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1.
A new family of the order Rhabdomesida, Medvedkellidae fam. nov., is described. This family consists of a new genus, Medvedkella gen. nov., comprising three species transferred from the genus Rhombopora Meek, 1872: the type species M. riasanensis (Schulga-Nesterenko, 1955), M. diaphragmata (Schulga-Nesterenko, 1955), and M. mariae (Dunaeva, 1961). The morphogenesis of the first two species is studied. For the first time axial zooecia are revealed in the suborder Golgdfussitrypina, which existed in parallel with the suborder Rhabdomesina of the order Rhabdomesida. A hypothesis that the new family evolved from the subfamily Nicklesoporinae Gorjunova, 1985 of the family Goldfussitrypidae, 1985 is proposed. Some questions of the ecological adaptation of these bryozoans in the Late Carboniferous marine basin of the East European Platform are discussed.  相似文献   

2.
The calcareous opercula ofInversaria tubiporacea (Goldfuss 1826) from the Dutch Maastrichtian Chalk-tuff are described and figured by Stereoscan photographs. The genusInversaria v.Hagenow 1851, as demonstrated byVoigt &Williams (1973), belongs to the Cheilostomata and not, as maintained hitherto, to the Cyclostomata. The discovery of true opercula in situ inInversaria also serves as important evidence for the cheilostomatous character of that genus. In comparison with the opercula of Recent Cheilostomes, these opercula, the first to be found in fossil species, are highly calcified and provided with strange outgrowths the like of which have never been observed in Recent species. On their frontal surface exists a conical process which is directed distally and is often curved. It starts from the hollow central disc of the operculum. On the reverse (internal) surface two symmetrical pairs of branching spines (sclerites) arise vertically from a horizontal cross-bar; the external pair is more prominent with antler-like apophyses, projecting like two corner pillars into the lumen of the zooecia. The median pair is lower and often found to be coalesced into a knobbed or thorny clew. The zoarium ofInversaria tubiporacea consists of a vertical central axis surrounded by regular concentric layers of subsequently formed zooecia with budded only by proliferation after the degeneration of the foregoing older ones (frontal budding) and not by simple encrustation of autonomous outer layers of new zooecia enveloping the periphery of the zoarium. The zooecial tubes are observed to continue directly through all these outer layers, but in fast consist of a series of distinct zooecia following each other by budding and subsequent degeneration. This may be demonstrated by the fact that in the same tube passing through all these layers the opercula of several different generations of polypides are represented. Therefore, it must be concluded that, in similarly constructed zoaria of cyclostomatous and trepostomatous Bryozoa, the zooecial tubes which apparently were secreted only by one polypide must have been built up by numerous successive generations of zooids, each budded every time the degeneration of a parental zooid occured.  相似文献   

3.
Topotype material of Pustulopora pustulosa (Goldfuss), the type species of Pustulopora Blainville, is investigated and its structure described. It has a distinctive budding pattern in which autozooecia are formed from an axial bundle of zooecia. The gonozooecium is of ' Mecynoecia '- shape.  相似文献   

4.
Morphologically complex bryozoans from the Upper Devonian and Lower Carboniferous of Eurasia that some research workers include in the order Rhabdomesida and others place in the order Trepostomata are studied. The axial zooecium is demonstrated to be of zooidal nature. A new family, Coelotubuliporidae fam. nov., is established and its position in the order Trepostomata is substantiated. It includes two genera (one new), 11 species (1 new), and four subspecies. Diagnoses of a new family, Coelotubuliporidae, the genus Coelotubulipora Yang, Hu et Xia, 1988, and a new genus, Dunaevella Gorjunova gen. nov., are presented. The following species are described: Coelotubulipora irinae Gorjunova, sp. nov., Dunaevella shishovae (Schulga-Nesterenko, 1955), and D. peristomata (Schulga-Nesterenko, 1955). The emergence of axial zooecia in representatives of the order Trepostomata is considered as one of the evolutionary ways of bryozoans due to morphological parallelisms. It is shown that data presented on the stratigraphic range and paleogeography of the family Coelotubuliporidae are of great significance for solving the problems of biostratigraphy and correlation of deposits of the Upper Devonian and Lower Carboniferous of Eurasia.  相似文献   

