Comparative data show a strong correlation between projecting nostrils & large paranasal sinuses. This is extreme in elephants, but is also seen in suids & tapirids. In Homo, it's obvious in H.heidelbergensis-neanderthalensis. Some neandertals had traces of cattails on their tools, and traces of waterlily roots in their dental calculus (H.erectus at GBY also dived for waterlily roots, N.Goren-Inbar cs 2016 Internet Archaeol doi 10.11141/ia.37.1), their fossils are found in river valleys (wetlands, oxbow lakes, reedbeds, beaver ponds etc.) or at sea-coasts: did neandertals seasonally follow the river to the sea (cf Gibraltar & northern Mediterranean coastal fossils)? e.g. Marc Verhaegen & Peter Rhys Evans 2015 "Sinuses and flotation: Does the Aquatic Ape Theory hold water?" doi 10.13140/RG.2.1.4293.7688, google researchGate marc verhaegen.
