Diagnoza

The first coil is convex and an edge, located roughly in the middle of the turn begins on the second one. In the course of ontogeny, it is strengthened into a powerful keel. The adapical area of ​​the edge is beveled, the abapical area is approximately vertical. Both are covered with spiral ribs: adapical approx. 5, abapical up to suture 3–4. The spiral ribs are initially wider than the separating furrows, on the last coil they are narrower. Between these strong spiral ribs there are several spiral striae on the last coil. The keel also has two swellings on the last coil. There is a second keel in the seam, visible only on the last coil. It is followed by at least 7 strong spiral ribs on the convex base, between which a weaker one can be formed. Adults form a flat spread wing. Both keels cross over the wing without weakening and diverge clearly on it. Adapically, a short wing extension extends to the middle of the previous turn. The inner lip of the aperture is convex, its columellar part is concave.

Porównanie

Similar M. camelus Piette, 1855  has only one distinct spiral rib between the two keels, the early coils are much slimmer and fewer spiral ribs are formed on the base. M. balanus (Eudes-Deslongchamps, 1843) has much slimmer and more keeled early coils, on later coils the adapical keel is more pronounced and the base has fewer and equally strong spiral ribs. Rostellaria cirrus Eudes-Deslongchamps, 1843 has slimmer early coils, the last coil is broadened, the curvature of the coils is clearer and the spiral ribbing is more even. Chenopus (Malaptera) difformis Cossmann, 1885 differs in the stronger keel of the penultimate coil and the weaker and more numerous spiral ribs.

Autekologia

Występowanie geograficzne

Only in type locality

Zasięg czasowy

Mid Jurassic

Materiały muzealne

5 specimens from Balin (NHMW 1855/0011/0012a-c; NHMW 1853/0038/0074;  NHMW 1853/0038/007).

Literatura

Gründel, J. 2012. Neubearbeitung der von Laube 1867 beschriebenen Gastropoden fauna aus dem mittleren Jura von Balin/Polen. Annalen des Naturhistorischen Museums in Wien. Serie A, 114, 193–288.

Laube, G. C. 1867. Die Gastropoden des braunen Jura von Balin. Denkschriften der kaiserlichen Akademie der Wissenschaften, 28, 1–28.