990 resultados para Arachnida, Fossil


Relevância:

60.00% 60.00%

Publicador:

Relevância:

30.00% 30.00%

Publicador:

Resumo:

I. Paleozoic fossils.--II. Mesozoic fossils.--III. Cenozoic fossils.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We present new data on litter size and date of birth (month) for 21 South American scorpions species. We provide data for one katoikogenic species, the liochelid Opisthacanthus cayaporum Vellard, 1932 (offspring = 3; birth month: Jan); and for several apoikogenic species, such as the bothriurids Bothriurus araguayae Vellard, 1934 (53; Sep), B. rochensis San Martín, 1965 (22-28; Jan, Aug); the buthids Ananteris balzanii Thorell, 1891 (10-34; Jan-Mar), Physoctonus debilis (Koch, 1840) (2; Sep), Rhopalurus amazonicus Lourenço, 1986 (19; Nov), R. lacrau Lourenço & Pinto-da-Rocha, 1997 (30; Dec), R. laticauda Thorell, 1876 (41; Nov), R. rochai Borelli, 1910 (11-47; Dec-Jan, Mar-Apr), Tityus bahiensis (Perty, 1833) (4-23; Oct-Mar), T. clathratus Koch, 1844 (8-18; Nov-Jan), T. costatus (Karsch, 1879) (21-25; Jan, Apr), T. kuryi Lourenço, 1997 (4-16; Mar), T. mattogrossensis Borelli, 1901(8-9; May), T. obscurus (Gervais, 1843) (16-31; Jan-Feb, May, Jul), T. serrulatus Lutz & Mello, 1922 (8-36; Dec, Feb-Apr), T. silvestris Pocock, 1897 (5-14; Dec-Jan, Apr), T. stigmurus (Thorell, 1876) (10-18; Nov, Jan, Mar), Tityus sp. 1 (T. clathratus group - 7-12; Feb-Apr), Tityus sp. 2 (T. bahiensis group - 2; Mar); and the chactid Brotheas sp. (8-21; Jan, Apr). We observed multiple broods: R. lacrau (offspring in the 2nd brood = 27), T. kuryi (6-16), T. obscurus (2-32), T. silvestris (8), T. stigmurus (4-9), T. bahiensis (offspring in the 2nd brood = 2-18; 3rd = 1), and T. costatus (2nd brood = 18; 3rd = 4). We found statistically significant positive correlation between female size and litter size for T. bahiensis and T. silvestris, and nonsignificant correlation for T. serrulatus.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Protimesius osvaldoi sp. nov. is described from the Reserva Biológica de Sooretama, state of Espírito Santo, southeastern Brazil, being the first record of Stygnidae from this State and the southernmost record of the family in the Brazilian Atlantic Forest (hitherto, the family was recorded down to Bahia only), extending in 210 km south of the previously known distribution. This is a large species, with armature of leg IV very reduced and penial morphology differing from the closest counterparts mainly in the ventral plate, which recedes deeply at the lateral borders and has the distal margin curved ventrally and by the presence of two small intermediate setae. Protimesius Roewer, 1913 consisted hitherto of 17 species, recorded from northern/northeastern Brazil and Amazonia of adjacent countries. A key is given for the 17 species of Protimesius for which males are known.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The description of Micropygomyia brandaoi, a new species of fossil phlebotomine sand fly, is based on one male specimen obtained from Dominican amber of the Miocene period (20 million years). In this new species, the fifth palpal segment is long, the coxite lacks a setal tuft and the style shows four well-developed spines. This set of characters allowed us to place the new species in the genus Micropygomyia Barretto.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The description of Micropygomyia brandaoi, a new species of fossil phlebotomine sand fly, is based on one male specimen obtained from Dominican amber of the Miocene period (20 million years). In this new species, the fifth palpal segment is long, the coxite lacks a setal tuft and the style shows four well-developed spines. This set of characters allowed us to place the new species in the genus Micropygomyia Barretto

