Question: what are the atypical ribs?
Answer: Atypical Ribs Ribs 1, 2, 10 11 and 12 can be described as 'atypical' - they have features that are not common to all the ribs. Rib 1 is shorter and wider than the other ribs. It only has one facet on its head for articulation with its corresponding vertebrae (there isn't a thoracic vertebrae above it).