From Small Worms to Hammerpedes to Super-Massive Were Worms?

Who knows.... we cant be sure...

But i would assume the sizes we saw was both there maximum sizes... apart from teh Deacon, i have worked out that i feel it would grow to 18ft tall..... taking into account its Human DNA and the growth size in % of a Human Baby to a Human Adult and indeed most Mammals Adult to Birth size..... but this is a at least 18ft size.... if we throw in Xeno sizes i.e Chest Buster to Full Adults then we could be talking 40-50ft tall.... but i would assume the previous 18ft to be the size of a Adult Deacon and thus same size as a Xeno Queen.

It would be interesting to see what becomes of them... but i feel they was merely Plot Device to show a Xeno connection to the Engineers and what they was doing on LV 223.... 

In Alien and the whole franchise i see this as a Organism that procreates and not destroys.. destruction and death is just a bi product of the organisms need to survive and procreate...... if we consider just Alien as cannon and not any other movies or the DC version then the Xeno was a killing machine simple as...

So i would like to assume that the Hammerpedes and Deacon would also both have the aim to procreate and its how would they do so...

I would assume, that the Trillobite having Xeno DNA would grow at a rate of the Xeno, we saw how fast the Xeno went from Chest Buster to Adult.... and this is why Shaw went from being not pregnant to very advanced stage in such a short time, and also how the Trillobite grew to that size too....

With the Hammerpedes, the worms got infected and hybrided and they also vastly grew in size too..... so yeah i assume the Hammerpedes are at fully grown or near enough...

Fifield is a different matter..... but then again the cut we had, his infection was minor with not much Xeno DNA

You make a compelling statement and there are huge implications as a concequence... By that reconing that the Hammerpede would likely not exceed any further growth then that implies there is a finite plateau that any being affected by the black liquid cannot exceed a certain size to far out of its evolutionart body mass. In short: the Liquid has limits and therefore it cuts to the heart of just how effective and destructive is it really?

As with Black Holes, as destructive as they are they are now believed to be essential and central, literally, for Galaxy evolutuon, to thus allow planetary evolution and thus life evolution. The implications for this and for sequels that may further explore this theme of Genisis may suggest that the Black Goo is the liquid version of Black Holes... They are no respecter nor hater of celestial objects that orbit around them, so the case can be made for the Liquid and its effect upon existing life... Some it excellorates and augments, others it ravages and takes away...