Morphometric study and taxonomic revision of Metopaster species (Asteroidea, Echinodermata) from the Coniacian-Campanian of Northern Aquitaine

Isolated ossicles of sea stars are commonly collected in the Santonian-Campanian series of northern Aquitaine. The most prominent elements are the marginal ossicles of Metopaster, and especially the enlarged distal superomarginals (EDS) that can reach size of >20 mm. They show enough variation in their features to allow species-level differentiation. Five closely related species were previously recognised, including Metopaster loirensis Gale, 1987b, M. trichilae Breton, 1992, M. chiliporus, M. hypertelicus Breton, 1992, and M. stratiferus. A new comprehensive sampling led to a report of the first occurrences of M. praetumidus in the Aquitaine basin and the definition of six new species: M. boudinus sp. nov. M. boutillieri sp. nov. M. brebis sp. nov. M. glarea sp. nov. M. sandalina sp. nov. and M. fa sp. nov. The two subspecies of M. trichilae are elevated to species level: M. trichilae and M. minor. The species delineation is supported by a 3D morphometric studies of the EDS. All species are redescribed based on all available ossicles, including EDS, superomarginals, inferomarginals, and occasionally, abactinals, actinals and adambulacrals. Two informal species groups, M. gr. loirensis and M. gr. stratiferus, are distinguished based on shape, size and ontogenetic trajectories of the EDS ossicles.urn:lsid:zoobank.org:pub:53279CAC-BFE9-4403-A6B7-751FBB9C49E9