美颌龙科（Compsognathidae）是群小型肉食性恐龙，通常有较传统的外形，生存于侏㑩纪到白垩纪。美颌龙科中有四个属，发现了接近原始羽毛的皮肤痕迹，牠们包括：中华龙鸟、中华丽羽龙（Sinocalliopteryx）、侏罗猎龙、以及美颌龙。证据显示中华龙鸟与中国美羽龙全身覆盖者简单、原始的羽毛，而侏罗猎龙与美颌龙的尾巴与后肢仍覆盖者鳞片。羽毛可能起源于美颌龙科，而其中有些物种只有覆盖部分羽毛。

美颌龙科在虚骨龙类里的演化位置仍未确定，有些人主张美颌龙科是最基础的虚骨龙类恐龙，而其他人认为牠们属于手盗龙类。

Compsognathidae is a family of small carnivorous dinosaurs, generally conservative in form, from the Jurassic and Cretaceous Periods. Compsognathids lie at or near the origin of feathers—skin impressions are known from four genera, Compsognathus, Sinosauropteryx, Sinocalliopteryx, and Juravenator. While Juravenator, Sinosauropteryx, and Sinocalliopteryx show evidence of a covering of simple, primitive feathers, Juravenator and Compsognathus also show evidence of scales on the tail or hind legs.