ANATOMY
Families with…
Oral grove: Duoforaminis, Acutiforaminis(most times), nonforaminis, and unumforaminis.
Body: All
Secondary oral grove: Duoforaminis and Acutiforaminis(most, if not all times).
Rivet: Depends on specimen quality, they all had one at one point.
Rivet island: Depends on specimen quality, they all had one at one point.
Slip: Only Unumforaminis
Chip: Occasionally there will be a small dent at the bottom of the body of a Nitripervalida. That is called a chip. So far only been seen in Douoforaminis.
Nib: Not shown on diagram. Can be found on various types of families. A Nib is created when the metal on the back of the nitripervalida is bent in a way that makes it visible from the front. Almost like a reverse chip, but not quite.
The Chip is circled. Photo taken by Jai, a fellow tabist.
PHYLOGENY
RIVET CLASSIFICATION SYSTEM
(credit to my friend jai for proposing the system)
Full: Classified by having both a rivet and a rivet island. Found rarely on pull tabs.
Partial: Classified by having a rivet island but no rivet. Found rarely on pull tabs.
Sub-Partial: Classified by having a rivet island that is barely holding on. Very unusual and rare to see.
None: Classified by having no rivet and no rivet island. Found on most pull tabs.