Depictions of Underarm Phalanxes

[Paralus]

Do not forget that Macedonian phalanxes were renowned for using the hyperpykne order (some attributing its very invention to Philip)

The attribution, though often argued, is unambiguous in Diodorus (16.3.2).

Indeed he devised the compact order and the equipment of the phalanx, imitating the close order fighting with overlapping shields of the warriors at Troy, and was the first to organize the Macedonian phalanx.

Diodorus is not referring to the hoplite phalanx ("compact order and the equipment of the phalanx") but the Macedonian phalanx for the hoplite phalanx was long in the tooth by Philip's time. Later diodorus will write of the epigoni counter phalanx to Alexander's Macedonian phalanx: he is clear and consistent throughout in what he undertands as the "Macedoninan phalanx" and "armed and equipped in the Macedonian manner". He he seems quite certain that his source sees Philip II as the king who first fielded the "Macedonian phalanx".

...they were surely using very long spears with sarauters (which were much more useful in sarissas than in spears because of the balance they added). Sarissas also had to be swung back and forth and the hyperpykne order is attested as one pechis for each man, about 45 cm or 18 inches.

I don't know that the swinging back and forth of sarisae would be that easy (or practicable) when in synaspismos. Eighteen inches per man is essentially man pressed to man - shoulder to shoulder (or hip to hip) and rank to rank.

Ael. Tact.11: The close order takes place when the commander contracts his distances and diminishes the extent of the phalanx, closing rank and file that is lessening both its length and depth; yet still leaving room for locomotion. The joining of shield to shield, or compact order, is effected when the entire phalanx is contracted still further in length and depth; so that on account of the contiguity of soldier to soldier, they cannot incline either to the right or to the left.

Having never reenacted such I'm sticking with Aelian's description of the difficulties in movement in this very tight formation - left or right - and see it largely as defensive (as at Atrax where the phalanx held off several cohorts of Roman infantry hurling pila; Livy, 32.17).

No matter where the sauroter is exactly positioned (we have different accounts of how many yards of the sarissa was behind the pelte), the thing is that the sarissa was used in a swinging mode and would also be turned to target the enemy. This would mean that the sauroter would make analogous movements. The only conclusion I can make is that this was no countable danger for the rear rankers, not because the butt never touched anyone but because even when it did hit against a shield, armor, naked leg, it did not present a real harassment.

Yes: Polybios in his well known discourse allows near a yard behind the phalangite and Aelian says that sarisae could be gripped at the butt and so extend further forward. One wonders if the latter wasn't the more defensive - likely used in synaspismos? Polybios is clearly describing a phalanx "charging" to the attack and this is in the "closed up for action" (close order / puknosis).

As to the sauroter, if the iconic Andronikos suaroter is correctly identified I would not wish for that to be shoved at me. Indeed, I believe it was likely used as a weapon when sarisae shattered and points were left in enemies.