The Ediacara Biota represent a turning point in the evolution of life on Earth, signifying the transition from single celled organisms to complex, community forming macrobiota. The exceptional fossil record of the soft-bodied Ediacara Biota provides critical insight into the nature of this transition and into ecosystem dynamics leading up to the so-called “Cambrian Explosion”. However, the preservation of non-biomineralizing organisms in a diversity of lithologies goes hand-in-hand with considerable taphonomic complexity that often shrouds true ecological and biological signatures. We address the nature of this taphonomic complexity within the fossiliferous sandstones of the Ediacara Member in South Australia. Utilizing the most data-rich and well-preserved outcropping of the Ediacara Member, the Nilpena Station National Heritage Ediacara Fossil Site, we conduct a focused, taxon-level taphonomic characterization of the tubular organism Funisia dorothea. Funisia is the most abundant body fossil in the Ediacara Member, making its taphonomic characterization essential to the accurate interpretation of regional paleobiology and paleoecology. We identify two primary modes of Funisia population structure, cluster-type and surface-type packages, each of which exhibit distinct suites of taphonomic variation in individual Funisia. Within the two package types, four preservational modes of Funisia are identified: convex external molds, concave external molds, convex internal molds, and concave internal molds. Among macrofossils at Nilpena, this tiered preservational complexity is unique to Funisia; its systematic classification elucidates population-level biostratinomy at Nilpena as well as aspects of Funisia’s paleobiology and autecology.

The earliest fossil evidence for complex, macroscopic, community forming organisms on Earth is preserved in the Ediacara biota (575—538 Ma). While placement of Ediacaran taxa within a phylogenetic framework is difficult due to their unique morphologies that are non-analogous to the definitive metazoans of the Phanerozoic, they can be categorized into grades based on body plan similarity, resulting in suites of morphologically similar, but not necessarily phylogenetically related, taxa known as morphogroups. The tubular morphogroup includes all macroscopic, metazoan-grade organisms with hollow and elongate morphologies and is one of the most commonly occurring Ediacaran morphogroups, suggesting that a tubular form was an advantageous morphology for early complex organisms. However, the nature of this advantage is unknown and untestable due to insufficient baseline understanding of the number of genera included in the morphogroup, their temporal ranges, as well as their paleobiological traits and paleoecological strategies. This dissertation develops a foundational understanding of these questions pertaining to the tubular morphogroup through database generation and analysis, detailed taphonomic investigation, and analysis of growth strategies. Synthesis of the global record of the Ediacaran tubular morphogroup demonstrates that they are the most diverse Ediacaran morphogroup and were key components of Ediacaran ecosystems for ~20 million years longer than was previously appreciated. Detailed taphonomic investigation of the tubular organism Aulozoon soliorum from the Ediacara Member of South Australia provides novel insight into the morphology, biomaterials, and paleoecology of this taxon as well as develops a methodology for distinguishing between true morphological features and taphonomically-derived features that that can be leveraged for investigation of other tubular taxa. Study of the growth strategies of the tubular organism Funisia dorothea from the Ediacara Member of South Australia demonstrates that, despite a broadly simple form, Funisia’s growth was highly regulated. Additionally, comparison of Funisia’s growth strategies with another tubular organism, Wutubus annularis, reveals that shared morphology of tubular organisms does not beget developmental or paleoecological similarity. Ultimately, this research develops understanding of what genera, paleoecological strategies, and paleobiological traits are encompassed by the tubular morphogroup and provides novel frameworks for the identification of paleobiologically and paleoecologically meaningful characteristics of individual tubular genera.