The Holocene palaeo-lake at Tayma hosts a unique association of athalassic marine microfauna. The formaniferal taxa identified in the deposits of the former inland lake are usually found in marginal marine environments, but have been introduced by migratory birds, adapted well to the saline continental waters and started to thrive due to a low level of competition. In a paper published in the current issue of the Journal of Foraminiferal Research, Anna Pint and colleagues present details on the species occurrence and test anomalies in foraminifera as well as the distribution of sieve pore shapes in the carapaces of ostracoda. Based on a comparison with comparable assemblages in marginal marine environments, it is suggested that that a combination of low diversity, exclusively marginal marine taxa, combined with occurrences of test anomalies >10% can be used to recognize athalassic saline waters in the fossil record.
Pint, A., Engel, M., Melzer, S., Frenzel, P., Plessen, B., Brückner, H., 2017. How to discriminate athalassic and marginal marine microfaunas? Foraminifera and other fossils from an early Holocene continental lake in northern Saudi Arabia. Journal of Foraminiferal Research 47, 175-187.