NODAL SEPTA AND THE RIGIDITY OF AERIAL SHOOTS OF EQUISETUM HYEMALE

The biomechanical role of septate nodes (points of leaf attachment with transverse diaphragms of tissue) in the otherwise hollow aerial stems of Equisetum hyemale L. is examined by means of multiple resonance frequency spectra. Resonance frequencies were determined for intact shoots, as well as the same shoots through which metal needles were inserted to destroy septa at nodes. The elastic modulus (E) of shoots, before and after surgical manipulation, was calculated. Shoots with perforated septa had E values from 17 to 32% less than intact shoots. During winter months with subfreezing temperatures, shoots with intact nodal septa accumulated water (in the form of ice) in their internodal pith canals. Values of E calculated for a shoot with intact septa and internodal water, and for the same shoot without septa do not differ significantly. Calculations indicate that the mass of internodal water is a significant fraction of the mass sufficient to deflect and buckle shoots. The added mass of internodal water is sufficient to mask the actual elastic modulus of shoots. The data indicate that nodes with septa significantly influence the flexural rigidity of shoots, but that this influence changes as a function of the quantity of water found in pith cavities.     

The mechanical role of the endodermis in Equisetum plant stems

The endodermis of different species of the genus Equisetum has different configurations, two or one continuous layers or a sheath only around the vascular bundles. The question whether the endodermis contributes to the mechanical stability of the aerial shoots is investigated in two ways: In a direct approach, the endodermis of segments of E. hyemale was dissected longitudinally and the mechanical stability against ovalization measured as a function of the orientation of the cuts with respect to the forces applied. A comparative approach tested the mechanical stability of eight different species of Equisetum against ovalization of the cross-section for samples, which were either fully turgescent or had reduced turgor pressure. The double-layer endodermis substantially contributed to the mechanical stability of E. affinis and E. hyemale. Equisetum arvense, E. pratense, E. sylvaticum, and E. telmateja are mechanically stabilized by their single layer of endodermis at least under conditions of low turgor pressure.     

STRUCTURALLY PRESERVED SPHENOPHYTES FROM THE TRIASSIC OF ANTARCTICA: VEGETATIVE REMAINS OF SPACIINODUM,GEN. NOV.

Sphenophyte remains of Early-Middle Triassic age are described from silicified peat collected in the Transantarctic Mountains of Antarctica. The new sphenophyte, Spaciinodum collinsonii sp. nov., is represented by ribbed, jointed stems with characteristic pith and carinal canals. Stems are relatively small, ranging from 1.8–3.0 mm in diameter, lack secondary tissues, and are characterized by vallecular canals that are restricted to nodal regions. The internodal vascular system consists of 12–18 collateral bundles which alternate between successive internodes. A complete vascular ring is present in the nodal region and is surrounded by a continuous double endodermis. Xylem is endarch and composed of elements ranging from annular to reticulate. The Antarctic sphenophyte is compared with other Gondwana fossil articulates and extant Equisetum. Superficial stomata suggest affinities with modern Equisetum subgenus Equisetum; however, some anatomical differences preclude assignment with living species.     

Nordic equiseticolous Pyrenomycetes

The Pyrenomycete flora on Equisetum has been studied, mainly on Nordic material. With regard to frequency and host specificity these fungi can be divided into three groups, viz. 1) true Equisetum fungi; 2) common species but not restricted to Equisetum; 3) accidental species. An annotated list is given of the two first categories which comprise the following taxa. 1: Didymosphaeria equiseti–hiemalis, Phaeosphaeria berlesei, P. equiseti, Mycosphaerella equiseti, M. equiseticola, Scirrhia castagnei, S. silvalica , and probably Didymella equisetina. 2: Phaeosphaeria eustoma, P. fuckelii, Mycosphaerella cf. aspidii.
Two new taxa and one new combination are published, viz. Phaeosphaeria equiseti (Karst.) L. & K. Holm comb, nov., P. equiseti var. lindii L. & K. Holm var. nov., Scirrhia silvalica L. & K. Holm sp. nov.     

The origin of multiplacophorans – convergent evolution in Aculiferan molluscs

Abstract: Multiplacophorans are Palaeozoic (Silurian to Permian) stem group polyplacophorans with 17 shell plates in a particular arrangement of single terminal plates separated by three columns of plates forming five transverse rows. Their distinctive morphology has prompted disparate interpretations of their relationship to polyplacophorans. Some features are strikingly similar to crown group polyplacophorans and even to some living families. Here we describe two Devonian forms, Protobalanus spinicoronatus sp. nov., a hercolepadid from northeast Ohio, USA, and Hannestheronia australis gen. et sp. nov., a strobilepid from South Africa. Using the results from a Bayesian relaxed molecular clock to test competing scenarios of the relationship of multiplacophorans to crown group polyplacophorans, we demonstrate that multiplacophorans are stem group polyplacophorans in which certain characters of the crown group evolved convergently.     

