Lethenia

History In 1880, the paleontologist Winkler, T.C. found a tooth cataloged as IRSNB P00717 which at the time was interpreted as a new species of shark of the genus Odontaspis, since the original fossil looked a lot like this genus, so it was named O. vandenbroecki. More than a century after the description of O. vandenbroecki, it was reclassified as a species of the genus Lamna, where its fossils resembled more "L. rupeliensis" and L. nasus, but later it was reclassified as belonging to the genus Isurolamna. This classification remained for more than a decade, until it was reclassified into its own genus, Lethenia, in 1999. After a little more than a decade, a fossil was found that was determined to belong to the genus Isurolamna, but its species was not known. In 2025, it was suggested as a new species of the genus Lethenia, then being named L. carranzaensis, differing from L. vanderbroecki by having two rhomboid triangular lateral cusps on the anterior, lateral, and posterior teeth, with complete cutting edges reaching the base of the crown, root lobes almost subrectangular, especially in anterior and anterolateral teeth, and straight lateral cusps. ==References==