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1.
Goryunovia hemiseptata n.gen. n.sp. is an unusual Lower Ordovician cyclostome bryozoan, represented by a single colony from the Middle Volkhov Stage (Arenig) of the Leningrad Oblast. The encrusting uniserial colony consists of large, slender zooids, many with closely-spaced partial diaphragms (hemisepta), and has a distinctive trichotomous branching pattern. Skeletal organization is of the sagenellid grade: calcified interior walls appear to be present, and the exterior frontal walls lack pseudopores. As details of microstructure and early astogeny are unknown, it is difficult to interpret the phylogenetic relationships ofGoryunovia until further material is forthcoming. However, there is some resemblance with the enigmatic hederellids, which appear in the Upper Silurian and possibly range into the Triassic.  相似文献   

2.
The cyclostome Bryozoan speciesPustulopora verrucosa, described by Roemer 1840, is combined with two other congeneric species within the new genusPachyteichopora (type-speciesP. verrucosa [Roemer]). This new genus characterized by its extremely highly calcified external walls of the erect massive cylindrical and dichotomously branched zoaria possessing maculae. The similarity of its gonozooid to that ofLeiosoecia counts for its provisional attribution to the Fam. Leiosoeciidae Canu & Bassler (1920).P. bugei n. g. n. sp. from the French Coniacian andP. punctata n. g. n. sp. from the Swedish Campanian are described.  相似文献   

3.
Microporella speciosa sp. nov. is described from Alaska, USA. The new species is characterized by the following combination of features: 1) semicircular orifice with slightly curved and faintly denticu-late proximal edge having a straight, shallow groove, 2) two distal oral spines, 3) laterally directed avicularian rostrum with a broad, channeled tip, 4) open frontal pores, and 5) completely calcified basal walls. Opercula, avicularian mandibles, the ancestrula, and early ontogeny are also described.  相似文献   

4.
Amoebae of the order Vannellida (Amoebozoa, Discosea) have a fairly recognizable spatulate, fan-shaped or semi-circular outlines and a wide area of frontal hyaloplasm. They can be easily distinguished from the other groups of lobose amoebae even by light microscopy. The dorsal side of these amoebae is usually smooth and rarely bears ridges or folds, which are never numerous or regular. We have isolated an unusual species of vannellid amoebae, called Vannella primoblina n. sp. from a terrestrial substrate. It has well-developed dorsal relief consisting of regularly appearing folds and ridges. This amoeba superficially resembles members of the genus Thecamoeba. However, molecular analysis showed that this strain belongs to the genus Vannella. This finding indicates that dorsal folds may also be a characteristic of some species of vannellid amoebae and probably are a functional detail of the cell morphology rather than an apomorphy of Thecamoebida lineage. Overall outlines of the cell and the presence of the expanded frontal hyaline area remains the most reliable characters used to differentiate vannellid amoebae from other gymnamoebae lineages.  相似文献   

5.
Lars Siln 《Acta zoologica》1977,58(4):227-244
The “rhizoidsrdquo; surrounding the base of the erect “colony” emanating from the ancestrula in the Crisiidae, especially the simple species Crisidia cornuta (L.), are a regular adnate system of autozooids. Each autozooid is composed of a proximal adnate part and a distal peristome (in some species kenozooids are possibly intercalated). The autozooid peristomes support erect branches identical in budding and structure with the branch emanating from the erect peristome of the ancestrula. Thus, the complete crisiid colony consists of an adnate system of ancestrula and autozooids, which form erect branches from their peristomes. The adnate zooid system is comparable in autozooid morphology and budding pattern with simple uniserial stomatoporids. The tentative hypothesis is proposed that the crisiid group has developed from primitive stomatoporids; the adnate zooid system of the stomatoporids apparently evolved peristomial budding to produce the erect colony branches characteristic of crisiids.  相似文献   

6.
Elephantotus, a new genus of Tabanidae from the Amazon coast, Brazil, is described based on a new species E. tracuateuensis. Five females were collected in Pará State, and a male in Maranhão State. Arguments are presented for separating the new genus from Dasybasis, as well as the possibility of its occurrence being related to the nesting sites of coastal birds. The new species is characterized by its large size (x = 2.15 cm, n = 5 females), glabrous eyes, reddish-brown tegument, light brown frontal callus not touching the edges of the eyes, extending up to the vertex that has traces of ocelli, basal plate of the antennal flagellum with obtuse angle, without a tooth or spine, wings hyaline, with brown basal cells, without appendix in the fork of vein R4+5, and genital furca wide with extended flaps.  相似文献   

