Almost forgot but you can also use ZBrush to make the Willosaur parts, and try to atleast make them accurate enough to look like it would belong to the 2005 Willosaur.
You can also try to rip some models for the Willosaur ear by using the Aquatic Willosaur's model that is found in GonzagoGL.
http://www.spore.com/comm/prototypes Find the download that says "GonzagoGL" and try to see if you can find some hidden files that contain the Aquatic Willosaur's model, in which you can try to rip the ears from the model to make them the "Willosaur ear" for the mod i'm requesting.

(You can also rip the tail and frog arms as well)
Credit to NegaTheImpmon9508 from the Spore Wiki for showing pictures of the ripped model of Aquatic Willosaur 2005, which was found in the files of GonzagoGL.
Source:
https://spore.fandom.com/wiki/GonzagoGL (Where I got the information about hidden files which were found in GonzagoGL, that have aquatic willosaur's model.
You can also go here:
https://spore.fandom.com/wiki/Willosaur You can look at the gallery to know that the aquatic willosaur's model was found in the GonzagoGL files. Or how it's referred to the GonzagoGL's files as "aquatictripod".
Hopefully someone does end up making the "More Willosaur Parts" mod request as an actual mod, since it would contain an accurate hand of the 2005 Willosaur, accurate ears, accurate foot and accurate aquatic parts from the aquatic willosaur. (In which the person would most likely rip the ears of the aquatic Willosaur to make it a part along with the aquatic parts of the aquatic Willosaur)