Use of the Heavy Throwing Spear/Spiculum in Late Roman Armies

[Atheling]

Hi,

More of a military history question than anything abstracted from the rules.

It seems to be the general consensus that the Spiculum came into use (roughly) around 250AD .

My question would be, when did it fall out of use?

So, if I'm putting together an army for the time of the Battle of Strasbourg 357AD would the Spiculum have been used by the Legions?

And of Adrianople 378 AD?

It seems to have fallen out of use by 400AD.

Details seem sketchy to say the least.

I'd love to hear some opinions.

Cheers