Rule 41. Dismissal of Actions
. . .
(b) Involuntary Dismissal; Effect. If the plaintiff fails to
prosecute or to comply with these rules or a court order, a defendant
may move to dismiss the action or
any claim against it. Unless the dismissal order states otherwise, a
dismissal under this subdivision (b) and any dismissal not under this
rule — except
one for lack of jurisdiction, improper venue, or failure to join a
party under Rule 19 — operates as an adjudication on the merits.