The Staré Město Belt (SMB) in the Central Sudetes forms a Variscan tectonic boundary zone that is located between Saxothuringian and Brunovistulian terranes of Bohemian Massif. three thrust-bounded upper, middle lower lithotectonic units SMB are composed metasedimentary Late Cambrian metavolcanic rocks. A new LA-ICPMS zircon geochronology supported by typology studies mica schists upper unit mi...

ECOS III The slender, spine-shaped, apatitic protoconodonts appear in the fossil record near the Precambrian-Cambrian boundary and persist through the Cambrian . Recent work (Szaniawski 1 982, J. Paleont. 56) suggests that protoconodont elements were homologous to the grasping spines of modern chaetognaths . Paraconodonts are similar to protoconodonts in their mode of growth by basal accretion ...

Echinoderms possess a skeleton with a unique and distinctive meshlike microstructure called stereom that is underpinned by a specific family of genes. Stereom is thus considered the major echinoderm synapomorphy and is recognized already in some Cambrian echinoderm clades. However, data on the skeletal microstructures of early echinoderms are still sparse and come only from isolated ossicles of...

The Meishucun Section (Yunnan Province, South China) is considered to be an important Precambrian–Cambrian boundary section, primarily because of its rich small shelly fossil record. In this article, we report the results of a sulphur isotope study of phosphate-bound sulphate from the Meishucun Section and several correlative sections in South China. Forty clastic, granular phosphorites from Me...

Bioturbation long has been ‘blamed’ for eliminating late Proterozoic-style sedimentary structures and fabrics. While the presence of diverse and complex burrows in lowermost Cambrian strata is indisputable, analysis of Precambrian– Cambrian successions in southeast Newfoundland demonstrate that this burrowing style did not produce typical Phanerozoic-style ichnofabrics. Three hundred meters of ...

Microbialites are the most abundant life evidence in Precambrian sedimentary rocks. They produced by microbial interaction activity and processes reflecting paleoenvironmental conditions. The Ediacaran-Cambrian carbonate siliciclastic successions Southern Amazon Craton Central Brazil, provide a key opportunity to understand how metazoan coexisted with communities. spatial temporal distribution ...

New U-Pb ages for detrital and igneous zircons constrain the depositional age and sedimentary provenance of the Beardmore Group, a siliciclastic succession that records transformation of the East Antarctic margin during Rodinia breakup and subsequent Gondwana amalgamation. We divide rocks previously mapped as the Beardmore Group into (1) an inboard late Neoproterozoic assemblage (probably ≤670 ...

BACKGROUND Extant cubozoans are voracious predators characterized by their square shape, four evenly spaced outstretched tentacles and well-developed eyes. A few cubozoan fossils are known from the Middle Cambrian Marjum Formation of Utah and the well-known Carboniferous Mazon Creek Formation of Illinois. Undisputed cubozoan fossils were previously unknown from the early Cambrian; by that time ...

—One of the enduring puzzles to Stephen Jay Gould about life on Earth was the cause or causes of the fantastic diversity of animals that exploded in the fossil record starting around 530 Ma—the Cambrian explosion. In this contribution, we first review recent phylogenetic and molecular clock studies that estimate dates for high-level metazoan diversifications, in particular the origin of the maj...