drepanopterus वाक्य

"Drepanopterus pentlandicus " was first described from the Silurian strata of the Pentland Hills in Scotland.
The only other fully described valid species is " Drepanopterus abonensis ", from the Upper Devonian of Portishead, Somerset.
Recent work however confirms them to be a derived member of the suborder Stylonurina, with the genus " Drepanopterus " being a basal member of their superfamily.
The exact relationship of " Drepanopterus " to other Eurypterids has long been unclear, however it is now apparent that it is a primitive hibbertopteroid, and an early relative of the Carboniferous " Hibbertopterus ".
The genus has in the past been assigned its own family, with nine species associated with the genus " Drepanopterus ", however five of these have since been proven to be synonyms of pre-existing species, assigned to their own genera, or found to be based on insubstantial fossil data ( the holotype of one proved to be a lithic clast ).