Variant: jawbone

·    Features – a horizontally rectangular glyph (much longer in the length/x-axis than the height/y-axis), representing a jawbone with teeth:

o A longish element with “knobs” at the ends.

o Each knob can have a tiny dot in the middle.

o A slightly squiggly line runs along the main axis of the jawbone, forking towards the tiny dots in the middle of the knobs.

o Two or (typically) three touching dots run along the top edge of the jawbone. They represent a few remaining teeth in the (skeletal) jawbone.

o The fact that they’re above the bone suggests that it’s the bone of the lower jaw (some skulls have a row of touching dots or small squares hanging from the top of the mouth, suggesting an upper jaw).

·    Subvariants (3)

o A. Asymmetrical (MHD.HJ1.1&3, 0590st):

§ The left side of the bone-jaw has only one knob while the right side has two.

§ The teeth are closer to the left side (though still slightly to the right of the knob on the left).

o B. Symmetrical (MHD.HJ1.2, 0590md, T590a):

§ Both sides of the bone-jaw have two knobs each.

§ The teeth are in the centre, between the two knobs.

o C. Skull (BPK Mural Room 1 Caption 42 D1):

§ This seems to be a very rare variant – only one known instance.

§ It’s known to be cho from the context of cho-ko è chok in the name of the BPK ruler Aj Bahlam Chok (“He of the Jaguar Scattering”?).

§ This name occurs three times in the BPK Murals:

·      Twice with the jawbone form of cho (BPK Mural Room 1 Caption 20 B1, BPK Room 3 Caption 7 A2).

·      Once with the skull form (BPK Mural Room 1 Caption 42 D1).

This substitution enables us to read cho for the skull form. It would have been even better if the AJ and the BAHLAM of BPK Mural Room 1 Caption 42 C1 (the ones accompanying the skull form) were less eroded and more clearly AJ and BAHLAM, but the context of being on the BPK Mural (and being a name) is possibly enough to give at least a little bit of confidence in the reading.

·    MHD statistics (2025-08-23) – a search on MHD with “blcodes contains HJ1” gives 87 hits. The asymmetric and symmetric subvariants are not distinguished by having different codes, but visual inspection reveals that the occurrences of the asymmetrical subvariant far outnumber the occurrences of the symmetrical subvariant (approximately 57 to 13 = more than 4 times as many):

o Asymmetrical subvariant: 57 instances.

o Symmetrical subvariant: 13 instances. It’s interesting to note that Thompson gave only the symmetrical form and not the asymmetrical form, even though the latter are so much more common.

o Unclear: 6 instances. Unclear are, for example:

§ When the left side is eroded, so that it’s not determinable whether there’s one knob or two.

§ When there are two knobs on each end, but the teeth are distinctly to the left.

o Head variant: 1 instance (BPK Mural Room 1 Caption 42 D1).

o No image: 10 instances.