pinnules
PIN-yulz
Definition
Small, feather-like side branches that extend from the arms of many modern crinoids (sea lilies and feather stars) to increase the surface area for food collection.
Etymology
Derived from the Latin 'pinnula,' the diminutive of 'pinna,' meaning 'feather' or 'wing,' reflecting the small, feather-like appearance of these appendages.
In the news
The article notes that the fossilized crinoid 'Dendrocrinus simcoensis' is apinnulate, meaning it lacks these side branches, which complicates comparisons between its feeding structures and those of modern species.
In the entire 485-million-year fossil record of sea lilies, only one fossil had ever been found with the tube feet the animals catch their food with, and a pair of crushed specimens from a Quebec quarry has now produced the second and oldest case, at about 452
Read the full article ↗ScienceBlog.com