Substrate type and palaeodepth do not affect the Middle Jurassic taxonomic diversity of crinoids

PeerJ

article

Mariusz A. Salamon¹  Anna Feldman-Olszewska²  Sreepat Jain³  Bruno B.M. Ferré⁴  Karolina Paszcza⁵  Bartosz J. Płachno⁶ 

[1] Faculty of Natural Science, University of Silesia in Katowice;Polish Geological Institute - National Research Institute;Department of Applied Geology, School of Applied Natural Sciences, Adama Science and Technology University;Saint Étienne du Rouvray;Faculty of Natural Sciences, University of Silesie in Katowice;Faculty of Biology, Institute of Botany, Jagiellonian University in Kraków

关键词: Echinoderms;    Crinoids;    Jurassic;    Bathonian;    Callovian;    Poland;    Boreholes;   

DOI  :  10.7717/peerj.12017

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Crinoids are largely considered as good indicators for determining environmental conditions. They are robust proxies for inferring changes in salinity and sedimentation rate and for inferring substrate type. Some crinoid groups (e.g., certain comatulids, cyrtocrinids, millericrinids) have a depth preference, thus, making them useful for palaeodepth estimation. The hypotheses that crinoid distribution is substrate-dependent (rock type) or palaeodepth-dependent is tested here based on (a) archival Bathonian-Callovian (Middle Jurassic) crinoid occurrences from Poland and (b) newer finds from five boreholes from eastern Poland. Qualitative data suggests that isocrinids and cyclocrinids occur in both carbonate and siliciclastic rocks. The cyrtocrinids and roveacrinids occur within carbonate rocks, whereas the comatulids are exclusive to siliciclastics. In terms of palaeodepth, most crinoid groups dominate in shallow environments with the sole exception of cyrtocrinids, that are ubiquitous and occur in both shallow (near shore and shallow marine) and slightly deeper (deeper sublittoral to open shelf) settings. The occurrences of the cosmopolitan taxa, Chariocrinus andreae and Balanocrinus subteres (isocrinids), is independent of both substrate type and palaeodepth. Quantitative analyses (Analysis Of Variance; ANOVA) based on substrate type, i.e., substrate-dependency (claystones, sandstones and limestones), and palaeodepth i.e., palaeodepth-dependency (near shore, shallow-marine, mid-ramp and offshore), corroborate qualitative results. Statistical analysis suggest that the distribution of crinoids shows a strong substrate-dependency but not for palaeodepth, although very weak significance (low p value) is noted for near shore and shallow marine settings and crinoid distribution.

【 授权许可】

CC BY