Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 64. (Budapest 1972)
Jánossy, D.: Middle Pliocene microvertebrate fauna from the Osztramos Loc. 1. (Northern Hungary)
The mandibles are all incomplete, either without incisor, or without ascending ramus. Only two specimens are convenient for taking measurements: the length of the mandibles from the posterior margin of the incisor to the posterior point of the condyloid process (on the inner side) is 11.4 mm and 11.8 mm, respectively. The height of the mandibles (4 specimens, measured on the inner side below ÄLJ ranges between 2.5-2.9 mm. The coronoid process is in the average higher and broader than that of A. oligodon (height of processus coronoideus 6.6; 6.8 and 7.2 mm). As follows from the measurements given below, the first lower molar (M x , with a slight outer cingulum) is longer (3.1-3.4 mm) and in the average slenderer (1.35-1.75) than in the Polgárdi species. The scatter diagram (see Text figure 4), Fig. 4. Scatter diagram showing length and width of M t of Amblycoptus. — 1. Amblycoptus oligodon KORMOS, Polgárdi; 2. Amblycoptus topali n. sp., Osztramos, loc. 1. showing the differences of the ratio of length and width of this tooth in the two forms of Amblycojrtiis, is the best proof in my opinion of the taxonomical distinctness of the Osztramos-form. In connection with the slender form of the first molar, the trigonid and talonid are more elongated and the protoconid-metaconid as well as the hypoconid-entoconid nearer to each other. This is a very interesting negative allometrical feature of evolution in this tooth against the Polgárdi-form. The relative reduction of the frontal teeth (except for the ,,large" incisor) and the posterior teeth of the tooth-row may be shown by the measurements of the different elements. (See tables) The other peculiar features of the genus Amblycojrtus (discussed in detail by KORMOS, 1926), e.g. the form and size of the upper and low r er incisors as well as the form of the condyloid process, etc., agree with those of the Polgárdi-form.
