early triassic carbonate ramp sediments of the lower part of the elika formation are known as vermicular limestone. in the moro mountain, northwest iran, the vermicular limestone includes bioturbated dolomitic mudstone, bioclastic packstone and grainstone, algal calcirudite and intraclastic grainstone. these sediments accumulated in their lower part in open marine subtidal and shoal environment...

In the most complete and first radiometrically dated Precambrian-Cambrian transition strata along the Khorbusuonka River in northern Siberia, a succession of fossilized traces of activity of the earliest infaunal animals has been identified. As supplemented by a similar record in Podolia, the Ukraine and elsewhere. This collection demonstrates that thus far all of the structurally identifiable ...