[EN]A redescription of the holotype (monotype) of Asturichelys multicostatus existing at the Museum of Natural History of Madrid is made in this paper. This specime was found in the continental Ludian of Oviedo (Spain) in 1926, and was first and wrongly described by Bergounioux in 1957. According to this new diagnosis, the specimen has a continuous series of 10 neural plates under the 4 first vertebral scutes, and 10 costal plates. The osseous condition under the 5th vertebral scute is unknown. The plastron, which is only partially known by its inner cast, is very simple and without mesoplastrons. Such a number of plates in the carapace indicates a primite feature, while the simplicity of the plastron points to a more developped character. Due to these contradictory facts, the inclusion of this specimen in a definitive family is not possible with present data for the time being, Therefore, the classification of this chelonian as an incertae familiae is proposed, although there is the possibility that the Asturichelys multicostatus represents one of the last members of a new family.

[ES]Redescripci?n de Asturichelys multicostatus a partir de la observaci?n directa del holotipo (monotipo) descrito por Bergounioux en 1957, que se conserva en el Museo Nacional de Ciencias Naturales de Madrid. Procede del Ludiense continental de Oviedo, donde se extrajo en 1926. Seg?n la nueva diagnosis, el ejemplar tiene 10 placas neurales en serie ininterrumpida debajo de los 4 primeros escudos vertebrales y 10 placas costales. No se conoce la disposici?n ?sea debajo del 5? escudo vertebral. El peto -parcialmente conocido por su molde interno- es muy simple, sin mesoplastrones. Tal n?mero de placas en el espaldar es un car?cter muy arcaico. Junto a ello, el peto simplificado representa un car?cter moderno. De la combinaci?n de ambos resulta una clasificaci?n familiar no posible con los datos actualmente conocidos. Por ello se ha incluido como incertae familiae, aunque cabe la posibilidad de que realmente corresponda a una nueva familia, de la que ser?a un representante p?stumo.