IX. Description of the skull and teeth of the placodus laticeps, owen, with indications of other new species of placodus, and evidence of the saurian nature of that genus

Abstract

Count Münster, in the year 1830, obtained two specimens of portions of the upper jaw with the palate and teeth, of a vertebrate fossil, from the Muschelkalk member of the Triassic system near Bayreuth, which he described and figured in a brochure, entitled 44 "Fossile Fischzähne von Bayreuth,” referring the specimens to the class of Fishes. They were chiefly remarkable for the large size, and especially the breadth and shortness, of the crowns of the teeth. Professor Agassiz, in the 'Part’ of his great work on Fossil Fishes, which appeared in 1833, and formed the commencement of the second volume, accepted Count Münster’s determination of the foregoing fossils, referred them to the Pycnodont family of the Ganoid order of his System of Ichthyology, and founded on them a genus which he called Placodus , a term significant of the broad flat teeth of such supposed fishes. The generic character given by Professor Agassiz is as follows: —"Dents polygones, à angles arrondis, dont la surface est aplatée et entièrement lisse;” and he adds, “Rangé par induction dans l’ordre des Ganoïdes; car je n’ai jamais vu les écailles d’aucun poisson de ce genre ?” Of this genus he defines two species:— 1. Placodus impressus , Ag.; characterized by a depression on the middle of the crown of the tooth, from the triassic formation called 'gres bigarré,’ at Deux Ponts. 2. Placodus gigas , Ag.; characterized by the flat crown of the teeth: from the Muschelkalk, Bayreuth. This species is founded on the specimens originally described by Count Münster.