Rugaspermum minuta - a new species of the seed genus Rugaspermum from the triassic of Nidpur, India

Abstract

This paper provides a description of a new species of Rugaspermum D.D.Pant& Basu, R. minuta Bhowmik & Parveen, from the Nidpur Triassic beds. The dispersed seeds were recovered after macerating large chunks of shale in hydrofluoric acid. The structurally preserved compressed seed is platyspermic, orthotropus, and oval- to barrel-shaped witha shortbeak-like micropyle. The surfaces of the seeds are wrinkled and there is a wide lateral ridge running from the apex to the base on boththe obverse and reverse sides. Upon maceration, the seed yielded 4 membranes: outer, inner, nucellar, and megaspore membranes. The outer cuticle of the integumentis thick and nonstomatiferous, while the inner cuticle is thin and delicate. The nucellar membrane is granular. The megaspore membrane is toughand dark-stained, showing obscure polygonal cell outlines. The pollen chamber is disc-shaped, containing the Rugapites D.D.Pant& Basu type of pollen grains. © TÜBİTAK.