Updated 1.17.2016 with a revised figures based on higher resolution data. On this date, Compsognathus was nested with Struthiomimus.
For many decades
Compsognathus longipes (Wagner 1859, Ostrom 1978, Late Jurassic, quarry unknown, 150 mya, 3 ft (89 cm) long, BSP AS I 563 ) was considered the smallest known dinosaur and something close to its contemporary, the first bird, Archaeopteryx, also from the Solnhofen formation.
Here with very few other theropods to nest with, Compsognathus nests in the large reptile tree (604 taxa) with the very much larger Tyrannosaurus. (updated January 17, 2016) This clade includes the feathered theropod, Sinocallioptery, at its base. Many have wondered if Compsognathus had feathers or not. With modern birds lacking body scales one wonders if subsequent scales are all derived from primordial feathers as the scales on the feet of modern birds appear to be. That would be the opposite of traditional thinking, discussed earlier here.
The number of fingers
in Compsognathus has been an issue largely resolved by Gishlick and Gauthier 2007. Here (Fgi. 2) I found four fingers, all from the left hand, except m1.2 from the right.
The entire skeleton was traced
and these elements were used in a similar fashion to create the Compsognathus reconstruction (Fig. 1). Inside this specimen is the ingested lizard Bavarisaurus.
Gishlick AD and Gauthier JA 2007. On the manual morphology of Compsognathus longipes and its bearing on the diagnosis of the Compsognathidae. Zoological Journal of the Linnean Society 149: 569–581.
Ostrom JH 1978. The osteology of Compsognathus longipes. Zitteliana 4: 73–118.
Wagner JA 1859. Über einige im lithographischen Schiefer neu aufgefundene Schildkröten und Saurier. Gelehrte Anzeigen der Bayerischen Akademie der Wissenschaften 49: 553.