s sa sb sc sd se sf sg sh si sj sk sl sm sn so sp sq sr ss st su sv sw sy

Перевод: Silurian

[прилагательное]
силурийский;
[существительное]
силурийский период

Тезаурус:

1. Similar species can be found in Silurian limestones all over Europe and North America.
2. 5 The tabulate coral Halysites escharoides (chain coral) form The Silurian of Ohio Falls, USA.
3. Most of the later graptolites had only a few branches and, in the Silurian, species with only a single branch tend to dominate the assemblages.
4. Silurian fossils very like the "living fossil" Neopilina ( above ), and the peculiar Cambrian form Yochelcionella ( below ).
5. Gastropods of this kind are typical of Ordovician and Silurian strata, where there are a number of genera and many species of comparable form.
6. 23 The Silurian cystoid, Pseudocrinites magnificus , Wenlock limestone, England.
7. The nautiloids achieved their widest range of adaptations and greatest variety of form in the Ordovician and Silurian periods, with various coiled forms, straight, pipe-like forms, and curious dumpy species with restricted apertures that may have adopted a sluggish (possible filter-feeding) mode of life.
8. This sort of preservation is very common in European Ordovician and Silurian rocks.
9. Within the marine environment itself some palaeontologists believe that the overall richness of the marine fauna was established early on, say by the Silurian period, and that there has not been a great increase in the total number of species living in the sea at any one time since then, although of course the kinds of organisms inhabiting the sea have changed many times.
10. Not only that, the living form had hardly changed from its Silurian predecessor ( see p. 77).
11. Although the number of species may have been at least approximately the same in marine environments for the last 300 million years or so the kinds of fossils have changed repeatedly, so that, for example, in marine limestones of Silurian age the shelled brachiopods may number dozens of species, whereas in similar looking limestones of Eocene age no brachiopods at all can be found, but there may be as many species of gastropods of kinds unknown in Silurian rocks.
12. The most mouthwatering specimens tend to be found in limestones - famous sites are in the Silurian rocks of England and Mississipian rocks of the U.S.A. The group as a whole had a major crisis in the Permian, during which most of the Palaeozoic forms died out.