Members of the ____ subphylum are now all extinct, but they were extremely numerous in shallow Paleozoic seas. Most of them were dorsoventrally flattened and heavily armored, with two deep longitudinal grooves that gave their body a three-lobed appearance.

Question

Quizplus · Accepted Answer

Trilobita is the correct answer because members of this subphylum were indeed all extinct and were known for their three-lobed body appearance, which is characteristic of the trilobites. They thrived in the Paleozoic era and were dorsoventrally flattened and heavily armored.

Members of the ____ Subphylum Are Now All Extinct, but They