Is that the Neanderthal spelling?
I believe our cousins across the pond spell it that way.
The writer has been trying harder, but has been really busy; less errors, but fewer time to work on spelling skills.
I’m surprised no one has commented (that I saw) about the completely correct spelling in the topic title, “Neandertal” (spelled as it’s pronounced, I guess the bullheaded incorrect limey “NeanderTHal” version is dying off).
When the first discovery was made on September 4, 1856, in the Neander Valley, the German spelling of "valley" was thal. Later a spelling reform changed the "th" to a "t" in that and other words, but the "Neanderthal" spelling had become well-known internationally by then.
There is an excellent recent book published by Routledge (ISBN 978-0-415-42520-9), entitled The Neanderthals, by Friedemann Schrenk and Stephanie Mu+ller (that's "u" umlaut), translated by Phyllis G. Jestice. The German version uses the spelling "Neandertal." The original was published in 2005 and the translation in 2009.
The Neander valley is named for a 17th-century theologian and hymn-writer named Joachim Neumann, who translated his name into Greek as "Neander" (from the Greek roots for "new" and "man").