Modern and early Holocene mollusc fauna of the Ounianga lakes (northern Chad): implications for the palaeohydrology of the central Sahara

Abstract

The fresh and saline lakes of Ounianga Kebir and Serir in northeastern Chad are among the very few permanent aquatic
ecosystems currently existing in the hyper-arid core of the Sahara desert. The confirmed modern fauna of aquatic molluscs at
Ounianga comprises three widespread species (Melanoides tuberculata, Biomphalaria pfeifferi and Lymnaea natalensis), of which
only the first appears to maintain a thriving population. We recovered seven more species of gastropods, among which one is new to
science (Gabbiella ouniangaensis), and one bivalve species from early Holocene outcrops of diatomaceous limestone at Ounianga
Serir. All species except one are known to be commonly spread between lake and river systems by birds, and in its entirety this
species-rich fossil mollusc fauna of Ounianga Serir resembles that of other Saharan lake sites known to have been hydrologically
isolated during the early Holocene. The impoverished modern mollusc fauna, which lacks even the widespread and opportunistic
species Bulinus truncatus, may have become established relatively recently through new colonisation events, following eradication of
the early Holocene mollusc fauna during a later episode of high salinity or desiccation. Copyright # 2011 John Wiley Sons, Ltd.

• african humid period
• biogeography
• chad
• freshwater molluscs
• green sahara
• paleoclimatology
• qunianga
• zoochory

Resources

• Bocxlaer_etal_2011_Holocene_Mollusc_Qunianga_Chad_Palaeohydrology_Sahara.pdf
• http://onlinelibrary.wiley.com/doi/10.1002/jqs.1469/abstract

Bibliography

Bocxlaer B.V., Verschuren D., Schettler G., Kröpelin S. (2011): Modern and early Holocene mollusc fauna of the Ounianga lakes (northern Chad): implications for the palaeohydrology of the central Sahara. In: Journal of Quaternary Science 26: 433-447