Morphologic analyses of a large collection of coleoid cephalopods from the Lebanese Upper Cretaceous yielded a much higher diversity than previously assumed and revealed numerous extraordinarily well-preserved, soft-part characters. An analysis of the Prototeuthidina, a gladius-bearing group with a slender torpedo-shaped body, revealed two species:Dorateuthis syriacaandBoreopeltis smithin. sp. Previously unknown soft-part characters, such as the digestive tract, the gills, and the cephalic cartilage considerably improved our knowledge ofD. syriaca.Since none of the investigated specimens show more than eight arms, similarities with modern squids are regarded as superficial.Boreopeltis smithin. sp. is erected on the basis of its comparatively wideParaplesioteuthis-like gladius. The latter species represents the first unambiguous record of this genus in Upper Cretaceous deposits. Phylogenetic analyses indicate that the prototeuthidid clade consists of two lineages. The plesioteuthidid lineage originates from early JurassicParaplesioteuthisand leads toPlesioteuthisandDorateuthis.The other lineage is morphologically more conservative and leads toBoreopeltis.
Towards a sequence stratigraphic solution set for autogenic processes and allogenic controls: Upper Cretaceous strata, Book Cliffs, Utah, USA
