Where does “pterygostomian” come from?

pterygostomian (English) comes from English -ian, from English Hobbesian, from English Hobbes, from English Robert, from Anglo-Norman Robert.

Ancestry of “pterygostomian”, step by step

StepLanguageWordMeaning
1English-ianFrom, related to, or like; One from, belonging...
2EnglishHobbesianInvolving unrestrained, selfish, and uncivilized...
3EnglishHobbesa surname
4EnglishRobert—
5Anglo-NormanRobert—
Every word from Anglo-Norman Robert →Every word from English -ian →Every word from English Robert →