Machimosauridae is an extinct family of teleosauroid thalattosuchian crocodyliforms.[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. The family was largely expanded in 2020 when the systematics of Teleosauroidea were re-reviewed. Members of this family generally were larger than the teleosaurids.
Machimosauridae is a diverse group of teleosauroids, phylogenetically defined as "the largest clade within Teleosauroidea containing Machimosaurus hugii, but not Plagiophthalmosuchus gracilirostris and Teleosaurus cadomensis." The members of the Machimosauridae share several unique characters among teleosauroids, which are:
The phylogenetic relationships of the Machimosauridae were analyzed in a comprehensive analysis of teleosauroid relationships. The results of the analysis are shown below:
Machimosaurids grew in body size and diversified feeding strategies throughout their evolutionary history. Primitive machimosaurids, such as Macrospondylus and Charitomenosuchus, were longirostrine (long-snouted) generalists with body lengths less than 5m (16feet) long.[3] 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 6.6m (21.7feet) long. Machimosaurins were the largest teleosauroids, with body lengths up to 7.1m (23.3feet) (Machimosaurus rex), and were durophagous hunters, meaning they fed on hard prey.