Shark bites
EE: I'm not convinced. The word etrange is an adjective, directly following the noun (requin) that it modifies. The french is clear "unknown shark" (and the French language does not tend to suffer from the zillions of grammatical 'exceptions to the rule' that we live with in English).
The original French is written in the singular 'un requin etrange' (an unknown shark). However, it is also possible that the author intended this to be read along the lines of 'an unknown shark species. In this case, probably not because there is a mystery species out there, but more likely because there was not sufficiently strong evidence to implicate one species or another...
Enough on the sharks. Back to the fascinating technical theorizing that draws this SLF (and pilot wannabee) to PPRUNE every day....