preserved protoconchs of unquestionable provannid type with decollate apex. This material confirms the occurrence of Provannidae as early as the Middle Cenomanian. We also describe Hokkaidoconcha gen. nov. and a new family Hokkaidoconchidae fam. nov. , with two named species, H. hikidai sp. nov. and H. tanabei sp. nov . Hokkaidoconchidae are possibly related to the Provannidae, judging from a similar, but not decollate larval shell, although the juvenile teleoconch whorls differ in being of a general cerithimorph appearance and the details of the aperture are unknown. Furthermore, we review the published fossil record of Provannidae and Abyssochrysidae, and we consider that in those older than the Eocene, there is no evidence preserved that unequivocally supports a position there. The Jurassic Acanthostrophia acanthica from Italy seems to be the oldest known record of Abyssochrysidae, and the most reliable occurrence of the family, older than from the Miocene. Other fossil, pre‐Miocene species that have been classified in the Abyssochryssidae are provisionally referred to Hokkaidoconchidae. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 154 , 421–436.  相似文献   

9.
Sediment traps were placed in the water column both inside and in the vicinity of three northwestern Mediterranean submarine canyons. The sediment traps with 12 rotary collectors were deployed on mooring lines 30 and 500 m above the sea floor, and were sampled fortnightly. Polychaete worms (Anelida) and hydromedusae (Cnidaria) were the most abundant zoological taxa captured. Whereas hydromedusae and three of the polychaete species were clearly planktonic organisms, 16 polychaete species were adult benthic forms without special adaptations for swimming, and sometimes also had a large biomass. Four of the 19 polychaete species are described as new species: Aricidea (Allia) longisetosa sp. nov. , Paradoneis hirsuta sp. nov. , Ophelina margaleffi sp. nov. , and Exogone (Parexogone) canyonincolae sp. nov. The rich collection of polychaetes obtained leads us to postulate that these animals are supported by a continuous flux of organic matter, and that they are adapted to the rigorous physical conditions that may occur between the seafloor and the bottom water. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 1–21.  相似文献   

10.
Although aquatic caterpillars are a globally rare lifestyle, we have found them in multiple, independent lineages of the endemic moth genus Hyposmocoma across all of the Hawaiian Islands with flowing water. We formally describe 11 new species of Hyposmocoma that belong to four different larval case types: cone, bugle, medium burrito, and large burrito: Hyposmocoma kahamanoa sp. nov. from Oahu Island, Hyposmocoma kamakou sp. nov. from Molokai Island, Hyposmocoma kahaiao sp. nov. , Hyposmocoma waihohonu sp. nov. , and Hyposmocoma moopalikea sp. nov. from Maui Island, and Hyposmocoma aumakuawai sp. nov. , Hyposmocoma eepawai sp. nov. , Hyposmocoma ipowainui sp. nov. , Hyposmocoma kawaikoi sp. nov. , Hyposmocoma uhauiole sp. nov. , and Hyposmocoma wailua sp. nov. from Kauai Island. We also illustrate and describe in detail the aquatic case‐bearing larva of Hyposmocoma kahamanoa. Despite having similar ecologies as algae and lichen grazers at and below the water line of streams, prior research indicates that species with each case type constitute an independent lineage, with terrestrial sister taxa, and therefore the different groups of species bearing unique case types each represent an independent aquatic invasion. The case‐bearing larvae often occur sympatrically, and on Kauai even species with similar case‐types occur together, suggesting complex patterns of speciation and either past periods of isolation or sympatric speciation. Phylogenetic analysis of 2243 base pairs from two nuclear and one mitochondrial gene for 18 species confirm that each species is endemic to a single volcano, and that morphological divergence within case‐types has not been dramatic. Diversification has been complex, and superficially similar case type lineages are not all monophyletic. Kauai, the oldest but smallest of the major high islands, supports more species in the aquatic guild than any other island, thus island age, rather than size, may be important in generating diversity in this group. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 162 , 15–42.  相似文献   

11.
We describe a weakly biomineralized non‐trilobite artiopodan arthropod from the Guzhangian Weeks Formation of Utah. Falcatamacaris bellua gen. et sp. nov. is typified by a thin calcitic cuticle, broad cephalon without eyes or dorsal ecdysial sutures, an elongate trunk with distinctively sickle‐shaped pleural spines and a long tailspine with a bifurcate termination. The precise affinities of Falcatamacaris gen. nov. are problematic due to the presence of unique features within Artiopoda, such as the peculiar morphology of the pleural and posterior regions of the trunk. Possible affinities with aglaspidid‐like arthropods and concilitergans are discussed based on the possession of 11 trunk tergites, edge‐to‐edge articulations and overall body spinosity. The new taxon highlights the importance of the Weeks Formation Konservat‐Lagerstätte for further understanding the diversity of extinct arthropod groups in the upper Cambrian.  相似文献   

