TY - JOUR

T1 - The ecology of Dickinsonia on tidal flats

AU - Sozonov, N. G.

AU - Bobkov, N. I.

AU - Mitchell, E. G.

AU - Kolesnikov, A. V.

AU - Grazhdankin, D. V.

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Specimens of Dickinsonia from the Central Urals are characterised by clear bilateral symmetry. Taking into account observations from Australian specimens, we consider that the so called 'glide reflection symmetry' in these fossils is a taphonomic phenomenon. The size frequency distribution plot shows the predominance of smaller individuals in the studied population of Dickinsonia from the Central Urals. Assuming that the age of an individual is manifested in the body size, there is a significant predominance of juvenile individuals in the population. Three possible scenarios can be envisaged: (i) the population has a large number of juvenile individuals as the result of high survivorship rate in the intertidal zone; (ii) the population teems with juvenile forms because it is buried immediately after hatching; (iii) assuming that Dickinsonia was an actively motile organisms, that abundance of juvenile individuals could be explained by their inability to escape burial (although it is difficult to imagine that some of the mature individuals are buried with signs of escape behaviour); and (iv) the population could be interpreted as a fossilised 'nesting ground' for Dickinsonia in the intertidal zone where juvenile forms underwent maturation before migrating back to the subtidal zone. The study population can be characterised as expanding or stable; therefore, the intertidal setting can be described as favourable for these organisms.

AB - Specimens of Dickinsonia from the Central Urals are characterised by clear bilateral symmetry. Taking into account observations from Australian specimens, we consider that the so called 'glide reflection symmetry' in these fossils is a taphonomic phenomenon. The size frequency distribution plot shows the predominance of smaller individuals in the studied population of Dickinsonia from the Central Urals. Assuming that the age of an individual is manifested in the body size, there is a significant predominance of juvenile individuals in the population. Three possible scenarios can be envisaged: (i) the population has a large number of juvenile individuals as the result of high survivorship rate in the intertidal zone; (ii) the population teems with juvenile forms because it is buried immediately after hatching; (iii) assuming that Dickinsonia was an actively motile organisms, that abundance of juvenile individuals could be explained by their inability to escape burial (although it is difficult to imagine that some of the mature individuals are buried with signs of escape behaviour); and (iv) the population could be interpreted as a fossilised 'nesting ground' for Dickinsonia in the intertidal zone where juvenile forms underwent maturation before migrating back to the subtidal zone. The study population can be characterised as expanding or stable; therefore, the intertidal setting can be described as favourable for these organisms.

KW - Central Urals

KW - Dickinsonia

KW - Ediacaran

KW - Russia

KW - Tidal-flat

KW - AFFINITY

UR - http://www.scopus.com/inward/record.url?scp=85076049145&partnerID=8YFLogxK

U2 - 10.3989/egeol.43587.571

DO - 10.3989/egeol.43587.571

M3 - Article

AN - SCOPUS:85076049145

VL - 75

JO - Estudios Geologicos

JF - Estudios Geologicos

SN - 0367-0449

IS - 2

M1 - e116

ER -