Double skeletons of silicoflagellates: Their reciprocal position and taxonomical and paleobiological values

The author addresses some problems concerning the double skeletons of silicoflagellates using examples from the Middle Miocene of Romania in conjunction with examples published in the recent literature. The main problem concerns the cause of the reciprocal position of the two individuals in double skeletons, which may occur either with the basal spines and corners of the basal rings of the two specimens aligned, or rotated from one another under different angles. Since the basal ring of the daughter skeleton must be in close proximity to that of the mother skeleton during its skeletogenesis, the main cause of rotation or non-rotation is attributed to the presence or absence of sustaining spines and their position on skeleton, namely beneath the struts or migrated onto the basal ring. A secondary cause is the position of basal spines relative to the plane of the basal ring. An approximate value of the angle of rotation of the basal rings is 180° per number of sustaining spines or struts. Species without sustaining spines, or with these spines migrated clockwise beneath the basal ring, are not rotated. In addition, species without sustaining spines are rotated when some basal spines or all are tilted under the plane of the basal ring. Cretaceous species without a basal ring are also rotated during skeletogenesis under angles depending on number of struts according to the same formula. The importance of this study is multiple: it indicates that silicoflagellates multiply asexually, it may solve some taxonomic problems, and it provides a mechanism in which new morphologies can appear suddenly, without intermediaries. From paleobiological point of view, this study provides an explanation of why in fossil materials, the position of the daughter skeleton with respect to the mother one was in many cases different from that of living species. A short taxonomic appendix is included with a brief discussion of the taxonomic problems of some genera and species mentioned in this article.     

On the status of the Permian radiolarian genus Multisphaera Nazarov and Afanasieva, 2000

Based on the detailed morphological study of the type species of the genus Multisphaera Nazarov and Afanasieva, the author emends the status and diagnosis of this genus and of the subfamily Multisphaerinae Nazarov and Afanasieva. He found that the initial spicule of the type species is not multi-rayed, as initially thought, but a tetrahedral spicule. Accordingly, the genus is assigned to the former tribe Tetrentactiniini Kozur and Mostler that is herein raised to the family rank and comprises all Upper Devonian to lower Permian genera with a tetrahedral initial spicule. Consequently, the subfamily Multisphaerinae is considered a junior synonym of the family Tetrentactiniidae. To better solve the taxonomic problems of this family the author compares the morphological diversity of its members with the morphological diversity of the lower Tithonian (uppermost Jurassic) tetrahedral spicule-bearing entactinarian Radiolaria occurring in the Solnhofen area, southern Germany. Although these genera have the same type of spicule as the Paleozoic ones, they seem to belong to a new family because between the lower Tithonian and the lower Permian genera there is a long time interval of about 120 Ma in which no radiolarians with a tetrahedral initial spicule have been recorded so far. This comparison shows once more the conservative character of the initial spicule and the wide morphological diversity of the extraspicular shell.     

Bryophytes of St Helena,South Atlantic Ocean. 8. Lepidopilidium crispifolium,sp. nov. (Hookeriales,Pilotrichaceae)

Abstract

A new species of Lepidopilidium (Pilotrichaceae, Hookeriales), L. crispifolium, sp. nov. from St Helena, South Atlantic Ocean is described and illustrated.     

八角属植物分类

根据对18个国家和地区121个标本馆收藏的万余份八角属植物标本研究,结合在国内8个省区野外调查、采集、引种和对生长发育与物侯的观察,本文对世界性八角属植物做了分类学修订。根据花蕾和花被片形态特征的变异,将八角属分为2组:八角组-含9种1亚种,其花蕾卵球形,花被片长圆形、椭圆形、披针形至狭舌状,扁平;八角茴香组-含25种2亚种1变种,其花蕾球形,花被片宽卵形至圆形,下凹。将凹脉组作为八角组的新异名,圆被亚属作为八角茴香组的新异名;指定了红茴香和柬埔寨八角的后选模式。本文还分析了八角属植物的分类学性状,作出有分类检索表,提供有各种植物的地理分布资料,列举出查阅的主要标本,并对各分类单元均作了分类学注释。     