12.
Originally described as an inarticulate brachiopod, and later even queried as a possible coral, the unique specimen of Crania sedgwickii Davidson, 1848, from the Much Wenlock Limestone Formation (Silurian) of England is now recognised as an operculum belonging to the Hyolitha. In detail its affinities remain unclear, since it cannot be matched with any known hyolith, and it probably represents a new genus. Its morphology incorporates a combination of features suggestive of both the Order Hyolithida and the Orthothecida, but its closest relationships appear to be with the latter group. Records of C. sedgwickii from Gotland, Sweden, probably refer to true craniacean brachiopods and thus bear no relationship to the English specimen.  相似文献   

13.
A recent survey of the freshwater streams of the Mecula and Yao mountains in the Niassa province of Mozambique resulted in the discovery of a new freshwater crab species. This species is genetically and morphologically distinct from described species from Mozambique or its neighbouring countries, and is described as P otamonautes bellarussus sp. nov. In addition, a new semi‐terrestrial burrowing freshwater crab P otamonautes flavusjo sp. nov. from the Highveld of the Mpumalanga province in South Africa is described based on unique genetic and morphological characters. The phylogenetic affinities of the two new species in relation to the described eastern and southern African Potamonautes species is determined and the biogeographic implications are discussed. © 2014 The Linnean Society of London  相似文献   

14.
We describe the oldest Paucituberculata marsupials, from the La Barda and Las Flores localities (Argentina; Late Palaeocene, and Early–Middle Eocene), as well as from the Itaboraí Basin (Brazil; Late Palaeocene). The new taxa are represented by very scarce, although well‐preserved, dental remains. A parsimony analysis was performed in order to evaluate the phylogenetic affinities of these taxa. Representatives of both Riolestes capricornicus gen. et sp. nov. and Bardalestes hunco gen. et sp. nov. appear to be basal paucituberculatans, and their molar features give clues on the early evolution of the representatives of this order. Within the Paucituberculata we recognize two major clades: Caenolestoidea and Palaeothentoidea. We conclude that ‘pseudodiprotodont’ marsupials of the traditional literature (i.e. Polydolopimorphia + Paucituberculata) do not form a natural group. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 867–884.  相似文献   

15.
In this contribution a new representative of the taxon Meidiama Marcus, 1946, Meidiama uruguayensis sp. nov. , from Uruguay, is described, as are six more new species, for which three new genera are proposed: Dreuxiola philippi gen. nov. sp. nov. , from the French subantarctic archipelago Kerguelen; Yorknia aprostatica gen. nov. sp. nov. ; Serrula byronensis gen. nov. sp. nov. ; Serrula maxillaria sp. nov. ; Serrula concharum sp. nov. ; and Serrula acuta sp. nov. , from eastern Australia and Tasmania. Arguments are presented to propose a new taxon to contain these new species, rather than include them in the Archimonocelididae Meixner, 1938 (of which Meidiama has been considered a member so far), as well as to remove the Calviriinae Martens & Curini‐Galletti from the Archimonocelididae to become a separate taxon Calviriidae. Possible autapomorphies for the three families are discussed. It is also concluded that, with the present state of our knowledge, no sound indications can be given about close relationships. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 759–773.  相似文献   

16.
The jumping spider genus Onomastus Simon, 1900 is revised. Four new species: Onomastus indra sp. nov. , Onomastus kaharian sp. nov. , Onomastus pethiyagodai sp. nov. , and Onomastus rattotensis sp. nov. are described. Parsimony analysis of 26 morphological characters supported the monophyly of Onomastus. Lyssomanes is sister to Onomastus. Onomastus separates into two clades: the widespread South‐East Asia clade and the South Asia clade. The South Asia clade is restricted to the Sri Lanka–Western Ghats biodiversity hotspot. Species of the South Asia clade appear to be spot endemics, highly in danger of extinction because of habitat loss and climate change. Male palps are complex and species‐specific, suggesting rapid divergent evolution. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 159 , 711–745.  相似文献   

