Here's and account of a nini-foot millipede that would keep you inside
if you saw it in your yard.

https://www.science.org/doi/10.1126/sciadv.adp6362

Abstract
The Carboniferous myriapod Arthropleura is the largest arthropod of all
time, but its fossils are usually incomplete, limiting the understanding
of its anatomy, ecology, and relationships. Micro–computed tomography
applied to exceptionally preserved specimens from the Carboniferous
Montceau-les-Mines Lagerstätte (France) reveals unprecedented details of
its functional anatomy, such as the head and mouthparts. Arthropleura
shares features with both millipedes and centipedes. Total-evidence
phylogeny combining morphological and transcriptomic data resolves
Arthropleura alone as a stem group millipede, but the inclusion of the
highly incomplete Siluro-Devonian Eoarthropleura draws it deeper into
the myriapod stem. Arthropleura suggests transitional morphology between
clades united primarily by molecular information and underscores the
value of total-evidence phylogenetics to understanding evolutionary history.

On 10/19/24 8:45 AM, erik simpson wrote:
> Here's and account of a nini-foot millipede that would keep you inside
> if you saw it in your yard.
>
> https://www.science.org/doi/10.1126/sciadv.adp6362
>
> Abstract
> The Carboniferous myriapod Arthropleura is the largest arthropod of all
> time, but its fossils are usually incomplete, limiting the understanding
> of its anatomy, ecology, and relationships. Micro–computed tomography
> applied to exceptionally preserved specimens from the Carboniferous
> Montceau-les-Mines Lagerstätte (France) reveals unprecedented details of
> its functional anatomy, such as the head and mouthparts. Arthropleura
> shares features with both millipedes and centipedes. Total-evidence
> phylogeny combining morphological and transcriptomic data resolves
> Arthropleura alone as a stem group millipede, but the inclusion of the
> highly incomplete Siluro-Devonian Eoarthropleura draws it deeper into
> the myriapod stem. Arthropleura suggests transitional morphology between
> clades united primarily by molecular information and underscores the
> value of total-evidence phylogenetics to understanding evolutionary
> history.

Pharyngula had a recent post on the subject:

https://freethoughtblogs.com/pharyngula/?s=arthropleura

A couple of museums I've been to have lifesized models; they're going to
have to fix the heads.