Guettardiscyphia zitti sp. n. – a remarkable hexactinellid sponge from the Lower Turonian of the Bohemian Cretaceous Basin

Abstract

1 Czech Geo log i cal Sur vey, Klárov 3, 118 21 Prague 1, Czech Re pub lic Vodrážka, R., 2017. Guettardiscyphia zitti sp. n. -a re mark able hexactinellid sponge from the Lower Turonian of the Bo hemian Cre ta ceous Ba sin. Geo log i cal Quar terly, 61 (3): 632-640, doi: 10.7306/gq.1373 This pa per de scribes a new hexactinosidan hexactinellid Guettardiscyphia zitti sp. n. on the ba sis of a de tailed study of 279 spec i mens from 12 lo cal i ties in the south ern part of the Bo he mian Cre ta ceous Ba sin. All the stud ied ma te rial co mes from the basal Bílá Hora For ma tion (Lower Turonian). The ge ol ogy and palae on tol ogy of the sponge-bear ing strata at stud ied lo cations ex hibit iden ti cal palaeoenvironmental set tings: 1 -transgressive char ac ter of sed i ments with low sed i men ta tion rates, 2 -pres ence of sub ma rine swells formed by crys tal line base ment, 3 -hemipelagic sed i men ta tion be low the storm-wave base, and 4 -the pres ence of pro lif er at ing di verse sponge fau nas with sub or di nate ac com pa ny ing macrofaunal re mains.