Soft tube feet survived 450 million years, and only one other crinoid has managed it

Wright's framing is the load-bearing part of the announcement: crinoid tube feet work as evidence in roughly the way mammal teeth do, with structural differences reporting where an animal lived and how it fed ^[9]. The traits said to carry that signal are size, spacing and overall form, which vary with the animal's surroundings and feeding method ^[8]. The analogy therefore only cashes out in measurements, and the University of Oklahoma release supplies none. It gives the verdict, that the anatomy of this ancient species was very different from living crinoids ^[10], without the dimensions behind it, and it does not name the journal carrying the description ^[14]. What is defensible today is that a difference was found, not what the difference says about diet.

The rarity figure is worth doing properly rather than admiring. Cole calls the preservation one in a million, and notes that crinoid fossils number in the millions while this is only the second occurrence of soft tissue ^[6]. Two specimens against a record of at least two million is a recovery rate at or below one per million ^[15]. That is not decoration on a press release; it is the ceiling on the evidence base. Soft tissue is also exceptionally uncommon in fossils of early echinoderms as a whole ^[12], so the comparative dataset for feeding anatomy in the group will stay in single digits for a long time.

That bears directly on the larger claim attached to the fossil, that it can help reconstruct the ecology of early Paleozoic oceans, when crinoids were among many animal groups flourishing in reef ecosystems ^[11]. One animal's feeding structures constrain one animal's niche. A reef needs the range, and the arithmetic in the release itself explains why nobody has it. The sober reading is a calibration point: a fixed anatomical observation at 450 million years that any account of how crinoid feeding strategies changed ^[10] now has to accommodate, rather than a working picture of Ordovician reef life.