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The examined Ariidae marine catfish from the Neogene of tropical America consisted of isolated skulls, otoliths and bone fragments, some of which were described independently as otolith-based species or skull-based species. We used three-dimensional digital rendering (microCT) of skull and otolith reconstructions to recognize anatomical patterns including skull-otolith morphology, spatial allocations of otoliths in the endocranium for taxonomic identifications. We recognized isolated Proto-Caribbean otoliths of Cathorops sp. from the late early Miocene to early Pliocene formations and isolated otoliths of † Aspistor verumquadriscutis , † Bagre urumacoensis and Notarius sp. from the late Miocene. We explored the endocrania of four fossil Ariidae skulls from the late Oligocene to late early Miocene Proto-Caribbean to determine their internal otolith-cranial morphology, and we identified and described the skulls of † Bagre protocaribbeanus and † Cantarius nolfi and erected the new species of † Bagre castilloensi n. sp. and † Bagre ornatus n. sp. based on the internal otolith-skull association. The first fossil record of Bagre marinus from the early Pliocene Cubagua Formation to the late Pliocene San Gregorio Formation completed the ariid geochronological sequence. We discuss the differential stages of fossil preservation of bioapatite skulls and aragonite otoliths according to the diagenetic processes as well as the paleoenvironmental conditions in the sedimentary basins. Detailed microCT, 3D reconstructions, X-rays, dry prepared skeletons and digital photos of otolith and skull are shown to elucidate the in-skull otoliths species descriptions. • The research provides the first descriptions of Neogene Ariidae catfish in-skull otolith and the erection of new species. • Neogene otoliths and in-skull otolith based species reinforce the paleodiversity of Ariidae. • MicroCT and 3D reconstructions elucidate the fossil in-skull otolith Ariidae species. [ABSTRACT FROM AUTHOR]

The Miocene fiddler crab Uca maracoani antiqua Brito, 1972, from the Pirabas Formation (Brazil), has been recurrently claimed to be a valid species and the oldest fossil record of the brachyuran crab family Ocypodidae. However, morphological investigations with the aid of microCT scan images of a large number of topotypic specimens and re-examination of the type material of U. maracoani antiqua revealed that it should actually be merged into the synonymy of Uca (Acanthoplax) maracoani (Latreille, 1802). Therefore, U. maracoani , the morphology and ecological traits of which have persisted essentially unchanged for at least 16 Ma (Burdigalian to present), is actually a long-lived crab species inhabiting an estuarine, sheltered mudflat environment that, likewise, has essentially remained unchanged. Burgeoning evidence suggests that evolutionary stasis may not be uncommon among mangrove crabs, as revealed by Afruca tangeri (Eydoux, 1835) from the middle Miocene in northeastern Spain and U. ornata (Smith, 1870) from the Plio-Pleistocene in Honduras. Uca antiqua is redescribed and illustrated based on 3D volume reconstruction and several topotypic specimens. The microCT analysis revealed a considerable number of fossil concretions of U. maracoani , with both males and females likely sharing the same burrow. This is the first fossil record of a male fiddler crab with a female inside a burrow, where mating usually takes place. This mating style is common to almost all extant American fiddler crabs. • This is the first complete and detailed taxonomic review of Uca maracoani antiqua. • Uca maracoani morphology persisted unchanged for at least 16 Ma. • Evolutionary stasis may be not uncommon among fiddler crabs. [ABSTRACT FROM AUTHOR]

This study reports a three-dimensional fossil skull of a Tetraodontidae that dates to the middle Miocene (Serravallian), which was recovered from a rock matrix from the Valiente Peninsula Formation in the Bocas del Toro Archipelago, Caribbean coast of Panama. The new species, † Lagocephalus striatus n. sp., is the first fossil species of Tetraodontidae described from the Proto-Caribbean/Central Western Atlantic. We used high-resolution micro-CT scans of fossil and extant species to identify morphological characters on the skull, including the neurocranium, oromandibular and opercular bones, hyoid arch, and pectoral girdle. Specimens of both extant and extinct species of similar size were compared for accurate identification. We assess the paleogeographic distribution of the pufferfish group in the Neogene of Tropical America after the complete formation of the Isthmus of Panama. [ABSTRACT FROM AUTHOR]