Protornoceras polonicum Dybczyński, 1913
Sugerowana cytacja: Dzik, J 2015. Protornoceras polonicum Dybczyński 1913. Ikonoteka (http://ikonoteka.paleo.pan.pl/xwiki/bin/view/Species/Protornoceras+polonicum+)
 Protornoceras polonicum; growth lines, sutures and outline of the shell. Diagnoza Open umbilicus of diameter about one tenth of that of mature conch; subtrapezoidal cross section of the whorl; rounded auricles of the aperture. Porównanie Similarly to other species of Protornoceras, the suture is very variable, especially in respect to concavity of the flank lobe, even within the same specimen. Width of the umbo seems to be of a higher taxonomic value, although it is variable, too (note that all earlier illustrated specimens are pyritic internal moulds). Several species proposed for specimens from Sieklucki’s brickpit , including P. siemiradzkii, P. bilobatiforme, P. kielcense, P. ornatum, and P. zuberi, Gomi-re-monomeroceras (Tornoceras) genulobatum planum, G. (T.) planilobum, G. (T.) planilobum angulatolobatum, G. (T.) planilobum avaricatum, and G. (T.) dorsatum, may belong here. The holotype of P. polonicum is a juvenile specimen with not fully developed suture. Autekologia Występowanie geograficzne Kowala and Łagów Słupecka 73 (sample ŁSł73-4); reworked at Sieklucki’s brickpit in Kielce. Zasięg czasowy Mid C. marginifera Zone. Materiały muzealne ZPAL: 33 specimens. Literatura Dzik, J. 2006. The Famennian "Golden Age" of conodonts and ammonoids in the Polish part of the Variscan sea. Palaeontologia Polonica 63, 1-359. |
|
