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21.
The recently discovered late Triassic vertebratelocality at Chulabhorn Dam (North-Eastern Thailand) has yielded incomplete remains (jaw fragments and teeth) of phytosaurs, which are apparently indicative of a form related to Belodon and Rutiodon. They can be interpreted as showing that in the late Triassic North-Eastern Thailand was already biogeographically part of Laurasia. 相似文献
22.
Radiolarians of several radiolarites sections of the Pindos-Olonos zone, southern Peloponnesus, lead to propose direct datations of mesozoic sediments. The acuity of such datations allow to distinguish two periods for depositionof radiolarites s.s. in the tethyan region. The first period would be Upper Jurassic and general in tethyan realm, radiolarites depositing under various latitudes (0–35°N). This would be the result of a strong ocean surface current. The second period would be Upper Cretaceous (Vraconian—Coniacian) and be geographically much more restricted (0–15°N). This could result from a weaker current. The absence of radiolaritic sedimentation is possibly the result of the destruction or insulation of the accurate basins during the obduction of ophiolites on the apulo-african realm. The inventory of Late Cretaceous radiolarian fauna, rarely done on alpine series so far, shows similar result to those obtained in Central American and California. 相似文献
23.
A large sample of skulls and associated dentitions of Cormohipparion sphenodus (Cope, 1889). new combination, is described from Miocene deposits of Nebraska, Colorado, New Mexico, and California. This species is morphologically more advanced than the most primitive species of the genus, C. goorisiMacFadden & Skinner, 1981, and more primitive than a third and more advanced species of this genus. C. occidentale (Leidy, 1856). In several characters such as configuration of the preobrital fossa, size, hypsodonty, shape of protocone, and complexity of enamel plication, C. sphenodus is morphologically similar, and potentially related to, some Old World Vallesian «Hipparion. In addition, based on radiometric calibration of stratigraphic sequences in Nebraska and California, C. sphenodus spans an interval of time from about 13.6 to 11 Ma. Inasmuch as the Old World «Hipparion Datum is calibrated at about 12 Ma, we conclude that C. sphenodus exhibits the morphological and chronological prerequisites to have been directly ancestral to some of these Old World forms.The hipparion horses apparently were a polyphyletic assemblage of several genera, and their biogeographic and biochronologic history is more complex than classically thought. Several dispersal events involving these horses may have occurred between the New and Old Worlds during the late Miocene. 相似文献
24.
Patrick De Wever 《Geobios》1981,14(1):5-15
Studies of skeleton elements of several jurassic species of Saitoum allow to compare them with Poulpus from Trias. The sub-family Poulpinae is introduced, caracterised by three cephalic arcs and the collar position of the cephalic structure. Among the jurassic forms, 4 species are newly described: S. corniculum, S. elegans, S. levium and S. trichylum. 相似文献
25.
Michel Melou 《Geobios》1981,14(1):69-87
Three species of Isorthidae are described in the Lower Devonian of the Armorican Massif. Two of them were hitherto badly known, being never adequately described nor figured: Isorthis (Protocortezorthis) miloni from the Gahard Formation (Gedinnian) and Isorthis (Protocortezorthis) trigeri from the Saint-Céneré Formation (Gedinnian-Siegenian). Isorthis oehlertiSolle, 1976 is considered as a synonym of Isorthis (Protocortezorthis) trigeri. The geographic distribution of these species allows to corroborate that until the top of the Lower Devonian (top of Le Faou Formation), two provinces with different faunal associations exist in the Armorican Massif. 相似文献
26.
The first mammalian remain ever found in NewCaledonia is an upper tooth found by golddiggers in the Plio-Pleistocene terrace from the Diahot river. This tooth, given to the Muséum national d'Histoire naturelle (Paris) in 1876, was determined as a rhinoceros tooth and then completely forgotten. Its detailed study shows that it belongs to Zygomaturus, a large marsupial diprotodontid genus whose story is rather complicated. The Diahot tooth represents a new species of Zygomaturus, Z. diahotensis nov. sp., close to Z. trilobus from the Australian Pleistocene. That kinship suggests a Plio-Pleistocene land connection between Australia and New Caledonia, whereas till now New Caledonia was supposed to be separated from Australia since the end of the Cretaceous, because of the total absence of indigenous mammals, fossil or recent, in New Caledonia. The latest geological studies in the East Pacific do not contradict our hypothesis. 相似文献
27.
The geologic section of the Torrente Scrivia in 061 the vicinity of Rigoroso is generally reported as an conformable sequence in Oligocene and Miocene strata.In fact, it has suffered important reworkingsduring Lower Miocene and this event is not only evident in sedimentology but also in paleontology. Locally, these events reflect tectonic motions more strongly marked in the north-eastern part of the ligurian piemontese basin.Consequently, the result is that the geologicsection concerned could not be satisfactory referring to Lower Miocene. 相似文献
28.
29.
Michel Brunet 《Geobios》1979,12(5):653-673
A screen washed and hand sorted sample of six tons sediments from La Milloque (Lot-et-Garonne) has yielded to the author several thousand micromammal's teeth. Among the Rodents, four extinct species of Cricetids have been recognized: Eucricetodon praecursor (Schaub, 1925); Adelomyarion viretiHugueney, 1969; Pseudocricetodon cf. thaleri (Hugueney, 1969); Melissiodon quercyiSchaub, 1920. The fossil remain's study affords many paleontological informations more particularly for E. praecursor, a previously poorly known species. About the upper Oligocene biochronology the four species' evolution degrees prove the statute of reference locality attributed to La Milloque, «mammalian timemark just below the reference locality of Coderet (Allier). Moreover it's pointed out that the locality of Rickenbach (Switzerland) is slightly older than La Milloque, whereas an intermediate age between La Milloque and Coderet can be suggested for the locality of Dicupentale (Tarn-et-Garonne). 相似文献
30.
Systematic revision of the genus Steginoporella: until now about eighty species were described. Only twenty recent species and thirty-four fossil ones are maintained. Several species and subspecies are new.The main interest of this revision is to establish a biostratigraphical scale: the settlement of this scale is based on the known stratigraphical distribution and on an attempt of phylogeny.The second advantage is ecological: all recent species live in marine tropical environment. The Steginoporella are good paleoecological indicators.At last, the establishment of a paleobiogeography, even incomplete and not definitive, allows to understand more easily recent distribution of Steginoporella connected with the great events of earth evolution. 相似文献