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The objective of this study was to carry out a taxonomic review of fossil American phlebotomine sand flies and describe two new species found in amber in the Dominican Republic. The gonostyle of one of these, Micropygomyia dorafeliciangeliae nov. sp., (=Lutzomyia dorafeliciangeliae, species group oswaldoi), has five spines, similar to that of Micropygomyia paterna (Quate, 1963) (= Lutzomyia paterna, species group oswaldoi), but they may be distinguished by the alpha/gamma ratio, which is <1.0 in the new species and >1 in the latter. Pintomyia dominicana nov. sp. (=Lutzomyia dominicana, species group verrucarum) has four spines on the gonostyle and presents a long bristle on the apex of the paramere, which distinguishes it from the other fossil species. With the description of these two new species, a total of 14 species of the American fossil phlebotomine sand flies has been described, 10 of which belong to the genus Pintomyia. An identification key for male fossil species is presented

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aims. We create a catalogue of simulated fossil groups and study their properties, in particular the merging histories of their first-ranked galaxies. We compare the simulated fossil group properties with those of both simulated non-fossil and observed fossil groups. Methods. Using simulations and a mock galaxy catalogue, we searched for massive (>5 x 10(13) h(-1) M-circle dot) fossil groups in the Millennium Simulation Galaxy Catalogue. In addition, we attempted to identify observed fossil groups in the Sloan Digital Sky Survey Data Release 6 using identical selection criteria. Results. Our predictions on the basis of the simulation data are: (a) fossil groups comprise about 5.5% of the total population of groups/clusters with masses larger than 5 x 10(13) h(-1) M-circle dot. This fraction is consistent with the fraction of fossil groups identified in the SDSS, after all observational biases have been taken into account; (b) about 88% of the dominant central objects in fossil groups are elliptical galaxies that have a median R-band absolute magnitude of similar to-23.5-5 log h, which is typical of the observed fossil groups known in the literature; (c) first-ranked galaxies of systems with M > 5 x 10(13) h(-1) M-circle dot, regardless of whether they are either fossil or non-fossil, are mainly formed by gas-poor mergers; (d) although fossil groups, in general, assembled most of their virial masses at higher redshifts in comparison with non-fossil groups, first-ranked galaxies in fossil groups merged later, i.e. at lower redshifts, compared with their non-fossil-group counterparts. Conclusions. We therefore expect to observe a number of luminous galaxies in the centres of fossil groups that show signs of a recent major merger.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Context. Fossil systems are defined to be X- ray bright galaxy groups ( or clusters) with a two- magnitude difference between their two brightest galaxies within half the projected virial radius, and represent an interesting extreme of the population of galaxy agglomerations. However, the physical conditions and processes leading to their formation are still poorly constrained. Aims. We compare the outskirts of fossil systems with that of normal groups to understand whether environmental conditions play a significant role in their formation. We study the groups of galaxies in both, numerical simulations and observations. Methods. We use a variety of statistical tools including the spatial cross- correlation function and the local density parameter Delta(5) to probe differences in the density and structure of the environments of "" normal"" and "" fossil"" systems in the Millennium simulation. Results. We find that the number density of galaxies surrounding fossil systems evolves from greater than that observed around normal systems at z = 0.69, to lower than the normal systems by z = 0. Both fossil and normal systems exhibit an increment in their otherwise radially declining local density measure (Delta(5)) at distances of order 2.5 r(vir) from the system centre. We show that this increment is more noticeable for fossil systems than normal systems and demonstrate that this difference is linked to the earlier formation epoch of fossil groups. Despite the importance of the assembly time, we show that the environment is different for fossil and non- fossil systems with similar masses and formation times along their evolution. We also confirm that the physical characteristics identified in the Millennium simulation can also be detected in SDSS observations. Conclusions. Our results confirm the commonly held belief that fossil systems assembled earlier than normal systems but also show that the surroundings of fossil groups could be responsible for the formation of their large magnitude gap.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We present a new insight on NGC 6034 and UGC 842, two groups of galaxies previously reported in the literature as being fossil groups. The study is based on optical photometry and spectroscopy obtained with the CTIO Blanco telescope and Sloan Digital Sky Survey archival data. We find that NGC 6034 is embedded in a large structure, dominated by three rich clusters and other small groups. Its first and next four ranked galaxies have magnitude differences in the r band and projected distances which violate the optical criteria to classify it as a fossil group. We confirm that the UGC 842 group is a fossil group, but with about half the velocity dispersion that is reported in previous works. The velocity distribution of its galaxies reveals the existence of two structures in its line of sight, one with sigma(nu) similar to 223 km s(-1) and another with sigma(nu) similar to 235 km s(-1), with a difference in velocity of similar to 820 km s(-1). The main structure is dominated by passive galaxies, while these represent similar to 60% of the second structure. The X-ray temperature for the intragroup medium of a group with such a velocity dispersion is expected to be kT similar to 0.5-1 keV, against the observed value of kT similar to 1.9 keV reported in the literature. This result makes UGC 842 a special case among fossil groups because (1) it represents more likely the interaction between two small groups, which warms the intragroup medium and/or (2) it could constitute evidence that member galaxies lost energy in the process of spiraling toward the group center, and decreased the velocity dispersion of the system. As far as we know, UGC 842 is the first low-mass fossil group studied in detail.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Adamussium Jonkersi sp nov is described from the Late Oligocene Destruction Bay Formation Wrona Buttress area King George Island (South Shetlands) West Antarctica The unit characterized by volcanic sandstone is a shallow marine( succession deposited in a moderate- to high-energy environment The thin shelled pectinids collected from the lower part of the unit are preserved mostly as complete valves Shell thickness sculpture pattern and umbonal angle suggest a free-living inactive swimming life habit

