According to the audio pronunciation provided above, and mind you that’s only one source so I realize have not thoroughly researched this topic, Adam, you, me, everyone else in the world have been correctly pronouncing it plat-uh-puhs.

Let’s explore this hottly debated pronunciation of platypus under the lens of phonics. When a vowel is followed directly by a consonant, it generally makes the short sound so “a” for example would make the sound found in “apple” unless there is an “e” after said consonant or that consonant is a “y” as in “day.” Neither of those cases are evident in platypus. Now, if the word’s 3 syllables were divided differently, there is the possiblilty for that long “a” sound in the first syllable (Pla-ty-pus). With that example, it would have a long “a”, however pairing the t with the y would force the y to sound like long “i” because combining and consonant with a y in the same syllable gives it a long sound (for example “by” has a long “i” sound) The word would then be pronounced Play-tie-puhs. Unless Dick is suggesting that the second syllable have a long “i” sound, there is little chance, with the accepted spelling of platypus, that the first syllable can contain a long “a”.

Of course, there are exceptions to these rules, but I don’t think platypus is one of them

In Dick’s defense, the second entry for platypus on the page provided above does use the phonetic spelling for long a (a with a line over it) that would suggest the pronunciation of the first syllable would be “play” however the audio pronunciation found next to it is still “plat” with a short a.

Your phonics teacher friend,
Edna