Metapterygoid-quadrate fenestra (QMF) in cleared and double stained Clupeidae. A Hyopalatine arch, jaws and opercular series of Alosa sapidissima, TCWC 5264.01, 63.7 mm SL. B Close up of QMF, same specimen as in A . C QMF of Brevoortia patronus, TCWC 19718.02, 51.0 mm SL. Abbreviations: An, angulo-articular; Apa, autopalatine; De, dentary; Ecpt, ectopterygoid; Enpt, endopterygoid; Hy, hyomandibular; Iop, interopercle; Met, metapterygoid; Mx, maxilla; Op, opercle; Pmx, premaxilla; Pop, preopercle; Q, quadrate; Ra, retroarticular; Sop, subopercle; Spmx, supramaxilla; Sy, symplectic.