ABSTRACT

Examination of isolated shark teeth from the uppermost lower Campanian Gonioteuthis quadrata scaniensis Zone of southern Sweden revealed the presence of a rare, previously undescribed lamniform shark. The unusually small-sized anterior teeth, variable presence of a short and shallow median groove, cusplet shape and outline of posterior teeth indicate a dallasiellid affinity and the species is formally described as Dallasiella brachyodon sp. nov. It is the youngest record of dallasiellids and adds to the extraordinarily high diversity of lamniform sharks in the uppermost lower Campanian of the Kristianstad Basin. Over its 18 Ma range, Dallasiella appears to have increased in body size and developed teeth with relatively broader cusps, indicating enhanced capabilities for tackling larger prey.

摘要

对来自瑞典南部坎帕尼亚最上层的Gonioteuthis quadrata scaniensis区的孤立鲨鱼牙齿进行检查后发现，存在一种罕见的、以前未描述过的片状鲨鱼。异常小的前牙、短而浅的正中沟、尖顶形状和后牙轮廓表明与 dallasiellid 亲缘关系，该物种被正式描述为Dallasiella brachyodon sp。十一月 这是 dallasiellids 最年轻的记录，并增加了克里斯蒂安斯塔德盆地最上部的下坎帕尼亚的 lamniform 鲨鱼的异常高的多样性。在其 18 Ma 范围内，Dallasiella似乎体型有所增加，并且牙齿的牙尖相对较宽，这表明处理较大猎物的能力有所增强。