[llmfan]

OK, I'll ask.

DeepSeek R1 gets it right:

> The species formerly known as Brachiosaurus brancai was reassigned to its own genus, *Giraffatitan*, through a series of taxonomic revisions. The key steps were:

> 1. *Initial Proposal (1988):* Gregory S. Paul first suggested separating B. brancai from Brachiosaurus in 1988, proposing the informal name "Giraffatitan" as a subgenus. However, this was not widely accepted at the time.

> 2. *Formal Reclassification (2009):* Paleontologist *Michael P. Taylor* conducted a detailed comparative study of Brachiosaurus specimens. In his 2009 paper, he formally elevated B. brancai to the full genus *Giraffatitan brancai*, citing significant anatomical differences (e.g., limb proportions, vertebral structures) from the North American Brachiosaurus altithorax.

> Thus, *Michael P. Taylor* is credited with the formal reassignment of the species to the genus Giraffatitan in *2009*.

[thom]

o3-mini-high also gets the right answer, in addition to mentioning Janensch.