17.
Exceptionally well‐preserved Late Triassic unionoids from Silesia, Poland, show prominently ornamented juvenile shells and umbonal muscle attachments that are similar to Margaritifera, which are anatomically the least derived among extant unionoids. Their phosphatized (originally chitinous and impregnated with calcium phosphate) gill supports lacked transverse connections, and occasionally some of them were separated from others, being thus at the filibranch grade, like their trigonioid ancestors. Several separate small foot elevator attachments in these unionoids indicate Trigonodidae adaptation to marine or brackish water, in which the original trigonioid strong single attachment was already split into two in the Early Triassic. The ribbing of juvenile shells suggests a change to deeper infaunal life for juvenile stages, and generally less efficient near‐surface locomotion, with a wedge‐like foot, in adults. Much later the unionoids became eulamellibranchial, which promoted the brooding of the fish that their larvae parasitize. To accomodate the classification of the order under this scenario of evolutionary changes, a new suborder Silesunionina is proposed for its filibranch members. It includes the Silesunionidae fam. nov. , with the location of umbonal muscles similar to that in the extant underived unionoids, and the Unionellidae fam. nov. , with umbonal muscles attached to the external wall of the umbonal cavity. The early Late Triassic (Carnian) Silesunio parvus gen. et sp. nov. and latest Triassic (Rhaetian) Tihkia(?) silesiaca sp. nov. are proposed. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163 , 863–883.  相似文献   

18.
Species of the Amazonian jumping spider genus Soesiladeepakius Makhan are confirmed as non‐salticoids. Sequences of nuclear (28S, Actin) and mitochondrial (16S through NADH dehydrogenase subunit I, ‘16S‐ND1’) gene regions, analysed under parsimony and maximum likelihood, placed the genus within the lapsiines, closely related to Galianora Maddison. Additionally, six new species of this genus are herein described, namely Soesiladeepakius lyra sp. nov. , Soesiladeepakius retroversus sp. nov. , Soesiladeepakius arthrostylus sp. nov. , Soesiladeepakius gasnieri sp. nov. , Soesiladeepakius biarmatus sp. nov. , and Soesiladeepakius uncinatus sp. nov. , all from the Amazon region in Brazil. To test the monophyly of Soesiladeepakius within lapsiines, a cladistic analysis was carried out using a data matrix comprising 24 morphological characters scored for 12 taxa. The analysis resulted in two equally parsimonious trees of 29 steps. One of these trees is used to discuss the relationships among the species of Soesiladeepakius and character evolution. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 165 , 274–295.  相似文献   

19.
The Golden‐rayed Blue, Candalides noelkeri sp. nov. (Lepidoptera: Lycaenidae), from the Wimmera of western Victoria, Australia, is described and illustrated. The male and female genitalia and immature stages are figured, described and compared with those of Candalides heathi and C. xanthospilos. Candalides noelkeri sp. nov. is placed in the C. xanthospilos species‐group, being most closely allied to and allopatric with C. heathi. It is predominantly univoltine, with adults usually present from late November to early February. However, it has a facultative pupal diapause that gives rise to a partial overlapping second generation in mid‐summer. The species is ecologically specialized, monophagous and has a narrow geographical range, currently known only from two localities in a restricted area near Natimuk. Within this limited area it is restricted to flood plains bordering natural salt‐lakes where the larval food plant, a prostrate form of Myoporum parvifolium (Myoporaceae), grows as a low spreading ground cover plant. Morphological and geological evidence suggest a recent (late Pleistocene) allopatric speciation event between C. noelkeri sp. nov. and C. heathi. The small, peripheral spatial distribution of C. noelkeri sp. nov. implies that differentiation has been achieved by the founder effect, either through peripheral isolates speciation (peripatric speciation) or postspeciation dispersal, possibly as a result of a barrier created by the volcanic plains in western Victoria. Available information indicates that C. noelkeri sp. nov., Victoria's only endemic species of butterfly, is facing a high risk of extinction and accordingly its conservation status should be considered as Endangered. The most serious threat at the type locality is habitat change or succession caused by invasion of Melaleuca halmaturorum, which is creating a dense shaded paperbark forest that is reducing both the preferred open sunny microhabitat and the extent of the larval food plant. Recognition of C. noelkeri sp. nov. as a flagship taxon is likely to enhance the conservation of biodiversity in remnant flood plain/salt‐lake ecosystems of temperate south‐eastern Australia. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society, 2004, 81 , 275–299.  相似文献   

20.
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