[1] The family was first identified in 2016,[2] when fossils of teleosauroid thalattosuchians, including an indeterminate close relative of Lemmysuchus and Machimosaurus, were described from the Middle Jurassic (Bathonian) of Morocco.

[1] Machimosauridae is a diverse group of teleosauroids, phylogenetically defined in the PhyloCode by Mark T. Young and colleagues as "the largest clade within Teleosauroidea containing Machimosaurus hugii, but not Teleosaurus cadomensis.

"[3] The less inclusive subfamily Machimosaurinae is defined in the PhyloCode as "the largest clade within Teleosauroidea containing Machimosaurus hugii, but not Deslongchampsina larteti, Macrospondylus bollensis, and Charitomenosuchus leedsi".

The results of the analysis are shown below:[1] Macrospondylus bollensis Clovesuurdameredeor stephani Charitomenosuchus leedsi Seldsienean megistorhynchus Deslongchampsina larteti Proexochokefalos hebertii cf.

[1][4] Machimosaurines originated in the Bathonian stage of the Middle Jurassic and simultaneously underwent a decrease in snout length but an increase in body size with Neosteneosaurus reaching up to 6.6 m (22 ft) long.