7.
This paper investigates the morphology, morphogenesis and SSU rRNA gene-based phylogeny of Apoholosticha sinica n. g., n. sp., isolated from mangrove wetland in Shenzhen, southern China. The new genus Apoholosticha is characterized by its bipartite adoral zone, clearly differentiated frontal cirri arranged in a bicorona, midventral complex composed of midventral pairs only, one marginal cirral row on each side, presence of frontoterminal and transverse cirri, and the lack of a buccal cirrus and caudal cirri. The type species, Apoholosticha sinica n. sp. is diagnosed by the elongated body shape and two kinds of cortical granules. Its main morphogenetic features are similar to that of Pseudokeronopsis except for (1) no buccal cirrus is formed and (2) its macronuclear nodules fuse into a single mass during cell division. Phylogenetic analyses for the new taxon indicate that Apoholosticha n. g. is most closely related to Nothoholosticha and Heterokeronopsis, and falls into the family Pseudokeronopsidae within the core Urostylida clade. In addition, a species that had been misidentified in previous literature is here recognized and assigned to the new genus as Apoholosticha sepetibensis (Wanick and Silva-Neto, 2004) n. comb. (basionym: Pseudokeronopsis sepetibensis Wanick and Silva-Neto, 2004).  相似文献   

8.
9.
Explorations in Brazil to find parasites of the red imported fire ant, Solenopsis invicta Buren, have uncovered a new species of the Tetradonematidae, Tetradonema solenopsis n. sp. The nematode parasite was fatal to about 25% of the colony. The female nematodes are large and sausage shaped and the males are small and difficult to find, which is typical of the genus. The ant is a new host record for tetradonematids.  相似文献   

10.
Pellamaoershanensis Song & Li, sp. n., collected from a colony of Lasius (Dendrolasius) spathepus in Maoershan Natural Reserve, Guangxi, is diagnosed, described and illustrated. The discovery represents the first record of the genus in South China.  相似文献   

11.
Alloencotyllabe caranxi n. g., n. sp. is found in groups of 9–15 specimens attached close together to the lower pharyngeal plate of Caranx sp. It is characterized by having an elongate body, a prohaptor with large spines, an armed penis which lies in a pouch and a vaginal pouch guarded by two sets of glands. Encotyllabe kuwaitensis n. sp. is attached individually to the lower pharyngeal plate of Caranx sp. It is characterized by having an elongate body and tandem testes. E. spari is reported from the lower pharyngeal tooth plate of Plectorhynchus cinctus, P. pictus and P. schotaf. All fish hosts were caught in Kuwaiti waters in the Arabian Gulf. The subfamily Encotyllabinae is reviewed and the genus Neoencotyllabe is regarded as a genus inquirendum. The new genus is attached to the subfamily Encotyllabinae.  相似文献   

12.
13.
Molecular phylogenetic analysis of an extensive collection of monozoic tapeworms of the genus Paracaryophyllaeus Kulakovskaya, 1961 (Cestoda: Caryophyllidea), parasites of loaches (Cypriniformes: Cobitidae) in Eurasia, has revealed cryptic species diversity within this long-time monotypic genus, especially in the Paracaryophyllaeus gotoi (Motomura, 1927) species complex [syn. Paracaryophyllaeus dubininorum (Kulakovskaya, 1961); type species]. Three independent, well-supported clades were discovered on the basis of molecular data: (i) specimens from Misgurnus anguillicaudatus and Cobitis lutheri from China, Russian Far East and Japan — called herein P. cf. gotoi 1, which may be conspecific with P. gotoi (Motomura, 1927), although in the absence of sequence data for P. gotoi from its type locality (basin of the River Kumkan in Korea), no certain inferences about their identity can currently be made; (ii) specimens from M. anguillicaudatus from China and Japan — P. cf. gotoi 2, which are morphologically indistinguishable from those of P. cf. gotoi 1; and (iii) morphologically distinct tapeworms from the endemic loach Cobitis bilseli from southwestern Turkey (Beyşehir Lake), which are described herein as a new species. Paracaryophyllaeus vladkae Scholz, Oros and Aydoğdu n. sp. differs from the remaining species of the genus in the following characteristics: the testes begin anterior to the first vitelline follicles (versus posterior), the body is short and robust (versus more elongate and slender), and the scolex is wide, rounded or apically tapered (versus claviform to truncate). Species composition of the genus, host specificity of species and geographical distribution are briefly discussed.  相似文献   

14.
Communication organs (septulae) of cheilostome Bryozoa are more complex than perviously believed. Annuli, present only in lateral septulae, are thickenings of the intercalary cuticle. Each communication pore is filled with a ring-like “pore cincture,” through which project a pair of “special cells.” Septulae of all species examined (10 species from 6 families) can be considered modifications of the same structure, varying only in degree of calcification and number of communication pores. External walls, including basal and lateral walls, are best defined as reinforcements of the ectocyst, which is derived by intussusception from the primary cuticle of the ancestrula. The lateral ectocyst must be considered a double layer formed by invagination of the distal ectocyst. Internal walls are developed by apposition from inner parts of the ectocyst; they include pore plates and transverse walls. External walls are laid down first. Lenticular masses develop unilaterally on the uncalcified lateral ectocyst; the pore plate develops by apposition from the interior part of the ectocyst. Depending on the species, the pore plate may or may not be calcified at the time of its formation. Communication pores are formed when the developing pore plate abuts against embryonic special cells. The septular ectocyst never calcifies; it breaks down when the pore plate is complete. Some ascophorans undergo “reparative budding,” in which new zoids are formed within dead zoecia. Hollow, ectocyst-covered buds lined with blastemic epithelia are produced from septulae of live zoids; adjacent buds may fuse. These findings are consistent with the view that lateral septulae are aborted zoids and that pore plates represent transverse walls.  相似文献   

