Two specimens of a new spider from the Cretaceous (ca. 129 Ma) El Montsec Fossil-Lagerstätte, northeastern Spain, are described as Montsecarachne amicus gen. et sp. nov. and referred to the extant haplogyne family Plectreuridae. Plectreurids are found today in only in the southwestern USA, Mexico, Central America and Cuba, but fossils show a more widespread distribution in Eurasia. The new species adds an additional stratigraphic and biogeographical record. The paleobiogeographical history of plectreurids is discussed, and it is concluded that the most likely scenario is that the family was more widespread in the past, and has suffered extinction over much of its range, resulting in the present distribution. Possibly, extant plectreurids represent a living remnant of a more diverse group of haplogynes that were widespread in the Mesozoic.