Longiproetus, CAVET et PILLET, 1958

Budil, Petr & Mergl, Michal, 2019, Trilobite Assemblage Of Calceola - Bearing Beds In Acanthopyge Limestone (Choteč Formation, Middle Devonian, Eifelian, Prague Basin, The Czech Republic), Fossil Imprint 75 (1), pp. 79-91 : 83-85

Longiproetus ? sp.

Text-fig. 4a–b,?c

M a t e r i a l. One pygidium (internal mould and its counterpart), isolated free cheek (?).

R e m a r k s. One isolated pygidium apparently belongs to the subfamily Proetinae – it is prominently vaulted, with a semi-elliptical outline, wide, robust axis and well developed, moderately vaulted posterior margin with shallow, wide border furrow. However, its generic affiliation is uncertain. The above-discussed features, together with well-developed axial rings and deep pleural furrows on lateral pygidial lobes preclude its determination as Orbitoproetus , commonly occurring in Acanthopyge Limestone in the Kobyla area. An affiliation to Longiproetus ? sp. seems to be most suitable (note also a similar number of axial rings – at least 7, plus short terminal part, for Longiproetus 8(7) axial rings is a diagnostic feature). From Erbenites PŘIBYL, 1964 , typical for this part of Acanthopyge Limestone , a different number of axial rings (only 4, plus long terminal part in Erbenites ), wider and deeper pleural furrows and different vaulting of pygidium with much deeper and wider border furrow clearly distinguish the described pygidium. From Coniproetus (Tropiconiproetus) ŠNAJDR, 1980 , the discussed pygidium differs especially by much deeper and wider pleural furrows. With some uncertainty, an incomplete isolated free cheek figured in Text-fig. 4c is also affiliated to Longiproetus .