The provenance and palaeobiology of a new multi-vaned, chambered frondose organism from the Ediacaran (later Neoproterozoic) of South Australia

Abstract

The new, large, frondose and stalked, Ediacaran (late Neoproterozoic) 'petalonamid' Pambikalbae hasenohrae gen. et sp. nov. is preserved in a three-dimensional manner within sandy channel fills occurring directly below the Ediacara Member of the Rawnsley Quartzite on the 'Nilpena' pastoral property at a western outlier of the Flinders Ranges, South Australia. Pambikalbae hasenohrae was made up of numerous chambered vanes supported by a tapering axial stem and an anchoring stalk. Chambers forming the vanes were commonly infilled with sediment, though variably flattened; groups of vanes representing individual specimens can extend as much as c. 3.7 cm deep through the hosting sandstone matrix. Several series of chambers present in each vane abut at zigzag sutures. Pambikalbae is clearly not a cnidarian sea pen, but nevertheless exhibits characteristics suggestive of an evolutionary grade comparable to that of known modern cnidarian divisions. Though the serial geometric configuration of its thin integument seems ideally suited to house symbiotic microbial photoautotrophs, our appraisal of the palaeoecology of Pambikalbae is supportive of its being a heterotrophic suspension feeder. Pambikalbae may plausibly be a highly derived hydrozoan, part of the ancestral stock of the Siphonophorida, or a sister group to the early Chondrophorina.

Chapter 68 Billy Springs glaciation, South Australia

“…The relatively extensive North America and Baltica measurements tabled in Torsvik et al (1996Torsvik et al ( , 2001 and McClausland et al (2007) may also be referenced relative to African data. Striking geological and palaeontological similarities between the Adelaide Rift Complex and northern Baltica during the Ediacaran are supportive of these regions then lying adjacent (Jenkins 2007;Jenkins & Nedin 2007).…”

Cambrian petalonamid Stromatoveris phylogenetically links Ediacaran biota to later animals

“…Pisani et al . ) (Buss & Seilacher ; Jenkins & Nedin ; Vickers‐Rich ; Brasier & Antcliffe ; Sperling & Vinther ; Dufour & McIlroy ). Within this cladistic framework (Fig.…”

“…), Pteridinium , Ernietta , Swartpuntia , Arborea (using the specimen classifications of the South Australian Museum which incorporate some specimens previously classified as Charniodiscus ; Laflamme et al . ), Pambikalbae (originally described as a member of Petalonamae; Jenkins & Nedin ) and Dickinsonia . These genera were selected because they represent intersecting sets of taxa previously suggested to fall within a single Ediacaran clade (Pflug ; Seilacher ; Jenkins & Nedin ; Dececchi et al .…”

“…However, Ediacaran macrofossils are generally preserved as comparatively uninformative surface impressions (moulds or casts). Consequently, hypothesized animal relationships (Buss & Seilacher ; Jenkins & Nedin ; Vickers‐Rich ; Brasier & Antcliffe ; Sperling & Vinther ; Meyer et al . ; Gold et al .…”

How well do fossil assemblages of the Ediacara Biota tell time?: REPLY

“…We included relatively common taxa, most of which occur at other Ediacara localities worldwide. Retallack claims that Pambikalbae (Jenkins and Nedin, 2007) is known from various facies in the Ediacara Member and should have been included. Apart from not being a Rangeomorph and considering that the type material comes from just one bed in a single location, it is impossible to describe this organism as being distributed in "various facies" (Retallack, 2014).…”