Gilliamella is in the wrong order?

Hi GTDB devs,
I noticed that the genus Gilliamella is classified in the order Enterobacterales by GTDB taxonomy, but by NCBI (and the original taxonomic description paper) it’s in Orbales. In fact, there’s a lot of classifications in Enterobacterales that GTDB and NCBI disagree on (i.e. Arsenophonus, Buchnera, Dickeya, Frischella, and many others). Is this an error or something else?

Dear Jason,

Thanks for your request.

The differences you observe in classifications between GTDB taxonomy and NCBI (original proposals) are based on the rank normalisation that calls for merging or splitting the taxa according to their RED values (see Parks et al., 2018).
The order Orbales has been merged with Enterobacterales in GTDB and this is expression of our taxonomic opinion. Although name Orbales has priority over Enterobacterales, we applied the latter name to the merged taxon because of the wider usage of Enterobacterales as its type genus Enterobacter is dated from 1960.

Please let us know if you have any further questions…

Best wishes,