Gavialimimus

Gavialimimus Temporal range: Late Cretaceous,
Reconstructed skeleton of an indeterminate Moroccan plioplatecarpine, possibly G. ptychodon
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Clade:	†Mosasauria
Family:	†Mosasauridae
Clade:	†Russellosaurina
Clade:	†Selmasaurini
Genus:	†Gavialimimus Strong et al., 2020
Type species
†Gavialimimus ptychodon Arambourg, 1952

Gavialimimus is an extinct genus of plioplatecarpine mosasaur from the Maastrichtian of Morocco and possibly Angola. It was a medium-sized mosasaur measuring around 6 metres (20 ft) in total body length. Remains of Gavialimimus were first described by French paleontologist Camille Arambourg in 1952 as a novel species of Platecarpus, P. ptychodon. In 2015, Nathalie Bardet and colleagues referred a more complete material to this species and recognized that P. ptychodon to be a distinct genus from Platecarpus, however, no taxonomic revisions were made. In 2020, Catherine Strong and colleagues described Gavialimimus almaghribensis, a new genus and species of plioplatecarpine mosasaur, and rejected the validity of P. ptychodon as they found the fragmentary type material to be ultimately non-diagnostic. In a comprehensive 2025 study of mosasaur teeth from the Maastrichtian of Morocco, Bardet and colleagues found the type material of P. ptychodon to be diagnostic and differing from teeth of all other mosasaurid species excluding G. almaghribensis. Thus, they considered the latter species a junior synonym of the former, and proposed the new combination G. ptychodon.

Discovery and naming

The holotype MHNM.KHG.1231, an articulated skull and associated fragmentary postcrania, was found in the Ouled Abdoun Basin. In 2023, a 4 metres (13 ft) long specimen from Angola identified as Gavialimimus sp. was found within the guts of Prognathodon kianda.

The etymology of this genus means "gharial mimic" (Hindi Gavial = "gharial" + Greek mimus = "mimic"). The genus name refers to morphological convergence between Gavialimimus and the extant gharial (Gavialis gangeticus). Gavialimimus has been said to occupy the niche of a large piscivore. In this way, through severe specialization, it managed to co-exist with several other large mosasaur species in the same area.

Classification

In their 2024 description of the Moroccan plioplatecarpine Khinjaria, Longrich et al. used phylogenetic analyses to recover it within a clade of non-plioplatecarpin plioplatecarpine mosasaurids. They named this clade—also containing Gavialimimus, Goronyosaurus and Selmasaurus—the Selmasaurini. A similar clade was recovered by Strong et al. (2020) in their description of Gavialimimus. The results of the analyses of Longrich et al. are shown in the cladogram below:

	Tethysaurus Plioplatecarpinae Russellosaurus Yaguarasaurus columbianus Carlile Formation plioplatecarpine Yaguarasaurus regiomontanus Ectenosaurus spp. Angolasaurus Plioplatecarpini Selmasaurini Selmasaurus johnsoni Selmasaurus russelli Gavialimimus Goronyosaurus Khinjaria