Equisetum filum sp. nov. from the middle Jurassic of Yorkshire

Equisetum filum sp. nov. is described on compressed stems from the Bajocian, Middle Jurassic, of Yorkshire, northeast England. Its cuticle was known earlier as fragments called “Equisetum sp. A.” E. filum has slender unbranched stems which agree in many details with living species but differ in a few points. The free leaves bear stomata and seem to be solid. The internode has an unusual layer of subepidermal sclerids and seems to have no large internal air spaces. It contracts strongly at its base and the sheath enclosing it is corresponding thick.     

中国东南沿海裸鞘花水母一新属及三新种记述

记述了采自中国东南沿海台湾海峡南部、福建南部东山湾和福建东部宁德三都湾裸鞘花水母1新属——拟长管水母属Dipurenella gen.nov.和3新种,即刺胞海帽水母Halitiara knides sp.nov.,东山拟长管水母Dipurenella dongshanensis sp.nov.和粗管外肋水母Ectopleura crassocanalis sp.nov.。详细描述其形态特征,并与近似种进行比较。模式标本保存于厦门大学海洋与环境学院。     

中国草螟亚科三新种 (鳞翅目 :螟蛾科 )(英文)

记述了草螟亚科 3新种 :截突大草螟EschatatruncataSong&Chen ,角突大草螟EschatatricorniaSong&Chen和尖端银草螟PseudargyriaacutaSong&Chen。首描述了纵带双突草螟GirdhariataurommaKapur的雌性个体特征。对新种及新描述性别个体的外形和外生殖器进行了描述 ,并给出了其外生殖器特征图。截突大草螟Es chatatruncataSong&Chen的抱器背有一个短而末端平截的突起 ;角突大草螟EschatatricorniaSong&Chen的抱器瓣的背缘有一个三角形的突起 ;尖端银草螟PseudargyriaacutaSong&Chen的抱器端急尖 ,阳茎内有一组角状器。通过对布兰大草螟EschatableszynskiellaMinet的研究 ,认为上海大草螟E .shanghaiensisWang&Sung应为有效名 ,布兰大草螟EschatableszynskiellaMinet为上海大草螟的次级异名。     

A New Cheiracanthid Acanthodian Species from the Aruküla Regional Stage (Middle Devonian,Givetian) of the Eastern Main Devonian Field

A new cheiracanthid acanthodian species, Cheiracanthus flabellicostatus sp. nov., is described based on scales found in the beds of the Aruküla Regional Stage of Siverskiy and Zaitsevo localities of the Leningrad Region. It is distinguished from other members of the genus in the presence of a V-shaped eminence in the medial part of the scale crown and 8–10 large ribs branching into smaller ribs in the anterior part of the crown; large lacunas are observed at crossings of circular and ascending canals in the middle part of the scale neck.     

THREE NEW SPECIES OF CRAMBINAE (LEPIDOPTERA: PYRALIDAE) IN CHINA

Abstract Three new species of Crambinae from China, Eschata truncata Song & Chen, sp. nov., Eschata tricomia Song & Chen, sp. nov., Pseudargyria acuta Song & Chen, sp. nov. and the female of Girdharia tau-tomma Kapur are described, with figures and illustrations of genitalia provided. E. truncata resembles E. smithi Bleszynski, but valva with one short truncated process in costa; E. tricomia differed from all recorded species by valva with a triangular process on dorsum; P. acuta resembles P. marginepunctalis (Hampson), but with cucullus rapidly pointed and aedeagus with one group of comuti. E. bleszynskieila Minet is proposed as a junior synonym of E. shanghaiensis Wang & Sung.     

The Hawaiian amphibious caterpillar guild: new species of Hyposmocoma (Lepidoptera: Cosmopterigidae) confirm distinct aquatic invasions and complex speciation patterns

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.     

