SUMMARY ORDER

When they filed this putative class action, plaintiffs were six lawful permanent residents awaiting decisions on their naturalization applications. They sued (1) to expedite the processing of their naturalization applications and those of putative class members, and (2) to invalidate the policy of conducting Federal Bureau of Investigation name checks on each naturalization application. They now appeal the dismissal of their complaint, the denial of class certification, and the denial of their motion for reconsideration. We as *575 sume the parties’ familiarity with the facts and the record of prior proceedings, which we reference only as necessary to explain our decision.

Preliminarily, we must consider whether we have jurisdiction over the appeal. Because the six named plaintiffs have been naturalized, the government urges us to dismiss the appeal as moot. See, e.g., Lillbask ex rel. Mauclaire v. State of Conn. Dep’t of Educ., 397 F.3d 77, 84 (2d Cir. 2005) (“When the issues in dispute between the parties are no longer live, a case becomes moot, and the court — whether trial, appellate, or Supreme — loses jurisdiction over the suit, which therefore must be dismissed.” (internal citations and quotation marks omitted)). When a class action has been certified, mootness of the dispute between the named plaintiff and the defendant does not render other class members’ claims nonjusticiable. See, e.g., Sosna v. Iowa, 419 U.S. 393, 401, 95 S.Ct. 553, 42 L.Ed.2d 532 (1975). Here, however, no class has yet been certified. In such cases, the Supreme Court has allowed named plaintiffs whose individual claims have become moot to appeal only the denial of class certification. See United States Parole Comm’n v. Geraghty, 445 U.S. 388, 404, 100 S.Ct. 1202, 63 L.Ed.2d 479 (1980).

Plaintiffs’ opening brief mentions the class certification issue in a lone footnote. While we generally “do not consider an argument mentioned only in a footnote to be adequately raised or preserved for appellate review,” United States v. Restrepo, 986 F.2d 1462, 1463 (2d Cir. 1993), we nevertheless retain “ample discretion to excuse such a failure,” Salahuddin v. Goord, 467 F.3d 263, 276 n. 6 (2d Cir. 2006). We do so here because (a) there was no surprise to the government, (b) the district court rested its class certification decision on the merits of plaintiffs’ claims, and (c) plaintiffs have now extensively argued the issue. See id.; Mitchell v. Fishbein, 377 F.3d 157, 164-65 (2d Cir. 2004).

Because the district court did not address the requirements for class certification separately from the merits of plaintiffs’ claims and our jurisdiction depends on resolution of that issue, we vacate the denial of class certification and remand for the district court to consider class certification in the first instance. In considering, on remand, whether the prerequisites for a class action are satisfied, see Fed.R.Civ.P. 23(a), the district court will need to decide who, if anyone, can “fairly and adequately” represent the class, including representing the class on appeal from dismissal, id.; see also United States Parole Comm’n v. Geraghty, 445 U.S. at 405-07, 100 S.Ct. 1202. It may also consider whether to construct sub-classes based, in part, on the discrete agency action that particular class members ask the court to compel. See Fed.R.Civ.P. 23(c)(5); see also 5 U.S.C. § 706(1); Norton v. S. Utah Wilderness Alliance, 542 U.S. 55, 64, 124 S.Ct. 2373, 159 L.Ed.2d 137 (2004).

Accordingly, we VACATE the judgments in part, and REMAND the case to the district court for further proceedings consistent with this order.