Nilssoni–scanicusZone deposits (Silurian, early Ludlow) from the Leintwardine and Long Mountain districts of Britain, and the Cǎlǎrasi Borehole, Moesian Platform of Romania, have yielded a species of monograptid which, whilst resembling rare LudlowMonoclimacisspecies, has strong morphological affinities with Devonian monograptids such asMonograptus ramstalensisJaeger. Because of the occurrence of such structures at a surprisingly low horizon the writers urge caution in identifying age from monotypic assemblages. The difficulties surrounding the affinities of the low Ludlow species necessitates a provisional open nomenclature asMonograptussp. The possible evolutionary significance is discusse