Morphological variation in the rangeomorph organism Fractofusus misrai from the Ediacaran of Newfoundland, Canada

• Published in: Geological Magazine
• Main Authors: Taylor, Rod S., Nicholls, Robert, Neville, Jenna M., McIlroy, Duncan
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2022
• Subjects: Newfoundland
• Online Access: http://dx.doi.org/10.1017/s0016756822000723; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756822000723

Abstract The Ediacaran rangeomorph Fractofusus misrai is the most common and best-preserved of the E Surface fossil assemblage in the Mistaken Point Ecological Reserve of southeastern Newfoundland, Canada. Fractofusus has been interpreted as a fusiform epifaunal soft-sediment recliner, and like other rangeomorphs it has a self-similar, fractal-like branching morphology. The rangeomorph branching of Fractofusus has been considered to be identical on the upper and lower surfaces; however, study of specimens with complex biostratinomic histories suggests clear differences between the upper and lower surfaces. The first-order branches grew downwards into the sediment from a high point near the midline but grew above the sediment–water interface at their lateral and distal margins. Our new three-dimensional appreciation of rangeomorph branching in Fractofusus explains many of the taphomorphs of Fractofusus including straight, curved, kinked and tousled forms. The three-dimensional morphology, mode of life, taphonomy and palaeoenvironmental interactions of F . misrai are discussed along with a new three-dimensional reconstruction.