SILURIAN AND CAMBRIAN FOSSILS,Antique Archeology Print,1894 Antique Wood Engraving

Historical Collectible Art Print

The Silurian is a major division of the geologic timescale that extends from the end of the Ordovician period, about 443.7 ± 1.5 Ma (million years ago), to the beginning of the Devonian period, about 416.0 ± 2.8 Ma (ICS 2004). As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by 5-10 million years. The base of the Silurian is set at a major extinction event when 60% of marine species were wiped out. The Cambrian is a major division of the geologic timescale that begins about 542 mya (million years ago) at the end of the Proterozoic eon and ended about 488.3 mya with the beginning of the Ordovician period (ICS, 2004). It is the first period of the Paleozoic era of the Phanerozoic eon.The Cambrian is the earliest period in whose rocks are found numerous large, distinctly fossilizable multicellular organisms that are more complex than sponges or medusoids. During this time, roughly fifty separate major groups of organisms or "phyla" (a phylum defines the basic body plan of some group of modern or extinct animals) emerged suddenly, in most cases without evident precursors (Gould, 1989). This radiation of animal phyla is referred to as the Cambrian explosion.

Approximate Overall Size: 6 X 9 1/2 inches

CONDITION: Book Plate - Excellent Condition. As Scanned. German Text. Beautiful with excellent detail. SINGLE PAGE PRINT ON THE FRONT AND BACK