Troodontidae is a group of bird-like
theropod dinosaurs. During most of the 20th century, troodontid fossils were few and scrappy and they have therefore been allied, at various times, with many
dinosaurian lineages. More recent fossil discoveries of complete and articulated specimens (including specimens which preserve
feathers,
eggs and
embryos, and complete juveniles), have helped to increase understanding about this group. Anatomical studies, particularly studies of the most primitive troodontids, like
Sinovenator, demonstrate striking anatomical similarities with
Archaeopteryx and primitive
dromaeosaurids, and demonstrate that they are relatives comprising a
clade called
Paraves.