Antoniusides

Antoniusides is a genus of extinct marine invertebrates known from fossil deposits dating to the Late Jurassic and Early Cretaceous periods. Described in 1998 by paleontologist L. Navarro, the genus is based on well-preserved dorsal shields recovered from limestone slabs in western Europe. The name Antoniusides is formed from the given name Antonius and the common taxonomic suffix -ides, used to denote a taxonomic lineage.

Taxonomy and species: The broader systematic placement of Antoniusides remains unsettled, with varying affinities proposed by later researchers within adjacent groups of marine invertebrates. Three species have been described: Antoniusides jurassus, Antoniusides cretaceus, and Antoniusides mediterraneus. The type species is Antoniusides jurassus, defined by the original 1998 description.

Morphology: Adult specimens measure approximately 4–8 millimeters in length. The organism displays a dorsoventrally flattened body protected by a shield-like carapace with a radial groove pattern. Marginal spines or projections run along the outer edge, and paired lateral processes are sometimes preserved, giving a comb-like silhouette in dorsal view.

Distribution and habitat: Fossils have been recovered from shallow marine deposits in parts of western Europe and nearby regions of Asia. The morphology and associated fauna suggest a benthic lifestyle, likely detritivorous or scavenging, with mobility ranging from sessile to limited ambulation on the substrate.

Etymology and discovery: The genus name honors the tradition of combining a personal or place-based element with the suffix -ides. Navarro’s 1998 description established the taxon and provided the defining illustration and measurements used in subsequent work.

References: The original description is Navarro, 1998, Journal of Fossil Invertebrates. Later discussions and reviews appeared in subsequent paleontological literature in the early 2000s and 2010s.