5.
Three new species are described in the cheilostomate bryozoan genus Schizoporella Hincks, 1877. British records of Scliizoporella dunkeri Reuss are shown to represent two previously unnamed species. Scliizoporella dunkeri is the senior synonym of the Adriatic species Schizoporella longirostris Hincks. Material of S. longirostris from British localities is referred in part to S. dunkeri and in part to a previously unnamed species.  相似文献   

6.
《Palaeoworld》2019,28(3):289-294
Enlarged, ‘compound zooecia’ are described for the first time in a trepostome bryozoan. Several of these zooecia are visible in tangential sections of Eostenopora guizhouensis (Hu) from the Devonian (Eifelian) Houershan Formation of Houershan, Dushan, southern Guizhou, China. They are broad and occupy the space of two or occasionally three or four normal autozooecia. Some have bridging walls extending partway across the enlarged zooecial chamber. Without serial sectioning, the origin of compound zooecia in E. guizhouensis is debatable. However, the existence of irregular gaps in some zooecial walls leads to the hypothesis that compound zooecia originated from the loss by resorption of the skeletal walls between two normal autozooecia. The bridging walls are interpreted as a response by the bryozoan to restore the integrity of the constituent zooecia. By analogy with the ‘Doppelgänger’ zooids of some modern cheilostome bryozoans, compound zooecia of E. guizhouensis may have housed the lophophores of more than one zooid.  相似文献   

7.
Cilia-generated flow in the absence of ambient current is directed from frontal to reverse sides of branches in Bugula turrita, B. turbinata, B. neritina , and B. stolonifera , whether axes of feeding lophophores are perpendicular to the basal plane of branches or are tilted toward distal ends of branches. Ambient current less than 5 cm per second interacts with cilia-generated flow, but ambient flow of 15 cm per second destroys self-generated colonial flow and severely hampers feeding. Polypides are located in the more distal, younger portions of colonies, in species with and without polypide recycling, whereas zooids in the more proximal, older portions are senesced. Presence of feeding polypides in distal but not in proximal portions of the larger spiralled colonies of B. turrita and B. turbinata results in downward, slightly radially directed flow through the colony. The colonial flow passes directly from one whorl to the next-proximal so that water exits from low around the colony perimeter, and a proximally expanding conical stagnant zone occupies the interior of the colony. A substantial percentage of zooecia in distal whorls of well-preserved Archimedes is filled by sediment and inferred to have been occupied by actively feeding polypides. whereas spar-filled zooecia capped by terminal diaphragms were apparently senesced during the latter part of a colony's existence. The capped zooecia constitute an increasing percentage of the total in more proximal whorls. Generally similar colony form and inferred similarity in distribution of current-generating polypides in spiralled colonies of Bugula and in Archimedes suggest that colony-generated flow in Archimedes was similar to that in Bugula , passing downward and then outward, and only through the distal whorls of the colonies.  相似文献   

8.
Septocea septifera n.g. n.sp. (Family Semiceidae Buge) is a very strange free-walled cyclostome bryozoan species of Maastrichtian age with regard to its apertural morphogenesis. The zoarium is erect, eschariform, without heteromorphs, the aperturae lack ringlinke peristoms and are subdivided by vertical septa. The septa are recognized as extern walls of axially budded immature zooecia in the interior of the living chamber. The oval to triangular apertura is subdivided by the septa into one larger and one or two smaller openings. The evidence that axial intrazooecial budding also exists in other, not closely related taxa, proves that these structures are convergent. Their morphogenesis, systematic value and the taxonomic status of the Family Semiceidae are discussed.  相似文献   

9.
番荔枝科的地理分布   总被引:4,自引:0,他引:4  
番荔枝科的地理分布陈伟球(中国科学院华南植物研究所,广州510650)关键词番荔枝科;地理分布THEGEOGRAPHICALDISTRIBUTIONOFTHEANNONACEAE¥ChenWeichiu(SouthChinaInstituteofBo...  相似文献   

