共 4 条
Changes in the Shell Ornamentation of Conchostracans (Phyllopoda, Spinicaudata) at the Permian-Triassic Boundary: Case Studies from Eastern Europe, Kuznetsk Basin, and Verkhoyansk Region
被引:0
|作者:
Zharinova, V. V.
[1
,2
]
Silantiev, V. V.
[1
,3
]
机构:
[1] Kazan Fed Univ, Kazan 420008, Russia
[2] Russian Acad Sci, AN Severtsov Inst Ecol & Evolut, Moscow 119071, Russia
[3] Branch Kazan Fed Univ City Jizzakh, Jizzakh 130000, Uzbekistan
来源:
基金:
俄罗斯科学基金会;
关键词:
ornamentation;
fossil conchostracans;
Permian-Triassic boundary;
Spinicaudata;
CRUSTACEA-CONCHOSTRACA;
BRANCHIOPODA;
MICROSCULPTURE;
CLASSIFICATION;
DIPLOSTRACA;
D O I:
10.26907/2542-064X.2022.4.606-632
中图分类号:
O [数理科学和化学];
P [天文学、地球科学];
Q [生物科学];
N [自然科学总论];
学科分类号:
07 ;
0710 ;
09 ;
摘要:
This article sums up the results of our study on shell ornamentation of 13 conchostracan species. Their fossil remains were sampled from the Middle and Upper Permian, Induan, and Olenekian (Lower Triassic) deposits of different zoogeographical provinces. Careful examination of the samples revealed different ornamentation patterns of the outer and middle shell layers: the linear elements of the two layers are set in different directions and together create an intersected structure stiffening the shell. Considering the differences in the number and arrangement of ornamental elements on the growth bands and the shells, three types of ornamentation were singled out: simple (one ornamental element), transitional (two or-namental elements alternating on the shell surface), and complex (more than two ornamental elements arranged in a complex pattern). It was concluded that the combination and arrangement of ornamental elements should be regarded as a valid diagnostic feature of fossil conchostracans at the species and genus ranks. Interestingly, the ornamentation patterns of conchostracans tend to become more complex with time: the shells of Late Permian conchostracans have more twisted ornamentation than Middle Permian ones, but it is less complex than that of Olenekian conchostracans; accordingly, the ornamentation of Early Induan conchostracans is simpler than that of Late Permian and Olenekian ones. This can be ex-plained by the fact that the most opportunistic eurytopic species were more likely to survive in the early phases of the biota recovery after the Great Permian Extinction.
引用
收藏
页码:606 / 632
页数:27
相关论文