Comment on: Tang et al. [2019]: A problematic animal fossil from the early Cambrian Hetang Formation, South China

Slater, Ben J.; Budd, Graham E.

doi:10.1017/jpa.2019.54

Cited by 4 publications

(15 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

mentioning

confidence: 95%

“…A third difficulty with Slater and Budd's (2019) argument pertains to their suggestion that the biological structures we identified as crossbars and outgrowths in Cambrowania were instead taphonomic artifacts. In particular, Slater and Budd (2019) illustrated Cambrian Leiosphaeridia specimens with lanceolate folds to suggest that these might be the double crossbars and blades we found in Cambrowania. However, Slater and Budd's (2019) claimed similarity is superficial at best because compressed vesicles of Leiosphaeridia generally have concentric marginal folds in addition to lanceolate ones ( Fig.…”

mentioning

confidence: 95%

“…The first difficulty with Slater and Budd's (2019) interpretation is that Cambrowania (∼5 mm in diameter; Fig. 1.1) is at least an order of magnitude (three orders of magnitude in volume) larger than Leiosphaeridia (typically <200 µm in diameter; Fig.…”

mentioning

confidence: 99%

“…1.2) (Jankauskas et al, 1989;Butterfield et al, 1994). Although rare leiospheres can reach as much as 1 mm in diameter (Slater and Budd, 2019), they are still significantly smaller than Cambrowania.…”

mentioning

confidence: 99%

“…1.1). An additional difficulty with Slater and Budd's (2019) suggestion that the crossbars in Cambrowania are better interpreted as pyritized folds in carbonaceous vesicles of Leiosphaeridia is that the crossbars in Cambrowania are thin cylindrical structures (see figure 6 in Tang et al, 2019), whereas the folds of Leiosphaeridia are generally spindle-shaped and do not form cylinders. Yet another problem with Slater and Budd's (2019) *Corresponding author Journal of Paleontology 93(6):1279-1282 1280 assertion about the equivalence of crossbars and folds is that the number and size of lanceolate folds on a Leiosphaeridia (or any other acritarch) vesicle are limited by the surface area of a sphere relative to that of a compressed disc.…”

mentioning

confidence: 99%

See 4 more Smart Citations

A problematic animal fossil from the early Cambrian Hetang Formation, South China—A reply

Qing

Hu²,

Xie

et al. 2019

J. Paleontol.

View full text Add to dashboard Cite

We recently reported Cambrowania ovata Tang and Xiao in Tang et al., 2019, from the early Cambrian Hetang Formation in South China and interpreted it as a problematic animal fossil, possibly related to either sponges or bivalved arthropods (Tang et al., 2019). Slater and Budd (2019) contested our taxonomic identification and phylogenetic interpretation; instead, they claimed that Cambrowania ovata is a large acritarch referable to morphotaxon Leiosphaeridia Eisenack, 1958, and thus is not an animal. Here we refute their criticisms, clarify the differences between Cambrowania and Leiosphaeridia and other acritarchs, and reiterate why an animal affinity for Cambrowania cannot be ruled out.

show abstract

mentioning

confidence: 95%

mentioning

confidence: 95%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

A problematic animal fossil from the early Cambrian Hetang Formation, South China—A reply

Qing

Hu²,

Xie

et al. 2019

J. Paleontol.

View full text Add to dashboard Cite

show abstract

Morphometric analysis ofSkiagia-plexus acritarchs from the early Cambrian of North Greenland: toward a meaningful evaluation of phenotypic plasticity

2022

Self Cite

View full text Add to dashboard Cite

The Cambrian evolutionary radiations are marked by spectacular biotic turnovers and the establishment of increasingly tiered food chains. At the base of these food chains are primary producers, which in the Cambrian fossil record are chiefly represented among organic-walled microfossils. The majority of these microfossil remains have traditionally been attributed to an informal category of incertae sedis called “acritarchs,” based entirely on form taxonomy. Acritarch form taxa have been intensely used for biostratigraphy and in large-scale studies of phytoplankton diversity. However, both prospects have been challenged by cases of taxonomic inconsistencies and oversplitting arising from the large phenotypic plasticity seen among these microfossils. The acritarch form genus Skiagia stands as an ideal case study to explore these taxonomic challenges, because it encompasses a number of form species widely used in lower Cambrian biostratigraphy. Moreover, subtle morphological differences among Skiagia species were suggested to underlie key evolutionary innovations toward complex reproductive strategies. Here we apply a multivariate morphometric approach to investigate the morphological variation of Skiagia-plexus acritarchs using an assemblage sourced from the Buen Formation (Cambrian Series 2, Stages 3–4) of North Greenland. Our analysis showed that the species-level classification of Skiagia discretizes a continuous spectrum of morphologies. While these findings bring important taxonomic and biostratigraphic hurdles to light, the unequal frequency distribution of life cycle stages among Skiagia species suggests that certain elements of phytoplankton paleobiology are nonetheless captured by Skiagia form taxonomy. These results demonstrate the value of using morphometric tools to explore acritarch phenotypic plasticity and its potential ontogenetic and paleoecological drivers in Cambrian ecosystems.

show abstract

Late Ediacaran organic microfossils from Finland

Willman

Slater

2021

Geol. Mag.

Self Cite

View full text Add to dashboard Cite

Here we present a detailed accounting of organic microfossils from late Ediacaran sediments of Finland, from the island of Hailuoto (northwest Finnish coast), and the Saarijärvi meteorite impact structure (~170 km northeast of Hailuoto, mainland Finland). Fossils were recovered from fine-grained thermally immature mudstones and siltstones and are preserved in exquisite detail. The majority of recovered forms are sourced from filamentous prokaryotic and protistan-grade organisms forming interwoven microbial mats. Flattened Nostoc-ball-like masses of bundled Siphonophycus filaments are abundant, alongside Rugosoopsis and Palaeolyngbya of probable cyanobacterial origin. Acritarchs include Chuaria, Leiosphaeridia, Symplassosphaeridium and Synsphaeridium. Significantly, rare spine-shaped sclerites of bilaterian origin were recovered, providing new evidence for a nascent bilaterian fauna in the terminal Ediacaran. These findings offer a direct body-fossil insight into Ediacaran mat-forming microbial communities, and demonstrate that alongside trace fossils, detection of a bilaterian fauna prior to the Cambrian might also be sought among the emerging record of small carbonaceous fossils (SCFs).

show abstract

Comment on: Tang et al. [2019]: A problematic animal fossil from the early Cambrian Hetang Formation, South China

Cited by 4 publications

References 18 publications

A problematic animal fossil from the early Cambrian Hetang Formation, South China—A reply

A problematic animal fossil from the early Cambrian Hetang Formation, South China—A reply

Morphometric analysis ofSkiagia-plexus acritarchs from the early Cambrian of North Greenland: toward a meaningful evaluation of phenotypic plasticity

Late Ediacaran organic microfossils from Finland

Contact Info

Product

Resources

About