In Jain Dharma, the Kālchakra (time-cycle) is definitely a very important concept, but:

• The standard Jain Kālchakra diagrams (showing Utsarpini–Avasarpini, six ārās, sometimes 24 Tirthankars, Kulakars, Chakravartis, etc.) describe time, eras, and spiritual decline/progress.
• They do not have any scriptural concept where “ribs” of a human body are specifically part of the Kālchakra doctrine.

What likely happens is:

• Some modern artists or chart‑makers draw a very detailed cosmology / time‑wheel image and include many symbolic “spokes” or inner divisions.
• These may look like ribs, or someone may label parts in English as “ribs” etc., but this is pictorial style, not an original Jain shastric category of Kālchakra.

From the Jain point of view:

• The authoritative content is: two half‑cycles (Utsarpini & Avasarpini), each with six ārās, fixed pattern of Tirthankars, changes in lifespan, height, spirituality, etc.
• Any extra graphic elements (ribs, gears, ornaments) are not part of the doctrinal definition; they are only design.

So: Yes, a famous Kālchakra image you’ve seen might visually show shapes like ribs, but Jain scriptures describing Kālchakra do not teach anything special about “ribs” in that diagram.