Crinoid stem, Devonian or later, Lake Michigans Left Coast, Elizabeth Fagan, Roscoes Relics

Brachiopods, Lucy, and Extinction

Lake Michigan's Left Coast reveals Paleozoic limestone and dolomite dating to the Devonian Period (420–350 million years ago). Abundant in rocks from the Paleozoic are fossilized brachiopods, marine animals with upper and lower hard shells hinged at the rear. Though they first appear in rocks dating to the early Cambrian Period (540–485 million years ago), brachiopods reached … Continue reading Brachiopods, Lucy, and Extinction

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Faces of extinction, fossils on Lake Michigans Left Coast, Elizabeth Fagan dba Roscoes Relics

Faces of Extinction 3

When mass extinctions occur, as they have five times previously in Earth's history, every member of a given species expires. Not just the old, the infirm, those who have a certain vulnerability. All members of the species die, even the babies. After spotting dozens of limestone skulls of extinct creatures on Lake Michigan's Left Coast, … Continue reading Faces of Extinction 3

Faces of extinction, fossils on Lake Michigans Left Coast, Elizabeth Fagan dba Roscoes Relics

Faces of Extinction 2

Over its 4.6 billion-year history, Earth has changed many times, in many ways. Homo sapiens, the name we give ourselves, evolved a few million years ago, a tiny point in time when Earth's conditions were just so. A peculiar trait of a certain subgroup of Homo sapiens, aka humans, put itself at the center of … Continue reading Faces of Extinction 2

Faces of extinction, fossil skulls on Lake Michigans Left Coast, by Elizabeth G Fagan

Faces of Extinction 1

As children we wondered, "Why don't we see living dinosaurs?" "Because they are extinct," a parent or teacher told us. And we learned that "extinct" is an adjective meaning "of a species, family, or other larger group having no living members." (oxforddictionaries.com) We might further learn such facts as: "Species become extinct for many reasons, … Continue reading Faces of Extinction 1