Final answer:
The question regarding the normal range of tongue endurance in seconds appears to be based on a misunderstanding, as typical endurance is not solely measured in seconds and the provided references do not contain relevant information.
Step-by-step explanation:
The normal range of tongue endurance is not specifically mentioned in terms of seconds. The provided reference mentioning an average time of forty-five days by Willcocks in 1913 does not seem to correlate with the standard measure of endurance in seconds. The duration noted by Barois in 2010 also does not provide a clear answer to the question of tongue endurance in seconds. It is possible that there has been a misunderstanding in the question as the typical measurements of endurance, especially in the context of tongue function, are usually conducted through different clinical assessments, not typically measured by the number of seconds alone.