TERRESTRIAL PLANT MICROFOSSILS FROM SILURIAN INLIERS OF THE MIDLAND VALLEY OF SCOTLAND

Palynomorph assemblages comprising sporomorphs (cryptospores and miosp ores) and plant fragments (cuticle-like sheets and tubular structures) were recovered from red-bed sequences in the Lesmahagow, Hagshaw Hill s and North Esk inliers from the Midland Valley of Scotland. The assem blages all indicate an early Wenlock age and probably belong to the ch ulus-nanus Spore Assemblage Biozone. The cryptospore taxa Cheilotetras caledonica gen. et sp. nov. and Pseudodyadospora petasus sp. nov. are proposed, and Tetrahedraletes is emended. The palynomorph and plant m icrofossil assemblages consist of entirely land-derived forms except i n the North Esk inlier where rare acanthomorph acritarchs were recover ed from a single horizon. Palynology thus provides additional evidence that the deposits in the Lesmahagow and Hagshaw Hills inliers accumul ated in a non-marine environment, whereas a brief marine incursion int errupted terrestrial fluviatile deposition in the North Esk inlier. Th is report describes rare examples of Silurian palynomorph assemblages of entirely land-derived forms.