Scott D. Evans

Highly regulated growth and development of the Ediacara macrofossil Dickinsonia costata

The Ediacara Biota represents the oldest fossil evidence for the appearance of animals but linking these taxa to specific clades has proved challenging. Dickinsonia is an abundant, apparently bilaterally symmetrical Ediacara fossil with uncertain affinities. We identified and measured key morphological features of over 900 specimens of Dickinsonia costata from the Ediacara Member, South Australia to characterize patterns in growth and morphology. Here we show that development in Dickinsonia costata was surprisingly highly regulated to maintain an ovoid shape via terminal addition and the predictable expansion of modules. This result, along with other characters found in Dickinsonia suggests that it does not belong within known animal groups, but that it utilized some of the developmental gene networks of bilaterians, a result predicted by gene sequencing of basal metazoans but previously unidentified in the fossil record. Dickinsonia thus represents an extinct clade located between sponges and the last common ancestor of Protostomes and Deuterostomes, and likely belongs within the Eumetazoa.

You can get anything you want from Alice's Restaurant Bed: exceptional preservation and an unusual fossil assemblage from a newly excavated bed (Ediacara Member, Nilpena, South Australia)

We present findings from the newly discovered fossiliferous bed, TB-ARB, from the Ediacara Member exposed at the National Heritage Site, Nilpena Station, west of the Flinders Ranges, South Australi...

Attenborites janeae: a new enigmatic organism from the Ediacara Member (Rawnsley Quartzite), South Australia

Attenborites janeae gen. et sp. nov., is a new enigmatic fossil from the Ediacara Member of the Rawnsley Quartzite, South Australia. Attenborites is a well-defined irregular oval to circular fossil...

Stuck in the mat: Obamus coronatus, a new benthic organism from the Ediacara Member, Rawnsley Quartzite, South Australia

ABSTRACTHere we describe a new fossil, Obamus coronatus gen. et sp. nov., from the Ediacara Member of the Rawnsley Quartzite. O. coronatus is preserved in negative hyporelief and is defined by an o...