10.
The global geographic ranges occupied by 197 species of cheilostomate Bryozoa found in British waters were obtained by a literature survey. Morphological grade, larval mode, environmental tolerance, species abundance and the ability to raft and to foul shipping were all investigated as traits potentially able to affect the geographic ranges of these bryozoan species. When considered independently all variables except larval mode had a significant correlation with the geographic range occupied by a species. However, when controlling for the potentially confounding effects of the other covariates, only the ability to foul or raft and species abundance had a significant effect on median geographic range and only fouling and abundance had a significant effect over global ranges. The strength of the association between fouling ability and range suggests that transport upon the hulls of ships is a very important dispersal mechanism for bryozoans, as it is thought to be also for various other marine taxa. Potential long-term (evolutionary) consequences of increased ranges brought about by anthropogenic mechanisms are discussed.  相似文献   

11.
Nine species of the cheilostomate bryozoan genus Parasmittina Osburn, 1952, are described. Neotype specimens are selected for P. parsevalii (Audouin) and P. raigii (Audouin). P. hastingsae Soule and Soule, P. agathae sp. nov., P. parsloeparsloei sp. nov., P. pectinata sp. nov. and P. solenosmilioides sp. nov. are described from Australian localities. P. fistulata (Harmer) is redescribed and P. decorata Soule and Soule is placed in the synonymy of P. delicatula (Busk).  相似文献   

12.
13.
本文报道中国假尾孢属的24个种,其中有2个新种:杨桐假尾孢(Pseudocercospora adinandrae Guo&Liu),钟萼假尾孢(Pseudocercospora bretschneiderae Liu&Guo),10个新组合,1个新名称:木豆假尾孢(Pseudoeercospora cajani-flavi Guo&Liu)和11个中国新记录。文中对2个新种提供了拉丁文简介、描述及图。所研究的标本全部保存在中国科学院微生物研究所真菌标本室(HMAS)。  相似文献   

14.
15.
本文报道了单囊壳属Sphaerotheca的一新种:乌蔹莓单囊壳Sphaerotheca cayratiae Z.Q.Yuan et A.Q.Wang sp.nov.。新种寄生于葡萄科Vitaceae植物角花乌蔹莓Cayratia corniculata(Benth.)Gagnep上,为单囊壳属的寄主科世界新记录。文中对该新种的形态特征作了拉丁文和中文描述,并讨论了新种与本属内相似种的区别。模式标本存于新疆八一农学院植保系真菌标本室。  相似文献   

16.
棕榈科植物的地理分布   总被引:9,自引:0,他引:9  
棕榈科是一个泛热带分布的科,共有198属,约2670种,下分6亚科,14族。贝叶棕族是最原始的族,低地榈族则最进化。本科植物在世界上的分布可划分为13个区,其中以印度-马来西区和新热带区的属、种最多。中国只有16属和85种,没有特有属。这些种大部分属热带亚洲分布,与热带亚洲植物区系关系非常密切。关于棕榈科起源地问题,有西冈瓦纳起源和劳亚起源之说。根据化石记录和形态特征的分析,棕榈科很可能于早白垩纪  相似文献   

17.
Stomach contents of Kalinga ornata and Plocamopherus tilesii (Nudibranchia: Doridacea: Polyceridae) were investigated using a light microscope to reveal their natural diets. Ossicles of ophiuroids were found in the stomachs of four out of 29 specimens of K. ornata. In contrast, both zooecia of Bryozoa and ossicles of ophiuroids were found in the stomachs of P. tilesii specimens. This is only the second record of a nudibranch species feeding on ophiuroids.  相似文献   

18.
樟科植物中脂肪酸成分的分布   总被引:1,自引:0,他引:1  
本文报道了樟科11个属49种种子油和‘种果肉油的脂肪酸成分。其中樟族和木姜子族的各属种(滇新樟除外)种子油脂肪酸成分以 C_(10)、C_(12)和 C_(14)饱和或烯酸为主。而厚壳桂属、润楠和楠属种子油脂肪酸成分主要为棕榈酸、油酸和亚油酸。山苍子、天目木姜子、大果山胡椒、山橙、红脉钓樟、鸭公树和锈叶新木姜子种子油中的 C_(10)、C_(12)和 C_(14)烯酸经分离鉴定均是顺式Δ~4烯酸。  相似文献   

