First record of elasmobranchs from the Lower Cretaceous of Argentina (Neuquén Basin)

The material reported herein comes from the Lower Cretaceous Agrio Formation (Neuquén Basin, west-central Argentina). These fishes dwelled in a Pacific Ocean embayment in southwestern Gondwana before the establishment of the Andean Cordillera. The material consists of an incomplete dorsal fin spine of the widespread Hybodontoidea clade (from upper Valanginian beds) and a partial tooth of one of the earliest known lamniforms (from upper Hauterivian beds).