15.
A new boring ctenostome bryozoan without calcareous skeleton, Orbignyopora opulenta sp. nov. (Vesiculariida, Eurystomata), is described from deposits of the Middle Callovian of the Moscow Region. A pioneering micro-ct examination of a colony of this species reveals its diagnostic features hidden in the shell substratum: shape, size, and distinctive features in the budding of zooids and stolons, and also tubular processes (tubulets) developed on the frontal surface of autozooids. The diagnosis of the genus Orbignyopora is added by dimorphism of autozooids (A-zooids and B-zooids) and spindly kenozooids.  相似文献   

16.
The Ilerdian is a well-established Tethyan marine stage, which corresponds to an important phase in the evolution of larger foraminifera not represented in the type-area of the classical Northwest-European stages. This biostratigraphic restudy of its parastratotype in the Campo Section (northeastern Spain) based on planktic foraminifera, calcareous nannofossils, dinoflagellate cysts and the distribution of the stable isotopes ∂13C and ∂18O is an attempt to correlate the Paleocene/Eocene boundary based on a characteristic carbon isotope excursion (CIE) marking the onset of the Initial Eocene Thermal Maximum (IETM) and the Ilerdian stage. The base of this ∂13C excursion has been chosen as the criterion for the recent proposal of the Global Stratotype Section and Point (GSSP) of the base of the Eocene (= base of the Ypresian) in the Dababiya Section (Egypt) to which an age of 54.9 Ma has been attributed. This level is also characterized by a marked extinction among the deep-water benthic foraminifera (Benthic Foraminifera Extinction Event, BFEE), a flood of representatives of the planktic foraminiferal genus Acarinina and the acme of dinoflagellate cysts of the genus Apectodinium. In the Campo Section, detailed biozonations (planktic foraminifera, calcareous nannofossils, dinoflagellate cysts) are recognized in the Lower and Middle Ilerdian. The correlation with the Ypresian stratotype is based on dinoflagellate cysts and calcareous nannofossils. The base of the Ilerdian is poor in planktic microfossils and its precise correlation with the redefined Paleocene/Eocene boundary remains uncertain.  相似文献   

17.
18.
Semitubina sakoi n. sp. from the late Silurian of Japan represents the second species of this genus and also the first record of a Silurian gastropod in Japan. The gastropod shells occur in a thin mudstone bed and were found to be encrusted exclusively by corallites of ? Favosites sp. These corallites reveal that encrustation proceeded as the gastropod shells grew. The ecological relationship between the two organisms is considered to be symbiotic. This mode of life allowed the coral to live on a muddy substrate because clear sea water passed over the colony as the gastropod moved along. The gastropod benefited from this relationship by being protected from shell-boring or shell-crushing predators by the encrusting corallite. In Semitubina sakoi the body whorl is separated from the penultimate one by a considerable gap in a later growth stage and S. sakoi has been cited as one of the uncoiled gastropods. The uncoiling of this gastropod results primarily from rapidly increasing whorl translation rate in the latest growth stage. Taking the symbiotic relationship with ? Favosites sp. into consideration, a deposit feeding or benthic scavenging mode of life is suggested for this gastropod.  相似文献   

19.
A new subfamily, Pararotylenchinae, (Hoplolaimidae) is described. It includes a single genus, Pararotylenchus n. gen., six new species, attd two new combinations, Pararotylenchus (syn. Tylenchorhynchus) brevicaudatus (Hopper, 1959) n. comb. and Pararotylenchus (syn. Rotylenchus) pint (Mamiya, 1968) n. comb. Pararotylenchinae is similar to certain other Hoplolaimidae, such as Rotylenchinae, with respect to most characters including the short tail, the position of the phasmids near the anus, and the relatively great distance of the dorsal gland orifice from the base of the stylet knobs. The lip region, as observed with the scanning electron microscope, conforms to the basic pattern for Hoplolaimidae. The labial disc is round with slit-like amphidial openings at the lateral sides of the periphery of the disc. The distinctive anterior-most lip annule is segmented into six sectors. Unlike other Hoplolaimidae, however, the esophageal glands of Pararotylenchinae form a basal bulb similar to that of Tylenchorhynchidae; other characters do not resemble Tylencborhynchidae. Specimens of Pararotylenchus have been recovered only from cool regions at high elevations and Pacific coastal areas in the Western United States, Japan, and Korea.  相似文献   

20.
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