The sets have all been reversed so that you can print it on the back side of cardstock or patterned paper for scrapbooking or cardmaking. You can learn to make your own printable block letters using most fonts and Word Art in Microsoft Word.he sets have all been reversed so that you can print it on the back side of cardstock or patterned paper for scrapbooking or cardmaking. You can learn to make your own printable block letters using most fonts and Word Art in Microsoft Word.
The Cretaceous also saw the first radiation of the diatoms in the oceans (freshwater diatoms did not appear until the Miocene). The Cretaceous-Tertiary extinction. The most famous of all mass extinctions marks the end of the Cretaceous Period, about 65 million years ago.As everyone knows, this was the great extinction in which the dinosaurs died out, except for the birds, of course.he Cretaceous also saw the first radiation of the diatoms in the oceans (freshwater diatoms did not appear until the Miocene). The Cretaceous-Tertiary extinction. The most famous of all mass extinctions marks the end of the Cretaceous Period, about 65 million years ago.
Many species vanished in five cataclysmic mass extinctions and today, 99.9 percent of all species that have existed on Earth are extinct. T he Ordovician-Silurian extinction occurred about 439 million years ago due to a drop in sea levels as glaciers formed followed by rising sea levels as glaciers melted.During this extinction 25 percent of marine families and 60 percent of marine genera (the classification above species) were lost. he Ordovician-Silurian extinction occurred about 439 million years ago due to a drop in sea levels as glaciers formed followed by rising sea levels as glaciers melted. During this extinction 25 percent of marine families and 60 percent of marine genera (the classification above species) were lost.