Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 77. (Budapest 1985)
Kordos-Szakály, M. ; Kordos, L.: Morphotypes of Hungarian fossil Celtis (Urticales) stones
Fig. 1. Anatomy and measuring points of the Celtis stony endocarps: A = apex, B = basis, C = meridional circular suture, D = main crest, E = secondary crest, F = separation stump, G = canalis basale. Measured points: 1 = height, 2 = width, 3 = width at the main crest, 4 = half width Material For our investigations the carpological collections of the Botanical, Geological and Paleontological Departments of the Hungarian Natural History Museum as well as the remains of the Paleovertebrate Collection of the Hungarian Geological Institute were used. The material of these collections practically includes all the Celtis stones found in Hungary. During our work 5659 finds originating from approximately 43 layers of 17 localities were studied. Among them the number of measurable, i.e. at least 50% preserved, specimens was 874, which represents 15.4% of the whole material (Table 1). Anatomy of the Celtis stony endocarp Since up to the present no anatomical description of Celtis stones and the excellently fossilized stony endocarps has been given, it is advisable to fill this gap here —also for facilitating unambiguous identification (Fig. 1). The stony endocarp is the innermost layer (endocarpium) of the wall of the stone which, as a consequence of its still unknown highly resistant material composition, is much more resistant than the other stony seeds. Stony endocarp has a seemingly radial symmetry, however in reality it is divided into two hemispheres along a meridional circular suture, thus its symmetry is bilateral. Then stem of the stony endocarp is called its basis —it is the place of separation —while the opposite part is the "peak" (apex). The separation stump usually remains on the basis, on young specimens and in certain morphotypes it is elongated like a beak. At this same spot a sometimes open, sometimes locked canal (canalis basale) leads out from the inner cavity of the stony endocarp. Its inner initial part widens out like an asymmetrical cone.
