Complex sentence: The Ecphoras, named after the genus "Ecphora", is a group of extinct predatory ocenebrinid murexes descended from the Eocene murex, "Tritonopsis", indigenous to the North American Eastern Seaboard from the Eocene until their extinction during the Pliocene.
Split into simpler sentences: The Ecphoras, named after the genus "Ecphora", is a group of extinct predatory sea snails, marine gastropod mollusks in the family Muricidae, the rocks snails or murexes. These ocenebrinid murexes descended from the Eocene murex, "Tritonopsis", which was indigenous to the North American Eastern Seaboard from the Eocene until their extinction during the Pliocene.