Question

Today, it’s widely accepted that all of the two-legged meat-eating dinosaurs known as theropods— including T. rex and Albertosaurus—had at least very simple fuzzy feathers covering their bodies. According to the tree you built, what distinguishes the feathers of modern birds and Archaeopteryx from the feathers of other theropods?

Answer 1

The answer is filaments.

In biology. Myofilament, filaments of myofibrils constructed from proteins. Protein filament, a long chain of protein subunits, such as those found in hair, muscle, or in flagella. Part of a stamen, the male part of a flower. A chain of cells connected end-to-end. Hypha, a thread-like cell in fungi and Actinobacteria.