Sofia the Sub-Adult Triceratops Skull
The most complete T. rex ever found, Sue, came out of the Hell Creek Formation in 1990 and sold for $8.4 million, a record at the time. Sofia, a Triceratops, comes from the same layer of Late Cretaceous rock spanning Montana and the Dakotas. Sofia is the kind of dinosaur that Tyrannosauruses are generally believed to have hunted, though there's no evidence that Sue hunted Sofia. Excavated near Marmarth, North Dakota in 2021, Sofia has never been studied, sampled, or published in scientific literature. She's heading to auction straight from the only owner she's had since recovery. The skull is at least 60 percent complete by bone mass, placing her in the top ten percent of privately held Triceratops specimens. Every piece belongs to a single individual, with nothing borrowed from another skull to fill a gap. Her frill bones, the squamosals and parietals, haven't fully fused, marking her as a sub-adult, a growth stage rarely preserved well enough to study.