八角属植物分类

根据对18 个国家和地区121 个标本馆收藏的万余份八角属植物标本研究, 结合在国内8 个省区野外调查、采集、引种和对生长发育与物侯的观察, 本文对世界性八角属植物做了分类学修订。根据花蕾和花被片形态特征的变异, 将八角属分为2 组:八角组-含9 种1 亚种, 其花蕾卵球形, 花被片长圆形、椭圆形、披针形至狭舌状, 扁平;八角茴香组-含25 种2 亚种1 变种, 其花蕾球形, 花被片宽卵形至圆形, 下凹。将凹脉组作为八角组的新异名, 圆被亚属作为八角茴香组的新异名;指定了红茴香和柬埔寨八角的后选模式。本文还分析了八角属植物的分类学性状, 作出有分类检索表, 提供有各种植物的地理分布资料, 列举出查阅的主要标本, 并对各分类单元均作了分类学注释。     

Paraimene tuberculata,a new genus and species of Isopoda (Sphaermomatidae) from Karachi,Pakistan

A new genus,Paraimene is established for a new Isopod species from the intertidal zone of Karachi Coast (Pakistan).Paraimene tuberculata sp. nov. is described and illustrated together with notes on the habitat of the species.     

Systematics of tarsiers and lorises

It seems probable that there are more species (in the sense of sharply diagnosable entities) than hitherto recognized among small Asian primates, and contrasting to some degree with larger-sized taxa. This presumably relates to their lesser vagility and consequent reduced potential for gene-flow. Even where some gene-flow can be demonstrated, as betweenNycticebus coucang andN. bengalensis, this appears to be very limited and does not affect the essential homogeneity and diagnosability of the two taxa. The biogeographic implications of the taxonomic findings of this study are noteworthy. They confirm the distinctness of Sulawesi in contrast to a Sundaland/southern Philippines link (Tarsius); the separation of the Indochinese and Sundaic faunal subregions (Nycticebus); and the uniqueness of the Sri Lankan “wet zone” (Loris). Much more work needs to be done on all three genera, but their great taxonomic interest, indicating much greater complexity than previously assumed, is apparent.     

Aotus vociferans ×Aotus nancymai: Sympatry without chromosomal hybridation

In a study relating geographic distribution ofAotus populations with karyotype and coat pattern,Hershkovitz (1983) suggested that this genus comprises nine species.A. vociferans (2n=46) is distributed along the left bank of the Maranon river, andA. nancymai (2n=54) along the right bank of the same river. In the present study we analyzed the karyotypes of 11A. vociferans and 11A. nancymai specimens using G- and C-banding and NOR-staining. Of these animals, fiveA. vociferans were sympatric with fiveA. nancymai in Isla Aramaza, Colombia; oneA. vociferans was sympatric with threeA. nancymai in Yahuma, Peru; oneA. vociferans was sympatric with threeA. nancymai in Terezinha I, Brazil. No signs of hybridation between the taxa was observed at any time, with allA. vociferans having 2n=46 and allA. nancymai 2n=54, as previously reported in the literature. These data suggest thatA. vociferans andA. nancymai should indeed be distinct species.     

Phagnalon rechingeri (Inuleae,Asteraceae), a new species from Iran

Phagnalon rechingeri spec. nova from S Baluchestan (Iran) is described as a species new to science and illustrated; its relationships to other species of the genus, in particular to thePh. woodii group from S Arabia, are discussed.Dedicated to Hofrat Univ.-Prof. DrK. H. Rechinger on the occasion of his 80th birthday.     

Taxonomic Notes on Four Species of Panagrellus Thorne (Nematoda: Cephalobidae)

Four populations of Panagrellus redivivus (Linnaeus, 1767) Goodey, 1945, and syntypes of P. dubius Sanwal, 1960, P. redivivoides (Goodey, 1943) Goodey, 1945, P. pycnus Thorne, 1938, P. zymosiphilus (Brunold, 1950) Brunold, 1954, and P. leucocephalus Steiner, 1936 were examined. Additional information on the morphology of spicules and stoma is presented. P. zymosiphilus is synonymized with P. redivivoides and Rühm''s synonymization of P. silusiae and P. leucocephalus with P. redivivus is supported. Lectolypes for P. pycnus and P. redivivoides are designated.