Sometimes odd things pop out of fossils.
Here (Fig. 1) is a pterosaur foot (Rhamphorhynchus muensteri, JME-SOS 4009, no. 62 in the Wellnhofer 1975 catalog). Phalanx p4.1 is greatly expanded, yet no longer than it’s counterpart on the other foot.
Maybe you know what this is…
I don’t know what makes toe phalanges expand like this. It is no longer than the slender phalanx on the left pes, but it is greatly expanded, like a balloon. Is it due to disease or injury?
Very few Rhamphorhynchus have such a long pedal digit 4. I have only found one other specimen from about 20 or so that I have examined.
I thought you might find it as interesting as I did.