The Super Mario Bros. Encyclopedia is a new book put out by Dark Horse, which comes with Nintendo's blessing. Nintendo even offered up an interview with Takashi Tezuka for the book. You would think all of this collaboration would mean the Super Mario Bros. Encyclopedia would be the be-all/end-all of Mario knowledge, but unfortunately, it seems Dark Horse got their details from a fan source.
The gang behind the Super Mario Wiki, a wealth of Mario knowledge pulled together by fans the world over, is claiming that the Super Mario Bros. Encyclopedia uses their content without citation. You can see some examples below.
For example, the guide's Super Mario Sunshine section names one of the enemy "Stoarin Stu'". This was a completely conjectural name made by the editor who created the enemy's wiki page (as the enemy is not named in he game proper) and was not based on any official sources. pic.twitter.com/6ghMEyeN65— Super Mario Wiki (@SMWikiOfficial) October 23, 2018
Another example is the Super Mario Land 2 section. Notice the completely inconsistent mix of plain English names and messy translitterations from Japanese? This is because the names were copied from the wiki's pages pic.twitter.com/WyX6l7fGzv— Super Mario Wiki (@SMWikiOfficial) October 23, 2018
Spot the outlier! Even better, "Kuromame" isn't even the name of that thing in the Japanese script of the encyclopedia (it's "keronpa ball") pic.twitter.com/2eGGqrNSFw— Super Mario Wiki (@SMWikiOfficial) October 23, 2018
It's quite odd that Dark Horse seemingly pulled from the Super Mario Wiki when they had direct contact with Nintendo. It'll be very interesting to see if Dark Horse or Nintendo themselves comment on this matter.