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Eusarcus Perty 1833 is one of the oldest described genera of Pachylinae, comprising 36 species distributed from northeastern to southern Brazil (including the central west region), northeastern Argentina, eastern Paraguay and Uruguay. The genus is reviewed and a new classification is proposed based on a cladistic analysis. A cladistic analysis was performed with the 34 valid species of Eusarcus and 11 species belonging to certain Gonyleptidae subfamilies. The data matrix has 67 characters: 14 from dorsal scutum and pedipalp, 38 from male legs and 15 from male genitalia. Two equally parsimonious trees were found (L=319; C. I.=0.26, R. I.=0.61). Pygophalangodus gemignanii uruguayensis Ringuelet 1955a and Pygophalangodus gemignanii gemignanii Mello-Leitao 1931b are here elevated to the category of species, and the following new combinations are proposed: E. catharinensis (Mello-Leitao 1927); E. berlae (Mello-Leitao 1932); E. gemignanii (Mello-Leitao 1931b); E. signatus(Roewer 1949); E. sooretamae (Soares & Soares 1946a); E. uruguayensis (Ringuelet 1955a). The following generic synonymies are proposed: Eusarcus Perty 1833 (type species E. armatus Perty 1833) = Metagraphinotus Mello-Leitao 1927 (type species M. catharinensis Mello-Leitao 1927), Pareusarcus Roewer 1929 (type species P. corniculatus Roewer 1929), Pygophalangodus Mello-Leitao 1931b (type species P. gemignanii-gemignanii Mello-Leitao 1931b) and Antetriceras Roewer 1949 (type species A. signatus Roewer 1949). The following specific synonymies are proposed: Eusarcus hastatus Sorensen 1884 = Pucrolioides argentina Roewer 1913, E. guimaraensi H. Soares 1945, Jacarepaguana pectinifemur Piza 1943, Canestrinia canalsi Mello-Leitao 1931a, and E. maquinensis H. Soares 1966b; E. armatus Perty 1833 = E. curvispinosus Mello-Leitao 1923b, and Enantiocentron montis Mello-Leitao 1936; Eusarcus catharinensis (Mello-Leitao 1927) = E. antoninae Mello-Leitao 1936, E. perpusillus Mello-Leitao 1945, E. tripos Mello-Leitao 1940, and Metagraphinotus trochanterspinosus Soares & Soares 1947b; E. nigrimaculatus Mello-Leitao 1924 = Pareusarcus centromelos Mello-Leitao 1935a, E. furcatus Roewer 1929, Orguesia armata Roewer 1913, and Pareusarcus corniculatus Roewer 1929; E. oxyacanthus Kollar in Koch 1839a = Enantiocentron doriphorus Mello-Leitao 1932, and E. spinimanu Mello-Leitao 1932; E. pusillus Sorensen 1884 = E. vervloeti B. Soares 1944c; E. berlae Mello-Leitao 1932 = Metagraphinotus arlei Mello-Leitao 1935a. Metapucrolia armata (Sorensen 1895) is revalidated, transferred to Eusarcus and considered as a species inquirenda. A new name, Eusarcus metapucrolia is proposed for this species to avoid homonymy with the type species of Eusarcus, E. armatus Perty 1833. Eusarcus aberrans Mello-Leitao 1939a is considered as a species inquirenda. The male of E. teresincola Soares & Soares 1946a is described. Female of the following species are described: E. bifidus Roewer 1929; E. dubius B. Soares 1943b; E. insperatus B. Soares 1944a; E. schubarti Soares & Soares 1946a; E. sooretamae (Soares & Soares 1946a). The following new species are described from Brazil: E. acrophthalmus (type locality: Bahia, Ilheus, Parataquice); E. alpinus (Rio de Janeiro, Santa Maria Madalena, Parque Estadual do Desengano); E. caparaoensis (Minas Gerais, Alto Caparao, Parque Nacional do Caparao); E. cavernicola (Goias, Sao Domingos, Parque Estadual de Terra Ronca, Lapa da Angelica); E. didactylus (Rio de Janeiro, Teresopolis, Parque Nacional Serra dos Orgaos); E. garibaldiae (Santa Catarina, Itajai); E. geometricus (Rio de Janeiro, Teresopolis, Parque Nacional Serra dos Orgaos); E. manero (Rio de Janeiro, Marica, Itaipuacu); E. matogrossensis (Mato Grosso, Chapada dos Guimaraes); E. mirabilis (Minas Gerais, Marlieria, Parque Estadual Rio Doce); E. sergipanus (Sergipe, Itabaiana, Parque Nacional de Itabaiana) and E. tripectinatus (Minas Gerais, Rio Preto). The holotype of E. curvispinosus is proposed as the neotype of E. armatus Perty 1833, the type material of which has been lost. Lectotypes for the following species were designated: E. aduncus; E. hastatus; E. oxyacanthus.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The cuticular surfaces of Cyphophthalmi (Opiliones) were studied in detail, covering a wide range of their taxonomic diversity. Previously unknown structures are described, including a sexually dimorphic row of spines and glandular openings on leg I of Fangensis cavernarum. Scanning electron micrographs of the prosomal paired hairs and the subapical process are provided for the first time. Evidence for the multi-pored nature of the shaft of solenidia as well as the hollowed nature and absence of wall pores of sensilla chaetica are also shown for the first time using scanning electron microscopy. The prosomal paired hairs may constitute a novel autapomorphy for Cyphophthalmi, as they are absent in all studied members of the other species of Opiliones. Finally, the variation in shape of some of the structures examined may be of great taxonomic value.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We herein propose transfer of the two monotypic genera Globibunus (type-species G. rubrofemoratus Roewer, 1912) and Rivetinus (type-species R. minutus Roewer, 1919) to the subfamily Zamorinae (Agoristenidae) and Ramonus (type-species R. conifrons Roewer, 1956), previous placed in Agoristenidae, to the Prostygninae (Cranaidae) based on several characteristics of male genitalia. These transfers are corroborated by a cladistic analysis, which also recovered the three currently recognized agoristenid subfamilies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Traumatic injury to the dentition of dipnoans, indirectly as a result of jaw fracture, or directly from damage to the tooth tissues, is present throughout the history of this group, in fossil and in Recent material. Bones heal, but traces of the injury are retained in the tooth tissues, permanently if the proliferative regions of the tooth plate are injured, or until the damaged dentines are removed by wear if the growing regions are left intact. Lack of resorption and repair of damaged dental hard tissues in dipnoans has implications for some models of tooth plate growth in lungfish with a permanent dentition, because this indicates that lungfish tooth plates may not have the capacity to form reparative dentine as part of the normal growth processes.