Early Cretaceous ammonites of the superfamily Bochianitoidea from the Butkov Quarry (Central Western Carpathians, Slovakia)

摘要

The paper deals with the description of three heteromorphic ammonites of the superfamily Bochianitoidea that occur in the lower part of the Lower Cretaceous exposed in the Butkov Quarry. In addition to the one-shaft genus Bochianites, two species of the genus Euptychoceras occur in the quarry. Euptychoceras represents three-shaft ammonites with the so-called ptychoceratoid shells. Besides the genus Euptychoceras with a trifid lobe A, a stratigraphically younger group of similar ptychoceratoids co-occur, however, with a rather different suture line. Together with the description of ammonites, the taxonomy of bochianitids, which has been multiply redone and reinterpreted since its "classical" presentation in WRIGHT et al. (1996), is discussed in detail.