Recent biogenic traces from the coastal environments of the southern Red Sea coast of Saudi Arabia

Abstract

A neoichnological study was done at a site west of Abha on the southern Red Sea coast of Saudi Arabia. This area covers Wadi Hali and its surroundings (180 49′35.27″N: 410 22′44.23″E). The objective of the study is to document biogenic traces that occur in the upper intertidal ripple-marked sand flats and supratidal flats that include microbial mats, mud flats, and scattered patches of mangrove stands and their muddy environments. Based on morphological descriptions, four different kinds of burrows are identified and their fossil equivalents are Psilonichnus upsilon (burrow type 1), Cylindricum (burrow types 2 and 3), and Arenicolites (burrow type 4). Tracks of land hermit crabs Coenobita clypeatus are described as ichnospecies Coenobichnus currani. Gastropod grazing trails and their fossil equivalent Planolites is identified as well. Supratidal algal mats and their microscopic contents are presented. Fossil plant roots (rhizomes) are reported from a localized fluvial deposit from a dry channel (wadi). The morphology of the traces, trace maker, and ethology and the environmental setting indicate that the ichnofauna and botanical traces belong to the Psilonichnus ichnofacies.