Upper Ordovician chondrichthyan‐like scales from North America

Studies of Ordovician micromeric fish scales from the Sandbian of North America have identified a number of scale‐based taxa potentially referable to the chondrichthyans and therefore can be among the stratigraphically oldest representatives of the clade described to date. Two of these, Tezakia hardingensis gen. et sp. nov. and Canyonlepis smithae gen. et sp. nov., are formally described herein. Tezakia gen. nov. scales are composed exclusively of tubular dentine and possess polyodontocomplex crowns with a characteristically large primordial odontode. Similar scale crown architecture has been reported only in the reputed chondrichthyan Altholepis composita (Lower Devonian of Podolia, Ukraine), and on these grounds, the two are united within the newly erected Altholepidiformes ordo nov. Multiple odontocomplexes are also a feature of Canyonlepis gen. nov. scale crowns; however, the latter do not demonstrate prominent primordial odontodes and are supported by a base composed of acellular bone. Additional data suggest that both taxa possess a combination of characteristics (areal crown growth, scale symmetry, linear odontocomplex architecture and absence of enamel, osteons, cancellous bone and hard‐tissue resorption) previously documented to occur only in chondrichthyan scales. This study contributes to a growing body of evidence that reveals the presence of diverse tissue types (bone, tubular and atubular dentine) and morphogenetic patterns (odontocomplex and non‐odontocomplex type of scale crown growth) in the dermal skeleton of putative Ordovician chondrichthyans.     

A new fertile Neocalamites from the Upper Permian of Russia and equisetophyte evolution

This paper deals with Neocalamites tubulatus nov. sp., an equisetophyte belonging to the Equisetaceae family. The material studied originates from the Upper Permian deposits of the northern part of European Russia. N. tubulatus nov. sp. is characterized by both sterile and fertile organs belonging to the same parent plant. It has long, flexible stems, rarely branched, with alternating nodes and prolonged ribs on the stem surface corresponding to vascular strands of the stem, and compact lateral strobili, in general aspect similar to the strobili of extant species of Equisetum. N. tubulatus nov. sp. is one of the most ancient representatives of the Equisetaceae family, which shows a distinct morphological pattern of features, among which the lateral position of strobili, characteristic of primitive equisetophytes, is most prominent in this phase of their evolution.     

An Early Cambrian stem polychaete with pygidial cirri

The oldest annelid fossils are polychaetes from the Cambrian Period. They are representatives of the annelid stem group and thus vital in any discussion of how we polarize the evolution of the crown group. Here, we describe a fossil polychaete from the Early Cambrian Sirius Passet fauna, Pygocirrus butyricampum gen. et sp. nov., with structures identified as pygidial cirri, which are recorded for the first time from Cambrian annelids. The body is slender and has biramous parapodia with chaetae organized in laterally oriented bundles. The presence of pygidial cirri is one of the characters that hitherto has defined the annelid crown group, which diversified during the Cambrian-Ordovician transition. The newly described fossil shows that this character had already developed within the total group by the Early Cambrian.     

Gas Exchange between Equisetum limosum and its Environment

Equisetum limosum grows in standing water. Its perennating rhizomesramify in the bottom mud, which is a markedly oxygen-deficientmedium. During the summer months aerial shoots are present andextend above the surface of the water to a height of about 1m. The concentration of oxygen in the internal atmosphere ofplants in the field decreases progressively from the stem tothe perennating rhizomes. There is a reverse gradient of carbondioxide concentrations. The structure of the nodal diaphragms of the aerial stem isdescribed and the progressive occlusion of the pores of thediaphragms between May and November is demonstrated. This occlusionof the diaphragms has been correlated with a reduction in thecase of gaseous diffusion along lengths of aerial stems. Oxygen is present in the rhizomes throughout the winter, despitethe fact that the dead aerial stems have broken off and thestumps have been submerged by the rise in water level, thusisolating the rhizome from atmospheric oxygen. The results are discussed in relation to the ability of theplant to grow in an oxygen-deficient environment.     

A new xeromorphic conifer from the Cretaceous of East China

Newly discovered coniferous shoots from the Cretaceous of Nanjing are attributed to the xeromorphic coniferous genus Glenrosa Watson and Fisher, which is found in China as well as in Eurasia for the first time. G. nanjingensis sp. nov. is known from shoots bearing scale-like leaves with thick epidermal cuticle and hypodermis. Stomata are confined to the abaxial surface deeply sunken in stomatal chambers which are filled with papillae. The cuticle, which has been sectioned for TEM, consists of an outer pale amorphous cuticle proper, usually with a peripheral polylamellate zone, and an inner dark cuticular layer containing reticulate fibrillae. G. nanjingensis sp. nov. bears a close resemblance to the type species G. texensis (Fontaine) Watson and Fisher from North America in gross morphology and especially in the characteristic stomatal chambers, but differs in phyllotaxis and in having the hypostomatic leaf with an obtuse apex. G. nanjingensis sp. nov. is believed to have grown near inland marshes or water bodies under hot and arid climates.     

