Acta Palaeontologica Polonica

Callipterid pteridosperms from the Early Permian of Ukraine

Natalya Boyarina

Acta Palaeontologica Polonica 39 (1), 1994: 117-133

In terrigenous rocks of the early Permian age, below the limestone P6, of the Western Donets Basin two new pteridosperm species have been identified. One of them had phyllosperms with seed scars situated near the base and in the middle part of a pinnule, at the ends of vein-like off-shoots. Its foliage consists of dichotomously branched pinnate to tripinnate fronds, sphenopteroid pinnules and intercalary pinnae and pinnules. The foliage is very variable. Immature, semi-mature, and mature pinnae and pinnules are known. These plants grew probably along tJle margins of floodplain lakes. The narne Raminervia mariopteroides gen. et sp. n. is proposed here for them. The second species, Dictaphyllum cuneata sp. n., is characterized by pinnate to bipinnate fronds with a dichotomy of the primary rachis, broadly wedge-shaped pinnules and similarly shaped intercalary pinnules. Plants of the species probably grew on elevated lots of the floodplain and on the alluvial-lacustrine plain.

Key words: pteridosperms, natural genus, Early Permian, Ukraine, paleoecology.


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