Revealing rangeomorph species characters using spatial analyses
Accepted version
Peer-reviewed
Repository URI
Repository DOI
Change log
Authors
Abstract
Rangeomorphs dominate the Ediacaran Avalonian macrofossil assemblages of Charnwood Forest, UK (~562Ma). However, their unfamiliar fractal architecture makes distinguishing phylogenetically reliable characters from intraspecific features difficult. Fortunately, spatial analysis of large in-situ populations offers an independent means of assessing their taxonomy. Populations of a single biological species are likely to exhibit similar spatial distributions due to their shared responses to the biological and ecological processes acting upon them. As such, spatial analyses can be used to interrogate which are the most taxonomically deductive characters in similar species. We used Random Labelling Analyses to investigate the presence/absence of characters of Primocandelabrum boyntoni, P. aethelfalaedia and P. aelfwynnia on the North Quarry ’B’ surface. The resultant spatial distributions were compared to observed characters using goodness-of-fit tests to determine which characters were associated with unique populations, and which were found across multiple populations. We found that P. boyntoni and P. aelfwynnia had statistically indistinguishable character distributions, suggesting that they represent a single biological species, and that they exhibited significantly different distributions to P. aethelfalaedia, suggesting that there are two (rather than three) Primocandelabrum species present on the B surface. Furthermore, we found that the distribution of Concealed versus Unconcealed 1st order branches across all specimens exhibited significantly different, density-dependant behaviour, with Unconcealed branching occurring in areas of higher density populations, and Concealed branching occurring in the lower Primocandelabrum density areas. We speculate that unconcealed branches may have been a response to the reduced availability of resources in higher density areas, implying rangeomorphs were capable of ecophenotypic responses.
Description
Keywords
Journal Title
Conference Name
Journal ISSN
1480-3313