Article: Dichograptid synrhabdosomes from the Arenig of Britain

Dichograptid synrhabdosomes are reported for the first time. Synrhabdosomes of Didymograptus aff. simulans Elles and Wood from Arenig Fawr, North Wales and Azygograptus lapworthiNichohon from near Keswick, Lake District, are described, both from the Arenig Series (extensus Zone). Possible reconstructions of synrhabdosomes of D. aff. simulans are attempted. It is suggested that synrhabdosomes acted as mechanisms to promote rapid breeding in short-lived, highly favourable environmental conditions.