19.
C. J. O. Harrison 《Ibis》1963,105(2):145-155
The plumage of the Estrildidae was examined in order to determine the incidence and origin of the spotted patterns.
In the Australian grassfinches a series of feathers showing the derivation of spotted patterns from transverse barring was found in two species. In most species such patterns consisted of single broad spots, but in two species paired spots were present.
The mannikins show three types of spotted pattern. One is derived from transverse barring, another from a rachial streak, and the third from a combination of both bars and streaks. The last one is not a true spotted pattern, the effect being due to overlapping feathers.
The waxbills show spotted patterns derived from transverse barring, the development of which exactly parallels that shown by the grassfinches, but differs in that almost all patterns show paired spots.
The spotted patterns appear to have been derived from a basic barred pattern in most cases, and to represent an increasing complexity of pattern rather than a gradual loss.
It is considered that similar patterns in widely separated species are due to parallel evolution of patterns and not to phylogenetically close relationship.
Where various species show different successive stages in the evolution of a pattern, this does not indicate that one is ancestral to another. Since the species concerned have a common family relationship, the potential for such a pattern may be present throughout the family.
Since the patterns have a function in specific recognition, it is suggested that similar patterns are likely to recur in widely separated localities and that the patterns of sympatric species are likely to differ. If similar patterns are present in one area they will probably indicate close relationship.
The inference of this in relation to plumage pattern problems in some other orders is briefly discussed.  相似文献   

20.
长江安庆段仔稚鱼群落特征调查研究   总被引:1,自引:0,他引:1  
安庆江段是长江下游重要渔业资源水域之一, 为了解该江段仔稚鱼群落特征及与环境因子的关系, 于2016年4月17日至8月15日对安庆江段仔稚鱼进行了逐日调查。结果显示: 研究共采集仔稚鱼个体92160尾, 鉴定90457尾, 隶属于7目11科49种, 其中鲤科(Cyprinidae)种类数居第一, 32种, 尾数占比为90.16%; 鰕虎鱼科(Gobiidae)居第二, 3种, 尾数占比为5.71%。在生态类型及产卵方式上, 淡水定居性鱼类和产漂流性卵鱼类数量占比最大, 分别为87.57%和88.30%。贝氏?(Hemiculter bleekeri)是该江段第一优势种, 数量占比44.53%, 其余优势种为?(Hemiculter leucisculus, 占比14.21%)、银鲴(Xenocypris argentea, 占比8.11%)、子陵吻鰕虎(Rhinogobius giurinus, 占比5.60%)、飘鱼(Pseudolaubuca sinensis, 占比4.75%)、似鳊(Pseudobrama simoni, 占比4.13%)、寡鳞飘鱼(Pseudolaubuca engraulis, 占比4.50%)、鳊(Parabramis pekinensis, 占比2.63%)、刀鲚(Coilia nasus, 占比1.89%)、鲢(Hypophthalmichthys molitrix, 占比1.57%)。仔稚鱼丰度出现4次明显的高峰时期, 第一次在5月1日, 后面三次集中出现在6月中下旬, 分别为1127.00、1608.44、1568.35 和1202.94 ind./100 m3。通过冗余分析(RDA)表明, 影响安庆江段仔稚鱼丰度的主要环境因子为水流量、水位、透明度(P<0.05), 大多数仔稚鱼丰度与水流量、水位呈现负相关, 与透明度呈现正相关, 可能与该年份过高的水流量、水位有关。研究表明, 安庆江段的仔稚鱼种类较丰富, 但主要以小型鱼类为主, 且经济性仔稚鱼类占比小。研究初步探明了安庆江段的仔稚鱼资源状况, 其结果为安庆鱼类早期资源进一步研究提供基础资料, 同时也为渔业资源保护策略制定提供科学依据。  相似文献   

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