Except it isn't an elementary particle at all. If you take the trouble to read just the abstract of the article, it is clear enough that what was observed wasn't a Majorana neutrino, but a collective state in a superconductor. That's cool, and it was quite challenging to create such a composite system that models a Majorana fermion, and it probably satisfies the equations to first order, but it isn't a new particle in the standard sense. Not in the sense that a proton or a tau is a particle (and a fermion).
If neutrinos are Majorana particles, then they are their own anti-particles. Since they're so hard to detect, it hasn't been actually proven that the neutrino and the anti-neutrino are distinct, so Majorana's proposition is still an open question. Despite what Jessica Orwig at Business Insider implies in the rather muddled article.
To be fair, the experimenters probably made the comparison themselves, and expected that other people would know the difference.