Growth Rates of Marine Ciliates on Diverse Organisms Reveal Ecological Specializations within Morphospecies

Abstract The growth rate of 31 stocks of Euplotes, a cosmopolitan, marine, unicellular protist, on six food species representing two different food types, microalgae and bacteria, has been determined. The 31 stocks represented nine reproductively isolated groups (biological species?) based on breeding relationships. Three morphospecies, E. vannus, E. crassus, and E. minuta, each with both autogamous and cross-breeding breeding groups, were included. The mean number of fissions completed in 5 days of a breeding group growing on one of the six food species varied from zero to 17.06. There is a strong interaction between morphospecies and food type. The largest morphospecies, E. vannus, translates the nutritional content of algae into growth better than it translates that of bacteria, while the reverse is true for E. minuta, the smallest morphospecies. Autogamous breeding groups grow more rapidly on algae than on bacteria when compared to cross-breeding groups in the same morphospecies. Two breeding groups cannot grow on Escherichia coli. ANOVA of fissions completed in 5 days revealed significant main effects and interactions between many hierarchical levels of stocks and food species. These significant interactions indicate that genetically determined ecologically important information is present at all taxonomic levels—morphospecies, breeding system, breeding group, and stock. As all these levels are biologically meaningful, measuring biodiversity in the E. vannus–crassus–minuta complex solely on morphospecies will inadequately represent the ecological diversity present in the organisms and their environment. Received: 11 May 1998; Accepted: 31 July 1998     

PATTERNS OF EVOLUTION AND EXTINCTION IN THE LAST HARPETID TRILOBITES DURING THE LATE DEVONIAN (FRASNIAN)

Abstract: Late Devonian (Frasnian) harpetid trilobites have hitherto only been described from the western side of the Protethys Ocean, in what is now Europe and North Africa, as well as from Gondwana‐derived northwestern Kazakhstan (Mugodjar). However, late Frasnian strata in the Canning Basin, Western Australia, that were deposited on the eastern side of this ocean, contain a rich harpetid fauna. Described herein are two new harpetids: Eskoharpes gen. nov. and Globoharpes gen. nov., within which are placed six species: E. palanasus sp. nov., E. wandjina sp. nov., E. boltoni sp. nov., E. guthae sp. nov., G. teicherti sp. nov. and G. friendi sp. nov. The ontogenetic development of E. palanasus, E. wandjina and G. teicherti are described, including the first unequivocal harpetid protaspis. Globoharpes exhibits evidence of sexual dimorphism in the development of a pronounced preglabellar boss in some specimens. This structure is thought to have functioned as a brood pouch. Such structures have previously only been described in Cambrian and Ordovician trilobites, and never before in harpetids. It is suggested that the characteristic harpetid fringe functioned as a secondary respiratory structure. The Eskoharpes lineage shows evolutionary trends that mirror changes seen in ontogenetic development of the youngest species, suggesting the operation of peramorphic processes. This is the first record of heterochrony in harpetids and the first documented example of peramorphosis in Devonian trilobites. These harpetids demonstrate a stepped pattern of extinction during the late Frasnian, probably related to the effects of the two Kellwasser biocrises that have been well documented in European Frasnian sections. Highly vaulted species of Eskoharpes and the strongly vaulted Globoharpes became extinct at the Lower Kellwasser Event. The flatter species of Eskoharpes became extinct at the base of the Upper Kellwasser Event shortly prior to the Frasnian/Famennian boundary. The extinction of these harpetids, along with contemporaneous forms from Europe, which are also discussed herein, marks the end of the trilobite order Harpetida worldwide.     

On the Parasitic Protozoa of Liberia. I. Coccidia of Some Small Mammals.

SYNOPSIS. Four new species of Eimeria are described from small mammals in Liberia. These are: E. levinei , sp. nov. from a free-tailed bat, E. firestonei , sp. nov., and E. milleri , sp. nov., from a shrew, and E. putevelata , sp. nov., from a striped grass mouse.     

Sexual dimorphism in Australian Echiniscus (Tardigrada, Echiniscidae) with descriptions of three new species

The presence of males in species of Echiniscus has been reported only as recently as 1987 and is still considered to be rare. However, males have been found to be common in a disproportionately large number of species of this genus found in Australia. Evidence of sexual dimorphism is presented for five species (three of which are new to science), females and males of which are differentiated on the basis of distinctive gonopores. In all five species males are shorter with longer clavae. Males of Echiniscus jamesi sp. nov., Echiniscus rodnae sp. nov. and Echiniscus curiosus sp. nov. have significantly longer claws. In E. rodnae sp. nov. and E. curiosus sp. nov. males have significantly longer lateral trunk appendages and the dorsal trunk appendage combinations of males of the latter are different from those of females. The widespread distribution of bisexual species of Echiniscus in xeric habitats in Australia does not support the current theory that parthenogenetic species are favoured in such environments.