I would invite you to entertain the first reading for a second to step into the consciousness of a canon enjoyer where you need proof that Mario and Luigi are human. I believe a running rabbit in Super Mario Galaxy confirms that Mario is a human while lamenting having been caught by a lowly human. A line like this, taking as an expansion of the canon, like in the first Mario movie where it's revealed that Mario's full name is Mario Mario, one would be crushed to learn that Yoshi is not a dinosaur. Check out a fun exerpt from the Mario wiki:

Although most Yoshis have never been seen without their shoes, the appearance of Boshi in Super Mario RPG: Legend of the Seven Stars confirms that Yoshis have three toes on each foot, and also have white pads on the bottom of their feet, as shown in Super Mario Story Quiz Picture Book 5: Mario's Amusement Park (「スーパーマリオおはなしクイズえほん 5 マリオの ゆうえんち」).[14]

And for what it's worth, this was catalogued in the same page about Yoshi:

It is addressed again in Super Smash Bros. for Wii U, where Viridi remarks that there is nothing natural about a male who lays eggs while Palutena asserts that all living beings have both male and female elements.