Evolution of Holdfast Diversity and Attachment Strategies of Ediacaran Benthic Macroalgae

Xiaopeng Wang,Xunlai Yuan,Zhe Chen,Bin Wan,Chengguo Guan,Ke Pang,Mengyin Wu,Changtai Niu,Wentao Zheng

doi:10.3389/feart.2021.783427

Abstract

Holdfast morphologies and attachment strategies of benthic macroalgae are somewhat flexible and controlled by both the substrate condition and species. Six forms (tapered base, globose holdfast, composite globose holdfast, discoidal holdfast, rhizoids and horizontal rhizomes) of attachment structures of Ediacaran benthic macroalgae are recognized from the early Ediacaran Lantian biota and late Ediacaran Miaohe biota in South China based on functional morphology. Each form is considered either adapted to firm substrates that dominate the Precambrian seafloor, or soft substrates that are more common in the Phanerozoic. The results show a diversification in both holdfast morphology and attachment strategies of macroalgae during the Ediacaran Period. In the early Ediacaran Lantian biota, none of the benthic macroalgae is adapted to soft substrates, while in the late Ediacaran Miaohe biota, a considerable number (41%) of species are adapted to relatively soft substrates. This shift might be an adaptive response to the diversification of macroalgae and a changing substrate condition during the Ediacaran Period: the decline of microbial mats and increase of water content in the sediments in the Ediacaran.

Highlights

Benthic macroalgae are important components of modern and past ecosystems
This study focuses on the evolution of macroalgal holdfasts, attachment strategies and substrate conditions during the Ediacaran Period by examining Lagerstätten in South China: the early Ediacaran Lantian biota and the late Ediacaran Miaohe biota
We described holdfast morphologies of benthic macroalgae and analyzed their attachment strategies to understand the dynamic of substrate conditions in the early and late Ediacaran

Summary

INTRODUCTION

Benthic macroalgae are important components of modern and past ecosystems. They are more efficient primary producers than phytoplankton (Bunt, 1975) and provide food and habitats for many other organisms (e.g., Steneck et al, 2002). This study focuses on the evolution of macroalgal holdfasts, attachment strategies and substrate conditions during the Ediacaran Period by examining Lagerstätten in South China: the early Ediacaran Lantian biota and the late Ediacaran Miaohe biota. Both biotas are preserved in black shales, and they share comparable geological settings and depositional environments. The surface sediment of the Wenghui area was considered to be soupy (Wang and Wang, 2008)

MATERIAL AND METHODS

RESULTS AND DISCUSSION

DATA AVAILABILITY STATEMENT

CONCLUSION